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IMESA The official magazine of the Institute of Municipal Engineering of Southern Africa




Value engineering for flexible pavements Martin Murphy Managing

Director, GeoNano Technologies

Sabita Who’s Who

Trends and technologies in asphalt

Concrete expertise for WBHO’s BRT contract

Municipal Focus City of eThekwini

Technology & Innovation BIM’s potential untapped

IN THE HOT SEAT Bell Equipment was built on the specialised machinery concept. That’s the working philosophy behind our growing Versa machine population.” Nick Kyriacos Product Marketing Manager: Mining and Construction & Dawie Ras Engineering Manager: Mining and Construction Specials, Bell Equipment I S S N 0 2 5 7 1 9 7 8 Vo l u m e 4 5 N o . 1 0 • O c t o b e r 2 0 2 0 • R 5 5 . 0 0 ( i n c l . VAT )

Fit for any industry. The Arocs. Approximately 4 billion clay bricks and 13 million tons of cement are manufactured in South Africa every year.* To be in the construction industry takes hard work and dedication and no construction would be possible without trucks and their drivers to transport building material to where it needs to be. Unlock the full potential of the champion in reliability, robustness and body builder friendliness by having a cement mixer or tipper body fitted at a body manufacturer. Build your business with the smart power in construction, the Arocs. Â For more information contact your nearest dealer or visit www.mercedes-benz.co.za/trucks.

*Information sourced from www.claybrick.org & www.theconcreteinstitute.org.za




IMESA The official magazine of the Institute of Municipal Engineering of Southern Africa



INDUSTRY INSIGHT Value engineering for flexible pavements Martin Murphy Managing

Director, GeoNano Technologies

Sabita Who’s Who

Trends and technologies in asphalt

Concrete expertise for WBHO’s BRT contract

Municipal Focus City of eThekwini

Technology & Innovation BIM’s potential untapped

IN THE HOT SEAT Bell Equipment was built on the specialised machinery concept. That’s the working philosophy behind our growing Versa machine population.” Nick Kyriacos Product Marketing Manager: Mining and Construction & Dawie Ras Engineering Manager: Mining and Construction Specials, Bell Equipment I S S N 0 2 5 7 1 9 7 8 Vo l u m e 4 5 N o . 1 0 • O c t o b e r 2 0 2 0 • R 5 5 . 0 0 ( i n c l . VAT )

ON THE COVER As contractor WBHO Roads and Earthworks makes good progress on the bus rapid transit station at Watt Street in Wynberg, Johannesburg, it is being well supported with almost 9 000 m3 of readymix concrete by construction materials leader AfriSam. P6

IN THE HOT SEAT Bell Equipment continues to gain ground as a leading innovator in articulated dump truck (ADT) development. Nick Kyriacos and Dawie Ras discuss pioneering work on the Versa series, a derivative of the OEM’s standard ADT offering. P10




INNOVATION Mammoth culverts set new record

Thought Leadership

Regulars Editor’s comment


President’s comment


Index to advertisers


Cover Story AfriSam concrete expertise for WBHO’s BRT contract





TSAM supports the fight against Covid-19


Building Durban Point Promenade


Durban leads in climate action


Water strategies for a dry city

Towards energy efficient plants 14

State of the asphalt industry


Crash cushions are a lifesaver


Not leaving you in the dust


Opening the way


The leading roads contractor




Innovation BIM’s potential untapped


Circular tank developments


Mammoth culverts set new record 30 Sandton’s smart surveillance solution 31 WATER & WASTEWATER Towards energy efficient plants


Optimising permeate flow in RO plants 52 Supporting municipalities in treatment plant upgrades


Creating water-efficient buildings


Vehicles & Equipment Designed for custom builds


Cement & Concrete Concrete that works fine – without any sand

Labour-intensive Construction



Giving back

Water & Wastewater

Sabita Who's Who

What happened to the EPWP Infrastructure Sector?

Catalytic investments

Municipal Focus

Industry Insight Value engineering for flexible pavements


Incentivising a catalytic development 43

Hot Seat Custom-built ADTs for niche applications


Supporting water and food security 41

Institute News Meet the new 2020-2022 management team

How technology will reshape South Africa


Landfill Landfill containment: cost-effective long-term solutions 65

Geotechnical Engineering Clean power from Kenya's Great Rift Valley


The well-established science of nano technology provides an economical and highly viable proven alternative for maintaining and building road pavement structures. Martin Murphy, Managing Director, GeoNano Technologies, presents his business case and the company’s IMIESA October 2020 1 engineered solutions. P14



ULTRASONIC 80 GHz level sensor with fixed cable connection (IP68)

R9 600.00 VEGAPULS C 11

All advantages of the radar technology:


Creating an inclusive economy

MANAGING EDITOR Alastair Currie SENIOR JOURNALIST Danielle Petterson HEAD OF DESIGN Beren Bauermeister CHIEF SUB-EDITOR Tristan Snijders CONTRIBUTORS Tiaan Bauman, Roger Feldmann, NicoBen Janse van Rensburg, Randeer Kasserchun, Robert McCutcheon, Bryan Perrie PRODUCTION & CLIENT LIAISON MANAGER Antois-Leigh Nepgen PRODUCTION COORDINATOR Jacqueline Modise GROUP SALES MANAGER Chilomia Van Wijk BOOKKEEPER Tonya Hebenton DISTRIBUTION MANAGER Nomsa Masina DISTRIBUTION COORDINATOR Asha Pursotham SUBSCRIPTIONS subs@3smedia.co.za PRINTERS Novus Print Montague Gardens ___________________________________________________


outh Africa’s Economic Reconstruction and Recovery Plan places an emphasis on massive infrastructure build programmes. These will serve as the direct and indirect catalyst for large-scale job creation, inclusive growth and reindustrialisation. Energy, high-frequency spectrum, ports, roads and rail will receive renewed investment, alongside social infrastructure, such as housing, water and sanitation. During his presentation of the plan to Parliament, President Ramaphosa stated, “By the end of June 2020, we had 276 catalytic projects with an investment value of R2.3 trillion.” He added that a “list of 50 strategic integrated projects and 12 special projects was gazetted in July 2020. These catalytic projects have been prioritised for immediate implementation with all regulatory processes fast-tracked – enabling over R340 billion in new investment.” That’s especially welcome news for the hardpressed construction sector, which eagerly awaits the first phases of implementation. But the question remains: When will this implementation take place and what percentage of these roll-outs are expected to be public-private partnerships? Hopefully, ‘shovel ready’ projects will start to come on stream from Q1 2021.

ADVERTISING SALES KEY ACCOUNT MANAGER Joanne Lawrie Tel: +27 (0)11 233 2600 / +27 (0)82 346 5338 Email: joanne@3smedia.co.za ___________________________________________________

PUBLISHER Jacques Breytenbach 3S Media 46 Milkyway Avenue, Frankenwald, 2090 PO Box 92026, Norwood 2117 Tel: +27 (0)11 233 2600 www.3smedia.co.za ANNUAL SUBSCRIPTION: R600.00 (INCL VAT) ISSN 0257 1978 IMIESA, Inst.MUNIC. ENG. S. AFR. © Copyright 2020. All rights reserved. ___________________________________________________ IMESA CONTACTS HEAD OFFICE: Manager: Ingrid Botton P.O. Box 2190, Westville, 3630 Tel: +27 (0)31 266 3263 Email: admin@imesa.org.za Website: www.imesa.org.za BORDER Secretary: Celeste Vosloo Tel: +27 (0)43 705 2433 Email: celestev@buffalocity.gov.za

Rural and municipal roads

EASTERN CAPE Secretary: Susan Canestra Tel: +27 (0)41 585 4142 ext. 7 Email: imesaec@imesa.org.za

Among the initiatives planned within the next six months are upgrades to rural and municipal road infrastructure, incorporating labour-intensive construction (LIC) methods. That provides an opportunity for the government and industry to revisit the viability and track record of past Expanded Public Works Programme (EPWP) projects. We need to investigate and apply the technologies and techniques that have proven to be successful locally and internationally. Rather than providing purely temporary work, the EPWP can serve as an excellent platform to upskill and empower communities with sustainable construction skills. In this issue, Professor Robert McCutcheon, a renowned academic, presents his thoughts on the subject.

KWAZULU-NATAL Secretary: Ingrid Botton Tel: +27 (0)31 266 3263 Email: imesakzn@imesa.org.za NORTHERN PROVINCES Secretary: Ollah Mthembu Tel: +27 (0)82 823 7104 Email: np@imesa.org.za SOUTHERN CAPE KAROO Secretary: Henrietta Olivier Tel: +27 (0)79 390 7536 Email: imesasck@imesa.org.za WESTERN CAPE Secretary: Michelle Ackerman Tel: +27 (0)21 444 7114 Email: imesawc@imesa.org.za FREE STATE & NORTHERN CAPE Secretary: Wilma Van Der Walt Tel: +27 (0)83 457 4362 Email: imesafsnc@imesa.org.za All material herein IMIESA is copyright protected and may not be reproduced either in whole or in part without the prior written permission of the publisher. The views of the authors do not necessarily reflect those of the Institute of Municipal Engineering of Southern Africa or the publishers. _____________________________________________

Within the South African roads sector, there is a wealth of experience and expertise to draw from across the OEM, contracting, consulting and roads agency segments. We have a national road network that remains one of the most advanced in the developed and developing world. The key challenge is the need to address the maintenance backlog on our secondary and low-volume roads, since this has a direct impact on government’s initiatives to revitalise our struggling rural economies. We have the solutions, thanks to South Africa’s highly advanced asphalt industry – globally recognised as a pioneering sector. Led by our academics, engineers and producers, the local industry continues to push the boundaries in terms of materials, product innovation and construction techniques. In this month’s Sabita Who’s Who feature, we showcase a range of excellent examples. They include cost-effective solutions that stretch and optimise maintenance and construction budgets, without compromising on standards.

A restart The Economic Reconstruction and Recovery Plan is a logical starting point for the building of a new economy. It’s also an opportunity to reform elements of maladministration that have impeded the intended goals and targets of the National Development Plan 2030. These and other strategies support and drive the change we need to see within the context of South Africa’s unique history. However, their motivation and focus are not exclusive and are shared equally by all private and public leaders globally. It’s encouraging to see that there’s a collective will to build more coherent and participative societies. The proof, of course, is in its execution.

Alastair @infrastructure4



Infrastructure News

IMESA The official magazine of the Institute of Municipal Engineering of Southern Africa



Cover opportunity




Value engineering for flexible pavements Martin Murphy Managing

Director, GeoNano Technologies

Sabita Who’s Who gies Trends and technolo in asphalt

se Concrete experti for WBHO’s BRT contract

Municipal Focus City of eThekwin i

The ABC logo is a valued stamp of measurement and trust, providing accurate and comparable circulation figures that protect the way advertising is traded. IMIESA is ABC audited and certified.

Pavement innovation

To our avid readers, check out what we are talking about on our website, Facebook page or follow us on Twitter and have your say.


Novus Holdings is a Level 2 Broad-Based Black Economic Empowerment (BBBEE) Contributor, with 125% recognised procurement recognition. View our BBBEE scorecard here: https://novus.holdings/sustainability/transformation


Technology & Innovat


BIM’s potential untapped


That’s the machinery concept. built on the specialised machine population.” Bell Equipment was Versa & behind our growing Mining and Construction working philosophy Marketing Manager: Equipment Nick Kyriacos ProductMining and Construction Specials, Bell Manager: Dawie Ras Engineering VAT ) 00 (incl. er 2020 • R55. No. 10 • Octob 8 Vo l u m e 4 5 ISSN 0257 197

In each issue, IMIESA offers advertisers the opportunity to get to the front of the line by placing a company, product or service on the front cover of the journal. Buying this position will afford the advertiser the cover story and maximum exposure. For more information on cover bookings, contact Joanne Lawrie on +27 (0)82 346 5338. IMIESA October 2020



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a rewarding two years The last two years in office have flashed past and the time has come for me to hand over the reins to our new incoming President. It gives me great pleasure to welcome Bhavna Soni, a professional engineer working for the City of eThekwini, as our new President for the 2020-2022 period.


his is a major milestone in our history, since Bhavna becomes IMESA’s first woman President. As Immediate Past President, I look forward to working with her, alongside my fellow IMESA Officer Bearers, as we prepare the groundwork for the next 12 months. This includes our annual conference, which will be held in November 2021 at the Cape Town International Convention Centre with the theme ‘Synergy through Engineering’. Despite Covid-19, our Exco and national branch committees were still able to maintain communication and momentum to deliver on our objectives during 2020. If anything, the pandemic has reinforced the crucial role that municipal engineers play in delivering essential services. Covid-19 also highlighted where we need to focus most to add value. These areas include water demand management and sanitation.

Objectives achieved The top two items I set out to achieve were the acceleration of IMESA training, with the introduction of free CPD accredited training for municipalities; and enhanced engagement with fellow voluntary associations and government authorities. With reference to training, I am happy to report that the first set of technical courses, free of charge for municipal employees, has been rolled out and been well received. The ‘Capacity Building in Urban and Regional Planning’ course was presented in Durban, Kimberley, Nelspruit and Newcastle, and these were well attended. It was great to welcome

technical staff from our outlying municipalities. A further series is scheduled over the coming year. We also held our first ‘Small Coastal Storm Water Outlets’ training course in Durban at the onset of 2020. This project was initiated by Stellenbosch University and sponsored by IMESA with the objective of establishing comprehensive design guidelines and construction recommendations for small coastal stormwater outlets.

Water strategies and stakeholder engagement An overriding priority is to focus on the measures needed to address South Africa’s water security threats. These are progressively worsening due to ageing pipeline infrastructure and compounded by a spate of severe droughts. Guidance regarding the reuse and reclamation of water by local authorities is needed. In response, we are working with the Water Research Commission to develop a suitable training programme. Allied to this is our water conservation and water demand management initiative for water services authorities, where IMESA sponsored and supported the development of a pre-feasibility tool. The pilot was trialled during initial workshops and we look forward to rolling out the use of this tool in municipalities in 2021. Further projects to develop guidelines and training materials for specific municipal requirements have been included in the budget for our 2020/21 financial year. In terms of engagements with external bodies,

meetings have been held with ECSA, Salga, CESA, Saice, the WRC, as well as CoGTA and National Treasury representatives. These meetings will continue and IMESA expects positive outcomes from these interactions.

In closing Last, but not least, I’d like to thank you – our members – for your continued support of IMESA. A special welcome also to our new members, many of whom are young engineers just starting out on their career paths. A special word of thanks to the IMESA head office staff, Exco and branches. You are the critical interface with our municipalities and their communities. Together, you have all made a lasting and sustainable difference, ensuring that IMESA continues to grow from strength to strength. It has been an honour to serve as your President and to welcome Bhavna as the new President of IMESA.

Randeer Kasserchun, president, IMESA

IMIESA October 2020



AfriSam concrete expertise for WBHO’s BRT contract As contractor WBHO Roads and Earthworks makes good progress on the bus rapid transit (BRT) station at Watt Street in Wynberg, Johannesburg, it is being well supported with almost 9 000 m3 of readymix concrete by construction materials leader AfriSam.

AfriSam dedicated between 14 to 17 trucks to the job of servicing WBHO’s concrete pumps during the large continuous pours of around 550 m3 each. AfriSam has extensive experience in achieving special mixes and ensuring reliable concrete supply for major bridge works


he underground BRT station at the Watt Street interchange is part of the City of Johannesburg’s Rea Vaya system to integrate and improve public transport facilities. The Watt Street station will serve the Rea Vaya bus route from Sandton to Alexandra, as well as from Parktown to Alexandra. The project is driven by the Johannesburg Development Agency. According to Daniel Kwele, construction manager at WBHO Roads and Earthworks – a division of WBHO Construction – the early work from July 2018 included the demolition of the existing Watt Street bridge and the relocation of telecommunication and other existing services. “The earthworks for this project were substantial, involving over 100 000 m3 of material being moved,” says Kwele. “To limit our impact on the traffic pressure in the area, we moved most of this volume at night while concentrating on concrete structures during the day.” The earthworks allow for the bus lanes to descend between reinforced earth walls


IMIESA October 2020

To the north of the bus station, the most notable structures are the twin viaduct bridges, resting on 220 end-bearing piles and over 70 footings

into the underground station, above which a new interchange is constructed for mixed traffic. The first concrete work included the installation of 342 lateral support piles on the southern portion of the main bridge over Pretoria Main Road, each with pile caps on which would rest 244 precast concrete beams. This section of the project also included installing 18 km of ground anchors, 10 km of soil nails and 13 000 m2 of shotcrete. A spine beam in the midsection is fixed on one end and supports the 37 t beams all the way on to the northern bridge section. “To the north of the bus station, the most notable structures are the twin viaduct bridges, resting on 220 end-bearing piles and over 70 footings,” he says. “The bridges required two very large continuous concrete pours – one in February 2020 and another in June 2020.” Further north are four reinforced earth walls to allow for the mixed lanes to tie back from Chadwick Street into Pretoria Main Road.

Planning and teamwork Randal Chetty, key accounts manager, AfriSam, highlights how the experience from previous contracts with WBHO helped to strengthen the working relationship. “Our pre-contract meeting created a good foundation for everyone to know what’s expected, and from there the schedules were generated for the deliveries of the concrete itself,” says Chetty. “The big continuous pours in particular demand a huge amount of planning, so it was vital that everyone worked together to make these successful.” The site is located just a kilometre from the AfriSam Wynberg readymix plant, and AfriSam dedicated between 14 to 17 trucks to the job of servicing WBHO’s concrete pumps during the large continuous pours of around 550 m3 each.

Expert mix formulation and delivery “This was a highly specified project in terms of concrete mix designs, requiring considerable upfront collaboration with the engineers to approve the designs within the

COVER STORY Sanral specifications,” he says. “We were also able to demonstrate our years of previous experience in the supply of durable concrete.” Kevin Naidoo, operations manager for AfriSam’s central plants, notes that the company has extensive experience in achieving special mixes and ensuring reliable concrete supply for major bridge works. These include the ambitious Allandale interchange in Midrand, and the pedestrian bridge near Grayston Drive in Sandton. In large continuous pours for this kind of application, the window period for pumping and placing the high-spec concrete tends to be limited – mainly due to the high cement content in the mix. “This meant that we had to have fresh concrete on-site all the time, with no queueing of trucks,” says Naidoo. “The laboratory at our Jukskei plant – just north of the project – also assisted with checking the quality of our 150slump mix.” On-site were two pumps with a twin-discharge facility, feeding freshly mixed concrete from well-synchronised AfriSam trucks to the northern and southern side of the main bridge. To ensure the consistency of the mix, the Wynberg A-plant was used to source most of the concrete for the large pours. “Consistent aggregate supply was vital to this process, so we arranged for extra material to be brought in and stockpiled,” he says. “It was also important to have senior management on hand during the pours to ensure that everything ran smoothly.”

Pre-pour meetings Kwele agrees that the pre-pour meetings between the contractor and the supplier really helped to foresee and mitigate any challenges. “The pours became a smooth process, thanks

to the commitment from AfriSam’s senior management, for which they deserve much credit,” he says. Naidoo emphasises that AfriSam placed its technical experts both at the Wynberg plant and on the project site to coordinate the various elements of each pour, with slump tests being conducted on every truck leaving the plant. Considerable attention was placed on quality and testing, irrespective WBHO Roads and Earthworks is making good progress on the BRT station at Watt Street in of the size of the pour. WBHO Wynberg. On-site were two pumps with a twinalso had its own concrete testing discharge facility, feeding freshly mixed concrete procedures being conducted at from well-synchronised AfriSam trucks to the northern and southern side of the main bridge the site. “To make sure that the stringent say that we are one of the few who can do this tolerances demanded by the South reliably and professionally,” he says. African National Standards were complied Among the operational innovations that were with, concrete samples were also taken jointly developed by WBHO and AfriSam was from every truck arriving on-site and tested,” the implementation of ‘dry runs’ before large he says. pours – to mitigate the risk of disruption at Logistics and execution site. He notes that the project team had In preparation for AfriSam’s involvement, Kwele been delayed on numerous occasions by and his team also spent some time at the community issues and taxi disruptions, among Wynberg plant, where AfriSam demonstrated others, so the dry runs proved a valuable its quality processes and logistics systems for strategy to ensure that the pour was not the various construction materials. interrupted once it began. Over 30 local small “For us as the construction team, every business contractors have been engaged on project presents its own technical and other the project. challenges,” says Kwele. “On this project, we really appreciated the effort that AfriSam put into this contract, which has been vital in ensuring its success.” Chetty points out that not many concrete suppliers have the capacity to conduct the pour sizes required for this contract, within the timeframe required – while still servicing all its www.afrisam.co.za other customers timeously. “We are proud to

The bridges required two very large continuous concrete pours – one in February 2020 and another in June 2020

IMIESA October 2020



Meet the new 2020-2022 management team


raditionally, the new President is inaugurated at the annual IMESA Conference in October, but that was not possible this year due to Covid-19. The next annual conference will now be hosted between 17 and 19 November 2021 in Cape Town in collaboration with the International Association for Water, Environment, Energy, and Society.

In the meantime, IMESA’s Exco team will continue to forge ahead in delivering the Institute’s mandate of promoting and capacitating municipal engineering excellence across South Africa. The 20202022 Office Bearers will be led by Bhavna Soni, who becomes IMESA’s first woman President.

At the end of each two-year cycle, a new IMESA President takes the helm for the next 24-month cycle, supported by the Immediate Past President as deputy and two Vice Presidents. These are ex-officio members of Council together with the Operations and Technical Directors that comprise the executive committee.




IMIESA October 2020

Bhavna Soni matriculated in 1982 and obtained her BSc Civil Engineering in 1987 from South Gujarat University in India. She married a South African and settled here in 1990. She has been a registered professional engineer since 2008. Bhavna worked in the consulting field as a structural engineer prior to joining eThekwini Municipality in 1997. She subsequently worked in the Design Department, working on reservoir and pipeline projects. She then moved to the Planning Department, where her duties involved designing bulk water infrastructure for the eThekwini region. In 2005, Bhavna was

promoted to the position of manager: Rural Systems. Later in 2008, she was promoted to senior manager: Water Operations, combining rural and urban areas. Bhavna also acted as deputy head for water and waste operations for two years before being appointed to her current position as a deputy head: Engineering for eThekwini’s Water & Sanitation Unit. Currently, she is responsible for the design and implementation of water and wastewater infrastructure, as well as providing strategic direction to reduce non-revenue water within the eThekwini region. Bhavna joined IMESA in 2008 and has served on Exco since 2014.


DEPUTY PRESIDENT (AND IMMEDIATE PAST PRESIDENT) Randeer Kasserchun is deputy head of eThekwini’s Coastal Stormwater & Catchment Management Department, Engineering Unit. He matriculated in Durban and graduated with a BSc Civil Engineering from the University of KwaZulu-Natal (Westville) in 1994. During 1995-96, he attended the School of Public Policy and Development Management at the University of KwaZulu-Natal where he obtained a Postgraduate Certificate in Development Management. Randeer joined the City of Durban as a graduate hydraulic engineer in 1995. He registered as a professional engineer in 1997. He has been practising in the hydrology and coastal engineering fields for the past 20 years.

He is a corporate member of the South African Institution of Civil Engineering (SAICE). He occupied the post of IMESA Vice President (Technical Division) for 2015-16 and 2016-18. He was also President of IMESA for the 2018-20 period. Randeer was the engineer on the Umhlanga Pier, which received the SAlCE Durban Branch Award for Technical Excellence in 2007. In 2008, he received the IMESA National Award (Structures Category) for this project. In 2014, the Umhlanga Pier was declared the ‘World’s most beautiful pier’ by news channel CNN. He was also the engineer on the Sandile Thusi Pier, which won the IMESA National Award and the CoGTA KZN Award for Most Innovative Structure in 2012.






Pieter Myburgh studied at Jim Fouche High School, Bloemfontein, before going on to complete his BEng (Hons) Civil Engineering at the University of Pretoria in 1992. He has worked mainly in traffic and transportation engineering and currently holds the position of senior manager: Streets and Stormwater at Mossel Bay Local Municipality. He joined IMESA in 1992 and is an active member of the Southern Cape/Karoo Branch, serving on the branch committee and previously as Branch Chairperson. He served on IMESA’s Council for several years before being elected to Exco in 2010, where he held the portfolio of Technical Director: Roads, Transportation and Stormwater, until he was elected Vice President: Technical for the 2018-20 period. Pieter has now been re-elected to continue overseeing IMESA projects as Vice President: Technical for 2020-22.

Geoffrey Tooley completed his BSc Civil Engineering in 1987 at the University of Natal, Durban. He started work at the Durban City Council in 1990, now eThekwini Municipality, and registered as a professional engineer in 1998. He held the position of manager: Stormwater Design from May 2001 to Feb 2006. In March 2006, he was appointed manager: Catchment Management at eThekwini. As manager of the Catchment Management section, he is responsible for work relating to the rivers in eThekwini, including floodlines, stormwater management plans, master drainage plans, rainfall distribution figures and erosion control, as well as adaptation plans related to flooding.

Geoffrey was part of the team that developed the Municipal Adaptation Plan for the Water Sector – adopted by council in 2009. He also managed the development of the new stormwater management policy for eThekwini, passed through council in 2014. Additionally, he was part of the team that developed the Durban Climate Change Strategy. Geoffrey was the co-author and presenter of a paper titled ‘Adaptation in practice: Durban, South Africa’ at the 1st World Congress on Cities and Adaptation to Climate Change hosted by ICLEA in Bonn, Germany, in May 2010. He is a member of the Water Research Commission reference groups for: • A  lternative technology for stormwater management (K5/1826) • Influence of catchment development on peak urban runoff (K5/1752) • W  ater sensitive urban design (WSUD) for South Africa: Framework and guidelines (K5/2071). Previously, he has held the Operations Director portfolios for Bursaries, CPD and Head Office Support at IMESA. He lectures for SAICE in Durban on stormwater design, as part of their continued education programme.

IMIESA October 2020



Bell Equipment continues to gain ground as a leading innovator in articulated dump truck (ADT) development. IMIESA speaks to Nick Kyriacos, product marketing manager: Mining and Construction, and Dawie Ras, engineering manager: Mining and Construction Specials, about pioneering work on the Bell Versa series, a derivative of the OEM’s standard ADT offering.

Custom-built ADTs for niche applications Where does the Versa slot in within the Bell ADT line-up? NK Our manufacturing centre for the global distribution of ADTs and the Versa series is based at our Richards Bay factory and head office in South Africa. The introduction of the Versa follows intensive research and development (R&D) in the local market, where the first prototypes went through a rigorous field evaluation process. Thereafter, commercially approved units began to roll off the production line. The local market feedback has been excellent, and we are now steadily introducing

the Versa to our international customer base. Each Versa truck is a custom build working off the proven and latest-generation Bell E-Series ADT platform, which comprises the B25E, B30E, B35E, B40E, B45E, B50E and B60E range. So far, we’ve developed solutions for a diverse customer base within South Africa and further afield in Africa and the world. A recent example is the production of a purposebuilt solution for German OEM Streumaster, in Europe. One of Streumaster’s proprietary cement spreader systems for road stabilisation has been

mounted on and integrates with a Bell B25E powerhead (or truck tractor) and its chassis.

Can customers choose different engines and drivetrains? DR All our ADTs and Versa units are fitted with Mercedes-Benz engines. Customers select the applicable E-Series power head as the base. From there, we modify the rear-end section – either on a standard, shortened or extended chassis – to support the solution required by the customer. Our custom builds for timber trucks illustrate our design flexibility. We offer numerous variations because we understand that every site has its unique conditions. A case in point is the especially steep terrain that characterises the forestry region in Nelspruit, Mpumalanga.

In response, we’ve developed a more powerful 240 kW B25E equipped with the B30E engine and drivetrain that packs a real punch. For customers in this region, it’s an ideal solution – the right-sized truck for the application, with the torque to conquer the rolling elevations. As is traditional for ADTs, all transmissions are automatic. This translates into improved fuel consumption, extended engine life, and the right level of control in rough terrain applications. All our axles are developed in-house and here we provide the option of fitting either dry or wet disc brakes. Dry brakes are fitted as standard on our smaller trucks, but on larger trucks the wet brake option, which adds to the upfront capital cost of the machine, is favoured due to long lifespan, which justifies this expense. Wet disc brakes provide far greater stopping power, which is especially important for heavier loads. Wet disc brakes also last far longer due to the limited contact of the friction plates. Where trucks operate in marshy conditions, wet brakes are also essential since they are designed as a fully sealed system. As a value-added offering, we now include wet discs as a standard feature on the B30E powerhead.

DID YOU KNOW? Dawie Ras (left) and Nick Kyriacos, Bell Equipment


IMIESA October 2020

To date, more than 30 000 ADTs have been produced at Bell Equipment’s Richards Bay factory.

HOT SEAT What type of chassis setups are available? NK There are various options. These comprise the standard chassis, an extended chassis, a 4x4 hauler chassis, a 4x4 short chassis, a standard chassis with crane mounting, and an extended chassis with crane mounting. The 4x4 short chassis can be fitted with a fifth wheel attachment where the intention is to tow interchangeable systems, such as trailers, grid rollers and impact rollers. A classic example of our out-of-the-box thinking is the Versa timber truck forwarder. This model originally started out as a standard Bell ADT designed for timber haulage. However, after numerous customer requests for a forwarder unit and without having one in our product line-up at that stage, the large number of potential orders justified the R&D effort to design a new niche product. In the end, we developed a special ADT fitted with a slightly bigger and dual-faced cab. Inside the cab compartment is the standard steering wheel. A swing-around seat arrangement then enables the driver to face to the rear and operate a set of joysticks that control a chassis-mounted crane for loading and unloading logs. As a further plus, the driver can also stay in this reversed position and drive the truck using the joysticks to manoeuvre into a better position.

Is the quarrying sector a growth market? NK Yes, definitely – with good traction to date from both the South African and European markets. The Bell Versa B30E 4x4 is very popular with quarry and readymix operators in France. Locally, we demonstrated this unit for a quarry owner in Durban, where the feedback has been excellent. This client currently employs standard 6x6 ADTs, so it was interesting to do a side by side comparison. While the B30E 4x4 may not provide quite the same off-road, deep-mud performance as a 6x6, it’s still an all-wheel-drive machine. From the client’s perspective, our 4x4 competed favourably with the 6x6 in terms of

payload performance. On top of this, the 4x4 displayed superior handling within the quarry, greater fuel efficiency, and was better suited to manoeuvring the tight turns on-site. Faster cycle times contribute to a lower cost per tonne. We plan to run further demonstrations across South Africa and believe it’s the beginning of a trend in the quarrying sector.

What can customers expect from custom builds? DR If it comes with a standard base, with no drivetrain modification, and a straightforward application equipment fitment, we can turn a customer order around quickly. A Versa customer is coming to us because they have a specific solution in mind and that solution is not available in the open market. Design flexibility and class leadership on our ADT series are what make the Versa the logical choice for tailormade solutions. We have a dedicated application equipment design team in Richards Bay working for our local and global customer base. This design team currently comprises six mechanical and two electrical engineering specialists.





Standard chassis

B30E Extended chassis

B35E Hauler chassis - 4x4


Standard Cab

Short chassis - 4x4


Standard chassis crane mounting


What are standard features common to the Versa series? NK All ADTs come with a standard ROPS/ FOPS certified cab, which differentiates it from a tipper truck. Safety is key; here, features include our fail-safe park brake system. We also have an emergency steering system: if the power cuts out, the truck can still be steered using its momentum. In cab, the controls no longer have rocker switches: they have been replaced by a sealed switch module with exceptional functionality. The central display unit is also user-friendly, enabling the operator to carry out daily checks, cross-check inspection lists, and carry out machine diagnostics. Another interesting feature is an auto spin-down function for the turbo once the machine is parked. The engine will shut off only once temperature levels have normalised.

Extended chassis crane mounting

What is the future direction in terms of R&D? NK Bell Equipment was built on the specialised machinery concept. In the 1950s, our founder, Irvine Bell, offered specialised machines to meet the needs of the sugar industry and in the same way our engineering team has always worked to meet customer requirements, no matter how impossible they may seem to be. That’s the working philosophy behind our growing Versa machine population.


IMIESA October 2020



State of the asphalt industry The Southern African Bitumen Association (Sabita) and its members are committed to best-in-class standards. IMIESA talks to Saied Solomons, CEO, Sabita, about technical developments, pavement and transportation trends. What are the key trends shaping the future of asphalt pavements? SS Asphalt has a history of providing value to road authorities, as well as users, and continued efforts are being made to further improve its durability. This entails better scientific understanding of the composite materials, as well as considering a mix design approach that balances the various modes of pavement distress, taking into consideration mix ageing, traffic, climate and location. The global trend in road construction – focusing on improved project execution at lower cost through utilising digital equipment enhanced with artificial intelligence – will no doubt find fertile ground locally as well. The advent of autonomous and electric vehicles brings with it its own exciting possibilities for accommodating the needs of this new type of mobility.


IMIESA October 2020

While there are many futuristic scenarios being played out globally, we’ll have to sift through these and adopt what is most appropriate for our needs. Sustainability will continue to shape our thoughts and actions as an imperative for a better future.

Is greater emphasis being placed on reclaimed asphalt? Reclaimed asphalt is considered a valuable material source in the production of asphalt and is probably the material that is most recycled. To further this sustainability drive, much effort has gone into better understanding the optimal use of it in asphalt mixes. In 2009, Sabita funded the development of a technical guide to assist industry in its use. This document has since seen numerous revisions, with the latest 2019 version currently being reviewed to incorporate global best practice.

What are Sabita’s Technical Committees working on right now? A permanent agenda item is the review/update of Sabita’s technical manuals. Recent and current work saw updates to Manual 35/TRH 8: Design and use of asphalt in road pavements; Manual 36: Use of Reclaimed Asphalt in the production of asphalt; Manual 38: Health and safety in construction laboratories; TG 1: The Use Of Modified Bituminous Binder In Road Construction; TG 2: A Guideline for the Design and Construction of Bitumen Emulsion and Foamed Bitumen Stabilised Materials. To support the subcommittee focusing on material testing, the CSIR was commissioned to develop Manual 39: Laboratory testing protocols for binders and asphalt. Currently in the making is Manual 37/TMH 5: Sampling methods for road construction materials TG3: Asphalt Reinforcement Guideline and Manual 40: Design and construction of surfacing seals. Manual 40 details the latest in surface treatments, incorporates TRH3 as well as other Sabita manuals and spans over 500 pages.

The implementation of Performance Grade specifications for bitumen is also high on the agenda, with a dedicated subcommittee providing the necessary focus. Being a member of the relevant SABS committees enables alignment of the various SANS specifications with the latest technical know-how as per the Sabita guides. As but one example, SANS 1083, which currently only covers aggregates for concrete, will in future contain specifications for use in all areas of construction (including roads).

Are current road funding models working? In South Africa today, many people are paying more road use tax with the fuel levy than their comparative fair share of road

Saied Solomons, CEO, Sabita


use demands. They are also paying in personal time due to congestion and increased vehicle operating costs. Many believe that the fuel levy should continue to be the answer. But with rapid urbanisation occurring the world over and South Africa being no exception, the provision of adequate capacity and the management of trunk roads in urban areas face the biggest challenge. When the fuel levy was introduced in the early parts of the last century, the urbanisation phenomenon was hardly on the horizon. The issue then was more about connecting the various parts of South Africa. The fuel levy has played its role, but such a road pricing mechanism is woefully inadequate today to deal with real 21st century issues such as urbanisation, the imminent introduction of electric vehicles, air quality, congestion, and safety. To adequately deal with this new paradigm, a totally different approach is required. Any new road charging system considered must be easy to understand, with greater transparency, in order to provide confidence to the road user that government’s investment in road infrastructure is in their interest.

Would it be more cost-effective to seal low-volume roads? The answer is an overwhelming yes! The current Draft Roads Policy for South Africa stipulates that the roads sector must: (a) satisfy citizens’ right of access to constitutionally protected basic services, and (b) maximally contribute to economic growth. If one considers just the right to have efficient and effective access to healthcare services and basic education, then the provision of all-weather surface roads become an imperative. Many studies into this matter have concluded the same and the latest paper by Dr Matthew Townshend and Professor Don Ross, entitled ‘A road investment prioritisation model for South Africa’, once again provides well researched guidelines to tackle this challenge.

How serious is South Africa’s roads maintenance backlog? While government estimates the backlog to be around R200 billion, new research by UCT’s Professor Don Ross and economics consultant Dr Matthew Townshend found that it is somewhat over

R400 billion. The difference is largely attributed to out-ofdate government data and the extent of the country’s network considered in the backlog. The research document found the provincial road maintenance backlog to be R150 billion, while the municipal road maintenance backlog was estimated at R242 billion. The situation certainly does not bode well for the future of the road network, given that the annual allocation to roads falls short of what is required merely to maintain the network’s current standard.

How are bitumenstabilised materials evolving? The first technical guideline on the subject published in 2002 was followed by a second version in 2009, titled A Guideline for the Design and Construction of Bitumen Emulsion and Foamed Bitumen Stabilised Materials TG2. This edition combined BSM-emulsion and BSM-foam in one document, due to the many similarities between the materials, while recognising material science differences between the two approaches. The latest version, published in August 2020, takes into consideration data collected

from thousands of kilometres of all types of road structures that have received BSM treatment over the last decade. Significant research into the behaviour and performance of BSMs has been undertaken, focusing on mix design, classifying materials for design, and structural design – all of which have been incorporated into this guideline.

How do you see the market unfolding in 2021? The last few years have been very difficult for the road construction industry and the pandemic has added to these woes. Given the work being done by the Public-Private Growth Initiative, I am optimistic that we will see a better industry in 2021. Government procurement processes remain one of the major stumbling blocks, so solving this issue must be given priority.

SABITA’S ASPHALT ACADEMY The Asphalt Academy offers numerous training courses on the design, use and application of bituminous materials in road construction. These NQF 5+ courses are scheduled and executed as part of the South African Road Federation training suite. Courses at level NQ4 and below are offered on demand, except for the Material Testers courses which are scheduled. Great strides have recently been made towards the introduction of an ISO 17204 certification scheme for material testers in civil engineering laboratories. This new training scheme will kick off with a pilot run towards the end of 2020.


Value engineering for

flexible pavements

The well-established science of nano technology provides an economical and highly viable proven alternative for maintaining and building road pavement structures. Martin Murphy, Managing Director, GeoNano Technologies, presents his business case and the company’s engineered solutions.


perating nationally and internationally, GeoNano Technologies is widely regarded as a pioneer in the development and adoption of proven solutions for road pavement designs and construction. Material evaluation and bitumen emulsion tests are conducted in-house at the company’s materials and product research laboratory in Germiston, Gauteng. “We are proud to be involved with the highest ranked Faculty of Engineering in Africa, having sponsored several final-year and post-graduate students, enabling us to build the foundation for a sound engineering background to our products,” Murphy explains. “Through the involvement of these students and academics, we have identified the best available new-age (nano-size) technologies. We’ve improved products and developed optimal design methods based on fundamental scientific principles, making them universally applicable. Our products can be used with confidence to add value and contribute to the cost-effective, much needed service delivery of transportation infrastructure,” he continues. A considerable reduction in road unit costs can be achieved by using material-compatible


IMIESA October 2020

and safe modifying agents that chemically modify traditional stabilising agents, such as bitumen emulsions (or equivalent). This modification enables the stabilising agent to chemically attach to the particles of naturally available stone/gravel/soil materials. The chemical attachment (absent in the normal use of bitumen products, which relies on electrical and mechanical forces through interlocking and absorption to gain strength) considerably improves bond strengths. These high chemical-bond strengths enable the use of naturally available materials in all pavement layers of roads, meeting (usually exceeding by some margin) the engineering requirements in terms of stresses, strains and durability in any pavement layer.

Understanding mineralogy The key to the successful use of modifying agents is in the science associated with the mineralogy of the materials and the identification of a compatible modifying agent with high inter-element bonds – i.e. a sound scientific chemical basis of design. The small particle sizes (nano-size) of the modifying agents enable a large coverage area, (1 litre of nano-sized material could exceed the

coverage area of 1 000 litres of bitumen). This allows for deep penetration into the material. The small particles also attach to secondary minerals found in naturally available material and render them hydrophobic (water repellent). Hence, any possible negative influence of these secondary minerals on the future behaviour of a road can effectively be neutralised using a scientifically designed, material-compatible modifying agent in the emulsion.

NME agents The proven concept of these New-Age modifying agents of emulsions (NME) has been demonstrated with the scientific testing and use of NME stabilisation of in-situ materials (ranging from fine Kalahari sands to the use of G8/G7 materials in base/sub-base layers, etc.) in the design and construction of several roads. Accelerated pavement testing (APT) has also Martin Murphy, Managing Director, GeoNano Technologies

Accelerated pavement testing (APT) has been completed on some roads by one of South Africa’s provincial roads departments

been completed on some roads by one of the provinces. As expected, (based on the scientific design approach followed through the analysis of the mineralogy of the materials and designing of a material-compatible modifying agent), the results of these tests far exceeded the engineering requirements. This resulted in considerable cost savings (materials as well as time of construction). The general acceptance of new technologies lies in both the value for money and the ease of use. “Our products lend themselves to be used to maximise labour-enhanced construction,” Murphy states. Applications range from simple road construction, using basic equipment (water cart, grader and compaction equipment) to sophisticated equipment using recyclers and/or central mixing plants. Due to the small particle sizes, these products are also very effective in penetrating and sealing existing old surfaced roads in combination with an ultraviolet-resistant modified emulsion. As a further plus, there is no pick-up by vehicles and no required repainting of road markings. A ‘clear hydrophobic seal’ is achieved via strong attachment to the materials comprising the old surfacings. The same effect could be achieved with the treatment of gravel road surfacings, preserving gravel coverings. The use of nano products is nothing new in the built environment. Nano technologies have been used to protect stone buildings for more than a century in Europe. The success of these treatments is closely associated with the type of stone (primary minerals) and the condition of the stone (weathering resulting in the formation of secondary minerals). In the new era, similar new-age products have been developed to protect concrete structures (commonly used in South Africa to protect bridge structures on roads), develop improved paints for the protection of buildings, etc.

Product and design services In addition to design expertise, GeoNano Technologies provides a range of solutions to achieve a successful end-product. GeNANO NME solutions ensure that naturally available materials can be utilised in any pavement layer, meeting engineering requirements in terms of stresses, strains and durability. The shelf-life stability (onsite) will be guaranteed for at least four months. However, stability in excess of


12 months has been proven without any detriment to the product quality. The NME is mixed with the construction water for ease of distribution in a process exactly simulating the compaction of a granular layer with the same control. No pre-heating of the NME is required. “GeNANO NME is not a ‘one size fits all’ solution. Adjustments to formulas are made based on the material, mineralogy analyses and the structural engineering requirements to be met,” says Murphy. GeNANO Prime Coat: This hydrophobised

nano emulsion is specifically designed to protect the stabilised NME layer against early damage, should the road be opened prior to surfacing. The GeNANO Prime Coat will also ensure that good bonding is achieved between the base and the surfacing. Drying time will occur within an hour. This product is also ideally suited for the protection of gravel on gravel roads. This is due to the high penetration achieved by using a grading of small particles for deep penetration, enabling strong material binding as well as protection against water damage. IMIESA October 2020



resistance to water damage. More can be achieved with available funds. • Environmental factors: the use of naturally available materials will largely eliminate the need for blasting of newly crushed stone, and the crushing, screening and long-haul transportation of materials. • Energy factors: the use of locally available natural materials requires less transportation and considerably less energy to achieve specified density requirements.

Concluding Remarks

GeNANO Clear Seal ‘Fog Spray’ is applied by watercart or hand sprayer. This product will achieve a high depth of penetration due to reduced particle sizes and provide prolonged protection against water damage (rendering the existing surface hydrophobic). Further advantages include quick drying, no contamination of vehicles and proven no reduction in skid resistance. The product design lends itself to being applied by hand sprayers (requiring little training) during maintenance activities. GeNANO Slurry Mix: A cold slurry-mix NME binder for the sealing of low-volume roads, this product can be mixed and distributed by hand or used in the production of a Cape seal.

SPECIALIST FIELDS OF EXPERTISE GeoNano's road and built environment solutions include: • Stone/gravel/soil stabilisation (NME technology) • Advanced anionic NME modified bitumen emulsion resins • Prime coats • Stone seals and pre-coating of stone for seals • Deep penetrative aggregate/gravel road seals • Fog sprays • Dust control • Labour-intensive cold slurry seals • Preventative maintenance solutions • Structural protective solutions • Capitalisation of mine waste material (e.g. coal dust, slags, slime and coal ash)


IMIESA October 2020

GeNANO CEMSEAL: This is a graded nanostructured solution that results in high (proven) penetration into any cement-based or concrete structure. This will render these structures hydrophobic and provide long-lasting protection against the detrimental effect of climatic influences and protect against chemical weathering. The ‘permanent’ bond effect of GeNANO CEMSEAL within the treated structure has a life expectancy in excess of 10 years.

“When we first started on this R&D road more than 16 years ago, many engineers were sceptical, made references to ‘snake oils’ and needed proof. They were 100% correct ‘you need scientific proof’. Our laboratory and field tests now provide a wealth of information from which to make informed decisions,” adds Murphy. “As we progress on our journey, GeoNano Technologies wishes to express its thanks to the engineers and academic mentors that have believed in our vision from inception and have shared our passion for innovation. Their selfless support has proved invaluable. NME technology is proven and the answer for Africa’s cash-strapped roads industry,” Murphy concludes.

Advantages The contribution of GeNANO to value engineering in the provision of sustainable infrastructure and the provision of basic road infrastructure can be summarised as follows in line with the concept of ‘green’ technologies: • Cost factors: The use of in-situ or naturally available materials saves on procurement and transport costs, without compromising quality, while increasing durability and


GeNANO Prime: A deep penetration Prime that provides superior binding of aggregates and renders the material hydrophobic. Depth of penetration up to 40 mm

Crash cushions are a lifesaver Managing a 385 km toll network, Bakwena is responsible for the N1N4 sections in Gauteng, North West and Limpopo provinces, the N1 from Pretoria to Bela-Bela, and the N4 from Pretoria to the Botswana border. André Wepener, traffic engineering manager, Bakwena, speaks to IMIESA about new safety systems being installed.


onitoring vehicle patterns and ensuring that optimal crash prevention measures are in place is a top priority for Bakwena. This dovetails with its ongoing asset management, maintenance and new construction programmes to ensure that road users enjoy a world-class experience. In terms of safety, Bakwena continues to research the best solutions from around the world and recently specified Lindsay Africa’s Tau TubeTM crash cushions at two sections of the N4. The first was installed at the Helen Joseph Interchange to provide impact protection at the approaching ends of new median concrete barriers. The installation of this Tau Tube system was carried out by Basella Maintenance. “These concrete barriers were installed to prevent illegal U-turns,” explains Wepener. “A key consideration was that the adopted solution to prevent the U-turns would not create an additional hazard to motorists. Investigations showed that concrete barriers were the most effective option. We then added the Tau Tube crash cushions to improve the safety of the installation.”

Designed for 110 km/h impacts Lindsay Africa fields a wide range of traffic safety systems. The Tau Tube range meets EN1317-3 specifications and caters for impact speeds of 50 km/h, 80 km/h, 100 km/h and 110 km/h. As Ivan van der Westhuizen from Lindsay Africa explains, the specification rating is for light to medium vehicles up to 1 500 kg.

The Tau Tube cushion installations for Bakwena are rated for a 110 km/h direct impact. The system also functions as a deflective barrier for side collisions. Composed of high-strength steel, each crash cushion is a freestanding structure anchored into position on a concrete base. Lindsay Africa supplies them as wide or parallel units. Lengths range from 2.7 m to 6.7 m, with widths from 850 mm to 2 430 mm – and installations can be permanent or temporary. The temporary installation can be used during road construction. When a head-on impact occurs, parts of the rail-mounted system are designed to slide back or concertina, absorbing and releasing the kinetic energy caused by the crash. Designed to be reusable, the cushion can subsequently be pulled back and restored to its original position by maintenance teams.

Bapong Traffic Control Centre “Safety and safety compliance are core priorities,” stresses Wepener. “And we took this into account during the construction of the Bapong Traffic Control Centre that operates 24 hours a day.” All approaching trucks are entering a screening lane and are weighed electronically in motion via pavement-embedded sensors – so called Weigh-in-Motion (WIM). When the WIM indicates that trucks are close to or exceed their legal load limit, they are required to enter the weighbridge to be measured statically, which is significantly more accurate and enforceable. For the approaching west- and east-bound screener lanes, wire rope crash barriers were installed to provide a barrier between higher-


Lindsay Africa’s new telescopic architecture is designed to absorb energy in a completely new way. The vehicle occupants in this collision survived without injury

A Tau Tube parallel crash cushion installed on one of the approaches to the Bapong Traffic Control Centre

speed light vehicles and the slower travelling trucks in the screener lane. Then, to complete the safety system, Tau Tube cushions were placed at both approaching ends, with this installation carried out by Emeka Civils “At Bakwena, we combine engineering interventions with strict traffic management control. Safety systems are designed to improve driver behaviour and to preferably prevent or minimise crashes. We’re aiming for zero loss of life and damage to our assets,” Wepener concludes.



Bakwena’s new 24-hour Bapong Traffic Control Centre

IMIESA October 2020



The treated road surface at AECI Much Asphalt Pietermaritzburg seven days after initial application without a maintenance spray application

Mine road in use after application, showing effective dust suppression

Fine dust particles not only affect workspaces and equipment in industries like construction, mining and manufacturing, but they also threaten the health and safety of workers, drivers, pedestrians and neighbouring communities.


Trial application in progress on a mine access road in Limpopo


ust par ticles 10 µm in size, known as respirable dust, are not visible to the naked eye and can cause serious harm by penetrating the lungs. Dust particles of 100 µm, which are visible and known as inhalable dust, can also lodge in the respiratory tract. Black lung, shortness of breath and respiratory failure are some of the irreversible health effects of ongoing exposure. Driving or operating equipment in dusty environments is also dangerous due to limited visibility. Dust suppression is achieved through the application of a liquid to prevent inhalable and respirable dust particles from becoming airborne. This generally involves a fine spray application of surface-active ingredients dissolved in water that bond to the airborne particles, weighting them to the ground.

New solution AECI SprayPave – a leading manufacturer, supplier and applicator of bituminous binders, emulsions, primes and pre-coats to the road construction industry – has used its


IMIESA October 2020

expertise in the bitumen field to formulate a waterproof binder known as Dustasolve-10. The product comprises a bitumen emulsion combined with nanotechnology additives. “Dustasolve-10 is designed to target dust on gravel roads, quarries and mines without the need for complicated layerworks equipment,” says Eddie Jansen van Vuuren, director, AECI SprayPave, pointing out that simplicity of application is key to the success of this product. “Dustasolve-10 can be applied with a bitumen distributor without the need for a roller. In typical warm South African conditions with base temperatures of 25˚C and rising, a road can be opened to traffic as soon as one hour after application.”

How it works Bitumen emulsion comprises varying volume fractions of bitumen droplets dispersed through an aqueous solution with the aid of an emulsifying surfactant. Bitumen emulsions can be easily applied at room temperature without heating equipment. However, Jansen van Vuuren warns that there are some shortcomings to be aware of


Trial water test in progress showing a lack of ingress into the applied dust suppression solution

Mine road surface a week after application

when it comes to dust suppression solutions. If the bitumen fraction is too high in the emulsion, it forms a layer that can sometimes become tacky, leading to lifting or movement under traffic. Another concern is the stability of the treated area in wet climates, when bitumen emulsion surface treatments that do not bond with the soil are washed away by rain. AECI SprayPave has addressed these concerns by incorporating bitumen additives with properties that enable the Dustasolve-10 particles to bond with the soil particles even at low bitumen volume fractions. This both reduces the inhalable and respirable dust

particles rising from unpaved roads and provides a strong waterproofing effect that mitigates water damage to the road surface. Spray applications can be between 1 ℓ/m2 and 3 ℓ/m2 depending on the surface conditions. Maintenance of the area may require reduced product application rates while achieving further dust control and improving road strength and protection. Depending on traffic on the surface, a maintenance spray may be required one to two weeks after the initial application. Dustasolve-10 has undergone trials at a mine in Limpopo and at three sites

of AECI SprayPave’s parent company, AECI Much Asphalt, in Benoni and Eikenhof, Gauteng, and Pietermaritzburg, KwaZulu-Natal. The trials have demonstrated the suitability of the product for dust suppression and helped to determine optimum application rates and respray maintenance requirements in different conditions. Jansen van Vuuren says trials to date have shown the new formulation to be quick penetrating, fast drying, non-tacky, waterproof, easy to apply and competitive in price.

Southern African Bitumen Association After 40 years Sabita continues to provide a valuable service to the roads industry, both local and international. Every success this Association enjoys is driven by member companies and other stakeholders equally dedicated in creating quality black top road in southern Africa. • • • • • •

Continued development of bituminous material technology Production of world class technical guidelines and manuals Transfer of technology & knowledge with global partners Promotion of sustainable health & safety practices Provision of quality training that meets industry requirements Engagement of stakeholders on all issues relevant to a sustainable road network.

5 Lonsdale Building Tel: +27 21 531 2718 Fax: +27 21 531 2606

Lonsdale Way



email: info@sabita.co.za website: www.sabita.co.za


Opening the way Founded in 1929, the Colas Group is a world leader in the construction and maintenance of transport infrastructure. Its roots in South Africa began to form in the 1930s and since then growth has been driven by a consistent focus on excellence, centred on an investment in human capital.


ransformation and gender equality remain a priority for the organisation. “While there have been many challenges facing the industry over the last few years, the Colas Group remains committed to participating in a better future for South Africa,” says Ricardo Louw, managing director, Colas South Africa. When Thuli Shabangu joined Colas South

Africa in 2017 as transformation and skills development manager, she embraced the opportunity to deliver on the company’s mandate to invest in and promote women and people from previously disadvantaged backgrounds. At the time, Colas South Africa was registered as a Level 4 BBBEE Contributor. “My responsibilities include mapping out and implementing an internal and external skills development plan, working with the group’s human resources managers,” Shabangu explains, adding that this ties in with the company’s corporate social investment initiatives. These have two key platforms, namely education and health. “We’ve also focused on supplier development, which includes assisting subcontractors with technical training.” Engineering bursary programmes are awarded to staff and qualifying external students currently registered at tertiary institutions. Adult basic education, management development programmes, and the mentorship of candidates through to registration with the Engineering Council of South Africa all form part of the mandate. Colas is also committed to creating opportunities for those with disabilities. “Internally, we encourage and empower our staff to believe in themselves and provide a supportive environment where everyone has an opportunity to grow. It gives me a great deal of satisfaction to see people thrive. Their passion and commitment are what make Colas such a great company to work for,” adds Shabangu, who is a registered Economic Empowerment Professional. The success of her programmes has been a major influencing factor in Colas’ current registration as a Level 1 BBBEE Contributor – a grading it has held for the past two years.

Technical excellence Those who join Colas experience an exciting and dynamic culture. For Nteseng Ramoraswi, who joined Colas as a technical manager in February 2020, it’s provided her with the opportunity to live her passion for chemistry. For her MSc, Ramoraswi’s

Nteseng Ramoraswi, technical manager

research focused on nano-photocatalytic materials, providing an excellent foundation for a career in asphalt. Colas’ track record for innovation is well proven and supported by the Campus for Science and Techniques, situated at the company’s global headquarters in Paris. “A key part of my work focuses on research and development (R&D),” says Ramoraswi. “It’s really exciting to be part of a dedicated team of scientists that analyse, test and produce fit-for-purpose bituminous binder products that provide safe and sustainable solutions for our road networks.” Colas’ R&D team works with leading roads agencies to perfect the mix designs. These include the widespread trend towards the use of recycled asphalt. “Based on our R&D studies and innovative solutions, we’re able to unlock value in reclaimed materials and add value by creating sustainable responses through recycling,” Ramoraswi continues. One of the current R&D projects she is involved in is a new bond coat product development. This has not yet reached the trial stage but has the potential to add real value for the roads industry. “If there’s one overriding aspect about Colas that excites me, I’d say it’s the tremendous diversity of experience and expertise. As a young scientist, I get to learn from the best,” adds Ramoraswi.

Thuli Shabangu, transformation and skills development manager

IMIESA October 2020


The leading roads contractor



ince its inception in early 2008, Roadspan has quickly become one of the leading road surfacing and rehabilitation contractors and asphalt suppliers in South Africa. The company boasts a comprehensive technical team and takes pride in its strong client relations and technical solutions. Heading up the Roadspan Group is MD Leutloileng Qhobela, who has been in civil construction for over 20 years. Mr. Qhobela, who joined WBHO in 2000, was seconded to head up Roadspan Surfaces in 2018. While it is no secret that the success of any team lies in the skills and experience of the

individual team members, one of Roadspan’s biggest strengths is its main shareholder. WBHO Construction has been the main shareholder and owner of Roadspan since March 2010. While retaining complete independence, Roadspan has, through this association, been able to leverage the proven systems that have been the success of WBHO over more than 25 years. The investment strategies of all shareholders are built around long-term returns and there is a universal commitment to growing Roadspan into a significant road surfacing and rehabilitation group. Roadspan Surfaces has surfacing teams dedicated to producing the best quality work as

required and specified by their various clients from the private and public sector. The decades of experience among the management teams on-site and in head office – together with the enthusiasm of the energetic teams out in the field – make for a professional and efficient combination. This includes wellmaintained, state-of-the-art equipment.


Tekfalt Binders can supply the full range of standard road pen bitumens as well as modified binders and bitumen-based emulsions and primes currently used in the road construc�on industry. With our flexible produc�on facility and in-house laboratory, the op�on can also be provided to produce customer-specific binders and emulsions to specifica�on. No. 24 Dolomiet Road Pendale Agricultural Holdings Randvaal, Gauteng

Telephone: +27 (0)10 003 2924

Email: sales@tekfalt.co.za

Website: www.tekfalt.co.za


What happened to the EPWP Infrastructure Sector? This definitive overview of the Expanded Public Works Programme (EPWP) during the 2004/05 to 2018/19 period highlights its failure to create sustainable employment and deliver infrastructure. By Robert McCutcheon


ithin South Africa, there are insistent demands for public infrastructure and housing. These demands for public services lie at the core of current community discontent. Communities are also demanding jobs in an environment where levels of unemployment are extremely high and disturbing. The narrow definition of unemployment, which is the one always reported in the media, tracks those who are actively seeking employment. For all South Africans, it is over 27%. The broad definition includes those who have given up looking; it is over 37% for all South Africans. In turn, disaggregation reveals far more disturbing results. For black South Africans, the figure stands at around 46%. The next worst affected group is the 16 to 35 age group, at 68%. Not surprisingly, employment creation is a national priority. And work is the means whereby we recreate ourselves and the world around

us. It provides an income and contributes to personal and communal dignity. However, another component of the dire situation in South Africa is the fact that employment opportunities need to be created for large numbers of people who have little or no education and very few formal skills. The lack of education and skills are largely the disastrous legacy of the 1951 Job Reservation Act and the iniquitous 1953 ‘Bantu’ Education Act.

Economic growth Economic growth is widely postulated as the solution. However, in the absence of adequate economic growth and low levels of education and skills, what is the solution? In South Africa, public works programmes are acknowledged as having a role to play. The 2011 National Development Plan recommended that public employment programmes would form a component of employment strategy until 2030. Labourintensive industries were to be encouraged.

SA’s Expanded Public Works Programme South Africa’s Expanded Public Works Programme (EPWP) is one of government’s strategic responses to the triple challenge of poverty, unemployment and inequality. The greater use of modern labour-intensive methods (LIC) was at the intellectual core of the EPWP. LIC is the technically sound and economically efficient substitution of human effort for non-essential, fuel-based, ‘heavy’ equipment. It generates a significant increase in productive employment among ‘targeted labour’1 : the poor, unemployed and unskilled. By ‘significant’, what is meant is an increase of at least 300% to 650% in employment generated, without compromising

on cost, time and quality (once systems, including training, have been established). The range varies for different categories of construction. ‘Earthworks’ provide the main opportunity for this substitution. Earthworks comprise over 50% of the cost of most civil infrastructure projects: excavation, haul, unload and spread. Think ‘lots of small earthworks’, not ‘mass earthworks’. Legislation, regulations and procedures were introduced to promote LIC. However, LIC still hasn’t gained the traction it was meant to. A review of the available data confirms this. During the 15-year period between April 2004 and March 2019, the EPWP was allocated R1 540 153 million.2 Of this amount, some R1 149 835 million was apportioned to the Infrastructure Sector. In the end though, a total amount of R253 741 million was spent – of which the EPWP Infrastructure Sector component only came to R179 229 million. The degree of discrepancy between allocation and expenditure vividly illustrates the public sector’s well-known lack of capacity to deliver at national, provincial and local levels.3 However, overemphasis upon pervasive incapacity within the public sector shouldn’t distract us from manifold shortcomings in the implementation of the EPWP’s Infrastructure Sector itself. Between 2004 and 2019, expenditure on infrastructure generated over 1 260 000 person-years of employment.4 This is far less than should have been achieved. The large expenditure of public funds should have generated a huge increase in productive employment for the poor and unskilled – together with the concomitant, essential skills development (mainly for matriculants) required to organise and control on-site construction and maintenance.

IMIESA October 2020



Key deficiencies The author provides argument and evidence to substantiate the following critique. In the first instance, the EPWP’s Infrastructure Sector is a programme in name only. It has failed to establish any sort of construction programme in the sense of a series of planned projects constructed using LIC. In fact, it continues to be an ad-hoc collection of disparate, individual projects funded mainly by the MIG and simply labelled a programme. A cornerstone of LIC is that payment should only be made on completion of set individual or group tasks. A competent, trained supervisor5 sets the task; however, the fundamental importance of output-based remuneration for this type of project has been ignored. Paying a daily wage without any link to productivity has undermined the cornerstone. The remnants of this cornerstone were destroyed in March 2020 by the official decision to pay an hourly minimum, without any reference to production. It was mandatory to construct particular categories of infrastructure labour-intensively: low-volume roads, stormwater drainage, sidewalks and trenches. The mandatory conditions for the expenditure of funds on the LIC construction and maintenance of these particular categories of infrastructure have neither been obeyed nor enforced. The original mandatory requirement relating to competence of the consulting engineers entrusted with EPWP/LIC projects has led to NQF 5 and 7 requirements in tenders. The EPWP has claimed that numbers of people have been trained. The unimpressive results demonstrate that this training has not resulted in LIC. Furthermore, analysis revealed that the totals paid for professional fees and wages were not very different from one another. This is a travesty. Expenditure on wages should far outweigh professional fees. Essentially, an elaborate, ineffective process has led


IMIESA October 2020

South Africa’s EPWP is one of government’s strategic responses to the triple challenge of poverty, unemployment and inequality to an enormous waste in time, effort and expenditure. The physical quantity of assets has not been recorded in the monitoring and evaluation (M&E) system. It is therefore impossible to assess the value obtained for the expenditure of funds and human effort. Neither can one facilitate an offset of the value of assets created against an expenditure, which is currently assumed to be payment to labour. Furthermore, there is still no linked programme of training and construction for the full NQF 4 level qualification of ‘hands-on’ construction processes site supervisors.

A new approach required In relation to expenditure on public infrastructure, the author recommends disentangling LIC from the complex, cumbersome and now outmoded MIG and PIG regulations and procedures that have failed to promote it. The web of confusion and contradiction and the inappropriate M&E system must also be removed from association with the provision of public infrastructure, particularly small-scale municipal-type infrastructure. A new approach is required – or rather, a re-evaluation of an approach that relied on the contract for greater use of LIC. The basis would be the Framework Agreement between Cosatu and the Construction Industry in 1993, which was incorporated into the National Public Works Programme in 1994. As an industry, we need to unashamedly maximise the efficient use of LIC for the

construction and maintenance of public infrastructure. We need to forbid the use of non-essential fuel-based heavy equipment for those mandatory categories of construction, namely low-volume roads, stormwater drainage, sidewalks and trenches. Technical progress since 1994 means that more mandatory categories could be included. We shouldn’t use ‘cop out’ clauses like ‘wherever feasible’ or meaningless, feeble terms such as ‘labour-friendly’ or ‘labour-enhanced’.

Task-based work is essential In principle, ‘A fair day’s wage for a fair day’s work’ makes sense. However, in LIC, wage payment must be dependent upon the completion of a set ‘task’. Trained supervisors and the use of ‘output based remuneration’ would ensure ‘a fair day’s work for a fair day’s wage’. As expressed in the Code of Good Practice for Employment and Conditions of Work for Special Public Works Programmes: “A ‘no work – no pay’ rule must apply except in the following circumstances: illness… injury”. We also need to review the wage paid per task assessed against an accepted output of effort. The wage per task would be considerably more than that paid on the EPWP’s Community Work Programme (which is yet another source of confusion at the local level). A review of the wage scale should be considered alongside the statutory construction sector wage rates agreed annually. Another recommendation is the reinstatement of the original rule that “works identified to be undertaken by LIC must be constructed through that method”. Failure to do so must be enforced by the client’s refusal to pay for works performed incorrectly according to the contract. This would be simpler to enforce than the current situation, where no one knows for sure whether LIC is being used correctly.


The Department of Public Works and Infrastructure should review the Ministerial Determination and DORA in accordance with this new vigorous approach. The Attorney General would have to give full support through rigorous enforcement of conditions of contract. A truly independent body, independent of the EPWP, should be appointed to visit all LIC sites and have the authority to enforce the legislation and regulations. Furthermore, the scale of professional fees and the overheads must be in line with the principle that experienced consultants should be appointed for ‘large’ contracts. They should be required to transfer their experience to others, either by free transfer or by partnering. The concept of the consultants ‘learning on the job’ – at the expense of the project – must be eliminated. A new M&E system is essential. In the first place, quantities must be recorded. In the second, end results should be

based upon the amount of infrastructure constructed according to a specific number of person-years of human effort. To address the lack of progress to date on proper technical training, the author would advocate that municipalities and SOEs like Sanral establish ‘in-house’ linked programmes. These would formally link construction and maintenance to the training of ‘hands-on’ single-site supervisors holding the NQF 4: Construction Processes Site Supervisors qualification. Critical for the execution of results-based outcomes, more independent and entrepreneurially minded supervisors could also receive supplementary training and become small contractors. Going forward, Covid-19 has placed even greater pressure on South Africa’s fragile economy, with unemployment now rising to unprecedented levels. LIC and EPWP infrastructure investment are part

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of the solution. As an industry, we need to work together to ensure alignment and implementation. *Robert McCutcheon is a professor emeritus and honorary professor at the University of the Witwatersrand’s School of Civil and Environmental Engineering.

'Targeted labour’: local people whose human effort is replacing fuel-based heavy equipment. It does not include those who would have been employed during conventional equipmentbased construction (traffic control, security, cleaners, etc.). 2 In the period 2004 to 2019, the value of the rand fluctuated between R5.50 and R15.00 to the US dollar. 3 Although there has been a severe inability to spend the allocated budget, the allocations indicate the scale of internal resources (ostensibly) available to South Africa. 4 In EPWP language, one ‘full-time equivalent’ is equal to 230 days per year. 5 NQF 4 level – the supervisor could be a contractor. 1


BIM’s potential untapped New technology is ushering in significant changes. IMIESA speaks to Tijs van den Brink, advisory group director: Digital Services, Royal HaskoningDHV, about how recent developments like building information modelling (BIM) are changing the game. How are technology and new developments changing the way industry works? TvdB Information is the key enabler to make anything more efficient. Technologies such as the internet of things (IoT), artificial intelligence (AI), drones, laser scanning, etc. enable us to collect masses of data in a very short time. This data can be increasingly processed at high speeds, assisting us in making informed decisions. Coupled with highbandwidth internet and largevolume data storage, access to the relevant information is available faster and virtually anywhere in the world. Emerging technologies have already had a massive impact in the construction industry. It is transforming everything, from sending drones to inspect and map areas that are unsafe for humans, to 3D printing materials to save time and costs, to using IoT to monitor machines and


IMIESA October 2020

predict downtime before it happens. Now, it’s advancing even faster, with new applications and opportunities arising that we’ve yet to consider the impact of – things like autonomous heavy equipment and using AI to scan construction sites to assess the quality and progress of work in real time.

What are the benefits of BIM for infrastructure projects? With more and more data being gathered on construction projects, it is important to standardise the way we collect, store, process and transmit that data. BIM provides us with such a standardised process, while ensuring the availability of the latest information to all interested parties. BIM is a process for creating and managing information on a construction project across the project life cycle. The name falsely suggests it just applies to

buildings – it actually applies to standardisation in the entire built environment. It’s why we sometimes prefer to call it better information management. BIM as a process enables us to make the right decisions at the right time. In gathering data from all stakeholders involved on a project (including clients, engineers, architects, construction teams and contractors) and storing it in one place – the model – the entire team is on the same page – from concept, to construction, future operations, maintenance and renovation. In the model, we create a single source of the truth. Then, BIM software brings all this information to life in a visually engaging and interactive way. It’s not only a 3D representation of how a building will look and feel once it’s constructed, but it also gives insights into its inner workings. This enables the project team to test different scenarios and resources before construction starts – like a dress rehearsal before the big show. The benefit of this is that things happen faster, more efficiently, and more accurately. Beyond efficiency, an additional benefit of adopting BIM and working with a single version of the truth is traceability – it is a very, very transparent process.

With BIM, even before starting work on-site, the project team can test different layouts and construction techniques, avoid incompatible designs and spatial clashes, identify structural problems, improve the facility’s carbon footprint, and enhance on-site safety, for example. The challenge with adopting BIM, and we see this currently, is that it requires a bit of investment in learning and mastering the process, the standards and tooling available. This is a deterrent for some of the parties involved, but there are some school fees to be paid to unlock the cost savings unlocked by managing information better – across the life cycle of the asset.

Is government likely to insist on the use of BIM for public projects in the future? The value in BIM is in standardisation, and government has a crucial role to play there. If not standardised in South Africa, BIM could be just another way of working. We trust governments will see the benefits of cost saving and transparency and will follow the lead of the UK, Singapore, UAE and Scandinavian countries, insisting on its use in the future.


This will help public buildings and infrastructure become more affordable and sustainable, as well as help project delivery to become safer and more predictable. This also requires our contracts to be aligned with BIM, and clear guidance on ownership of the information for example. In the meantime, however, the industry is moving forward rapidly to unlock the benefits. The push for standardisation is strong, both through standards

Technology and software have come a long way, lowering the barrier to adoption in South Africa and enabling us to leapfrog.” developed by the International Standards Organization (ISO), for example, as well as open standards and open file formats, enabling interoperability and vendor-neutral processes to ensure accessibility, usability, management and sustainability of digital data.

We’re involved in these global developments and make sure our teams are trained to be on top of the latest developments, taking our clients and partners with us on the journey.

Is BIM being used to its full potential in South Africa? Not yet, but South Africa is not alone in this regard. We need to be aware of the difference in maturity levels between the stakeholders. Using BIM to its full potential simultaneously requires government to push for the development and adoption of processes and standards as well as stakeholders in the current supply chain to upskill. New talent entering organisations should be prepared through futureproofing (university) curricula by embedding BIM (both the processes as well as training on software packages). Technology and software have come a long way, lowering the barrier to adoption in South Africa and enabling us to

leapfrog in this regard. The industry as a whole is maturing. In the past, the focus was on the 3D design aspect, treating BIM adoption as the mastering of a software tool to (coordinate) design with BIM use, getting lower during construction and even lower during operations and maintenance of the asset. The focus is increasingly on information (as opposed to just 3D visualisation), increasingly unlocking the benefits. The untapped potential benefits are vast, as the standardised information models can be carried through beyond design and construction to enable efficient operations and smarter management of the asset. This operations phase spans the longest period of the built asset’s life and offers great potential for the efficiencies and cost savings brought by BIM. Another application would be to fill the void of missing as-built information by point cloud scanning existing assets to extract a 3D image of the object, followed by reverse

engineering the physical and functional aspects of the BIM model, precisely reflecting its current state.

Where can we improve moving forward? We’ve already outlined the roles of governments and universities, but it is important for the private sector to start implementing BIM wherever possible, learning from our mistakes and familiarising ourselves with the process and standards. For the industry to grow, it is important for companies that are already familiar with BIM and available tooling to involve clients and partner companies/ subconsultants in the process and software. The successful adoption of BIM requires a high level of collaboration among stakeholders. It is up to the front runners locally to help others throughout the supply chain develop. This includes training clients, consultant partners and contractors on how to use the standards and available tooling, to maximise the benefits.

IMIESA October 2020



Circular tank developments

Developed by Structa Technology’s engineering team, the new Circotank range draws on vast experience gained in the design of industrial and petrochemical storage vessels and tanks.


Midi tanks designed for small to medium storage requirements

Easy top first segment assembly on a Maxi tank


IMIESA October 2020

he introduction of the Circotank series meets the growing demand for practical water storage solutions across a diverse user spectrum that includes commercial and industrial clients, agriculture, rural and peri-urban communities. Manufactured from galvanised steel sheet cold-rolled with a stiffening profile, each tank comes equipped with a replaceable PVC liner for extended durability and reliability. Ease of shipment and installation is a further key feature of


The Maxi range caters for storage requirements ranging from 100 000 up to 1.5 million litres

Structa’s R&D team interrogated the Circotank’s design using finite element analysis techniques to check for collapse and other failure modes

A Midi tank mounted on its integrated stand

these modular tanks, which are designed to be transported to the remotest sites in pre-rolled segments. Supported on a cast in situ concrete ring beam foundation, the tank is then erected using a simple strake lifting system, with full installation ser vices provided by Structa’s specially trained teams.

Made to last During research and development, Structa interrogated the Circotank’s design using finite element analysis techniques to check for collapse and other failure modes. Materials and joints were also thoroughly tested during the development phase to confirm overall durability, quality and reliability.

the Maxi and the Midi. The Maxi range caters for large-scale water storage projects ranging from 100 000 up to 1.5 million litres. Typical applications here include industrial water storage, fire-fighting and potable bulk water supply schemes. The Midi range is targeted at small to medium installations and fills a gap not covered by typical moulded plastic tanks. End-users encompass schools, clinics and small rural communities. Midi storage capacities range from 5 000 to 20 000 litres and work optimally when placed on stands to provide distribution pressure. Both the tank and stand are supplied as an integrated system.

Local manufacture Midi and Maxi Two product lines are fielded, namely

South Africa

The Circotank range is manufactured at Structa Technology’s Meyerton factor y in

Gauteng, where the equipment used for the semi-automatic punching and profiling were custom developed. In-built flexibility within the industrial engineering process provides the capability needed to custombuild Midi or Maxi tanks according to the client’s requirements and conforming to Structa’s ISO 9001 quality system. It is said the best inventions are the simplest. In Circotank’s case, that translates into an exceptional return on investment in terms of the total cost per cubic metre of water stored.


Mammoth culverts set new record


hen the City of Tshwane required 3 m x 3 m custom-made jacking box culver ts for a service delivery project at Iscor Heights, Pretoria West, Rocla found an out-of-the-box solution. The culverts were manufactured with an in-the-wall joint that can be sealed with a rubber ring if required. The project required 90 large-sized culverts to create two 50 m long underroad tunnels, 6 m below the road sur face, in order to provide new water ser vices to the area. “We have worked with Rocla on various projects over the years, so we knew that these large jacking culverts would have to be specifically designed and manufactured, and that Rocla was the only company that had that kind of creative capability,”

The project required 90 large-sized culverts to create two 50 m long under-road tunnels, 6 m below the road surface, in order to provide new water services to the area


IMIESA October 2020

Rocla’s 3 m x 3 m custom-made jacking box culverts are the largest of their kind to be manufactured by the company

comments Len Nel, contracts director, Esor Construction. The largest jacking pipe Rocla had manufactured in the past measured 3 000 mm x 2 500 mm, which was too small for the project. “After many meetings to discuss the design and verify the technical requirements of the jacking culverts to ensure that the final product would meet the loading requirements, the final culvert weighed in at an excess of 10 t per product – a major design and manufacturing coup for Rocla,” Nel adds. The timeframe from approved product specification and design to mould completion was only 16 weeks for the 90 culverts. Due to the enormous size of the culverts, the deliver y to site required an abnormal load permit and they were

offloaded into the pit at site with a side boom crane. “Rocla is extremely proud to have been involved with this unique project. It tested our design team’s expertise and our manufacturing processes to the limit, but showed that no project is too big for Rocla to collaborate on. It will certainly become one of Rocla’s historical milestones,” says Brendan van Vuuren, sales representative, Rocla. Rocla forms part of the Infrastructure Specialist Group, which also includes Technicrete. Rocla manufactures various culvert designs and culvert base slabs, along with stormwater pipes and other infrastructure products such as HDPE and pressure lined sewage pipes, concrete poles, manholes, bus shelters, sanitation units, and concrete cabins.


Sandton’s smart surveillance solution

A newly launched closedcircuit television (CCTV) system is using state-of-the-art artificial intelligence to make Sandton Central better and safer by detecting and responding to specific events.


he launch of the CCTV system by the Sandton Central Management District (SCMD) follows a threemonth pilot to test its 111 cameras covering Sandton Central’s public spaces and transport network in order to maintain safety and security and prevent crime. When an incident is spotted, it sends an alert to a central control room where a real-time video feed enables control staff to take the best action. This could mean reporting broken infrastructure, alerting the emergency services to an accident, or calling law enforcement to an incident. The system can spot broken traffic lights, visible water leaks, and cable thefts. It can also accurately identify stolen vehicles and those suspected of having been used in the commission of a crime. “This innovation is a key private sector contribution to a smart city solution for Johannesburg. We cannot ignore the benefits of technology in urban management and safety. Our partnership is open to the city, and our new CCTV system also provides the opportunity for even more collaboration by being open to and compatible with new plug-ins,” says Elaine Jack, district improvement manager, SCMD.

Partnering for success The system comprises three main elements: the camera feed, surveillance monitoring, and response. Vumacam is responsible for installing and powering the cameras and connecting the CCTV surveillance infrastructure to the monitoring centre. AI Surveillance (AIS) is responsible for the surveillance monitoring. It uses different programs – from number plate recognition to software that detects specific behaviour patterns and anomalies – and applications that track and analyse traffic flows. The software creates visual alerts for the control room where the situation is viewed and assessed, and the right response is put into action. Sandton Central is one of several Gauteng city improvement districts monitored from the AIS central control room and, as a result, benefits from shared intelligence and collaboration. Depending on the nature of the incident, either Servest’s Sandton Central safety ambassadors or the tactical response of Night Guard Security will respond. Both teams have a constant presence and vehicles in Sandton Central. Jack also stressed the importance of SCMD’s partnerships with the SAPS and JMPD. “Leading cities across the world use this kind of technology to respond to major events and situations in real time, making policing and investigations more effective. The SAPS, JMPD and emergency services can now be assured that Sandton Central is correctly summoning them to the incidents that

require their specialist service and supporting their case investigations with quality video surveillance footage to enable crime intelligence.” The CCTV cameras only capture information relevant to law enforcement investigations and only those who are legally authorised can view footage. Strict measures are in place to ensure privacy in line with the Protection of Personal Information Act (No. 4 of 2013) and other regulations. Scott Thorburn, chairperson of the Sandton Central Operations Committee and the Sandton Business Improvement District, remarks, “This project represents a massive amount of time, effort and input from a wide range of stakeholders and specialists. We are confident it provides a solid, but flexible, foundation from which to improve urban management, safety and crime intelligence in Sandton Central. The powerful combination of technology and human skill will create a safer neighbourhood with less disruption.”

Elaine Jack, district improvement manager, Sandton Central

IMIESA October 2020



How technology will reshape South Africa

The socio-economic impacts of Covid-19 have fast-tracked the world’s transition through and possibly beyond what has been referred to as the Fourth Industrial Revolution (4IR). Alastair Currie speaks to Lebo Leshabane, CEO, iX Engineers, about the implications for South – it’s a working African construction.

Has Covid-19 presented new ways to work smarter? LL Covid-19 took the world by surprise and the sweeping impacts were so rapid that everyone initially assumed a defensive, reactive mode. It felt like we had to start living a new life instantly. That clearly forced us as a business to rethink and re-strategise. Some eight months later, we have come through the worst of the pandemic storm. But what’s next? It’s clear that we need to accelerate the evolution of our operational models to respond to a new way of working. 4IR is no longer an academic and futuristic discussion

reality. The future is here, and we need to invest in and adopt the latest 4IR skills and technologies now. That includes ongoing IT investments so that we can manage, model and analyse the massive surge in data volumes. Our clients are now also reviewing their models and processes, recognising the opportunities to strip out inefficiencies within their processes. If we all make the change together, that will lead to far greater efficiencies in terms of funding and infrastructure execution. This is crucial for the revitalisation of our construction sector.

How are the traditional services that consulting engineers offer evolving? I see technology playing a bigger role in the design phases of a project. If anything, technology enhances rather than replaces our engineering skills. For example, the conceptual design for a project cannot be done by

Lebo Leshabane, CEO, iX Engineers


IMIESA October 2020

a robot. You still need a human to conceptualise the solution to specific challenges. That’s the core skill of an engineer. Once you shift to the preliminary detailed design stages, though, these processes will increasingly be automated via artificial intelligence (AI) platforms. The upside is that this provides more opportunities for the human engineer to interrogate and test the solution, making sure it works in practice. In future, engineers and machines will collaborate to achieve the best result. That includes the use of virtual and augmented reality to simulate a real-world experience. Within the construction space, design, project and programme management will also be strongly influenced by new build technologies, like 3D printing.

Is AI a threat or an opportunity? AI will increasingly become a part of every industry and every facet of our lives. It’s a powerful tool, so let’s embrace it and harness

the benefits. An example is the adoption of AI traffic management systems. AI further provides tremendous scope for diagnostics and troubleshooting as we shift to a data-driven society. There are also great opportunities to enhance automation via AI interfaces in areas like water and wastewater process engineering, and optimum bulk water supply. Climate change is a real threat and urgent responses are needed to ensure we don’t pass the point of no return. This will chiefly depend on intelligent engineering interventions using AI to model scenarios.

How practical are smart cities for the South African market? Africa has the greatest


opportunity to implement smart city concepts, given its intensified urbanisation and population growth. Africa also presents huge opportunities for greenfield developments. Within South Africa, I think a hybrid approach works best. We need to remodel our historic cities – like Cape Town, Durban, Johannesburg and Pretoria – to create more liveable, open spaces centred around industrialised hubs and leveraging off our existing infrastructure. One thing the Covid-19 lockdown emphasised is the oppressive nature of historically over-densified human settlement models. Alexandra township in Sandton being a case in point. Revisiting spatial planning models can unlock the value from currently underutilised land in and around our cities. We need to shift informal to formal and create integrated

communities that include rather than exclude. We also need to embrace alternative building technologies (ABTs) that are energy efficient and use recyclable materials that stimulate the circular economy. ABTs provide the speed and cost efficiencies we need to build just about any type of development – from a school to a hospital, warehouse or home. There’s no question that ABTs can help us quickly close the housing backlog gap. Smart cities need smart technologies and the faster we can incorporate them into our infrastructure planning, the better. As the public-private partnership (PPP) model gains more traction, fresh funding will help to drive this.

Which sectors are you focusing on at present? We are active across the full infrastructure spectrum. This includes work for Sanral and roads departments. Water and sanitation are also core sectors, a recent example being a large pump station refurbishment for Rand Water, a turnkey contract completed in conjunction with King Civils. We anticipate that the water and sanitation market will grow significantly from 2021, spurred on by potential PPP investments. Alongside this, we are expanding our electrical engineering capabilities to tap into a wide range of energy projects for both distribution

and transmission. This includes power generation and storage. For large power users like the mining sector, we design longlasting storage systems based on the kinetic battery model. Within the renewables market, the untapped potential is enormous, and we are actively expanding this niche. Recently completed projects include a wind farm in Spain, where iX Engineers was responsible for the foundation design. This follows the successful completion of a similar project for the same developer in the Eastern Cape, South Africa. Current work includes a gasto-energy project for a client in Rwanda, which will serve as an excellent showcase of our capabilities. Within South Africa, we’re working with clients on various gas-to-energy proposals, some in response to opportunities presented by the Department of Mineral Resources and Energy’s Independent Power Producer Procurement Programme.

Where can you assist municipalities to be more sustainable? As consulting engineers, we have extensive expertise in effecting systems and solutions. The advent of 4IR now provides additional tools and capabilities. Aside from grant funding, the bulk of the revenue needed to run and sustain a municipality is sourced from

key billable services like water and electricity. However, most municipalities are under increasing financial pressure as revenue streams shrink due to a combination of factors. These include consumer non-payment and illegal connections, compounded by poorly maintained or failed infrastructure – an example being South Africa’s national non-revenue water losses, which are presently estimated at around 50%. As a starting point, it’s vital that every municipality has an up-to-date asset register and that maintenance budgets are correctly allocated. We assist with this process, as well as in implementing predictive and preventative maintenance planning. Aligned to this is an investment in the right technologies. We encourage our clients to switch to intelligent assets that can be monitored in near real time.

Where to from here? In addition to our traditional design capabilities, we are increasingly focused on implementing turnkey solutions in response to market demand. We are also committed to being at the forefront of 4IR technologies that enable us to design, execute and manage projects more cost-effectively. South Africa’s post-Covid-19 socio-economic recovery depends on a strong and vibrant construction sector.

eT H E K W I N I



Catalytic investments 35

Supporting water and food security 41

Giving back 37

Incentivising a catalytic development 43

TSAM supports the fight

Building Durban Point Promenade 45

against Covid-19 39

Durban leads in climate action 47

IMIESA October 2020


Catalytic investments The City of Durban’s Western Corridor forms an important part of the economic development and growth plan for the city, the province, and the country. IMIESA speaks to Tshepiso Kobile, senior programme manager: Catalytic Projects Unit, eThekwini Municipality, about catalytic developments along the Western Corridor.


he city’s Western Corridor, which centres around the N3 towards Johannesburg, forms an integral part of the national distribution network from the Port of Durban – the busiest shipping terminal in sub-Saharan Africa. As such, the corridor is incredibly impor tant for increasing economic activity and unlocking accessible job creation, while also diversifying the income generated by the city from property development activities. There are currently three catalytic projects under development along the Western Corridor: the Ntshongweni Urban Development, Cato Ridge Freight and Logistics Hub (Dr y Port), and Keystone Park. Kobile notes that catalytic projects are large-scale integrated and mixed-use projects that are generally implemented through partnerships between government and the private sector. “As a city, we see such projects as catalysts for economic growth and significant promotion of social inclusion through spatial transformation. With an investment value of billions of rand, they normally require major bulk infrastructure and funding from a number of sources. Considering that they are implemented in collaboration with others, they have thus been categorised as private sector led (Categor y A) and public sector led (Categor y B),” says Kobile. She further explains that the city has established a Catalytic Projects Unit, with the primar y role of providing the following functions: • a one-stop shop, providing a single entr y point for private sector led development projects to: - facilitate processing of development

rights applications within shorter turnaround times - facilitate internal departmental contribution/support to private development - facilitate resolution of challenges and/ or disputes between departments and developers • project manage, implement and coordinate the implementation of catalytic land development projects across the city

• influence pipelining and coordination of land development and bulk infrastructure capital investment roll-out plan.

Ntshongweni Urban Development The Ntshongweni Urban Development is a 2 000 ha integrated mixed-use development – twice the size of Cornubia – which will be developed in a phased manner. Located 14 km from the Pinetown CBD and Hammarsdale, the project is currently at an advanced planning stage.

Artist impression: Mall of The West


Artist impression: Ntshongweni Urban Development

• 500 000 m² commercial space, including 65 000 m² retail space (Phase 1 of mall) • 20 000 residential homes catering for mixed income groups • 1 000 ha of open space and recreation • 1 000 ha of logistics zoning • 10 000 construction jobs and 2 000 sustainable jobs to be created during Phase 1

IMIESA October 2020


ETHEKWINI Cato Ridge Freight and Logistics Hub

CATO RIDGE LOGISTICS HUB COMMUNITY BENEFITS • 2 000 job opportunities during construction and 6 000 on completion of Phase 1 • Education and skills development • Entrepreneurial upliftment • BBBEE ownership structure with community interest • Port decongestion • Promoting a shift from road to rail

According to Kobile, the land borders the growing, higher-income Hillcrest community on one side and a vast semi-rural and marginalised hinterland on the other. The development therefore aims to integrate the two communities. With an investment value of R8 billion, Phase 1 of the development, known as the Urban Core, is anchored by a regional shopping centre expected to be completed in 2023. The overall development comprises a balance of mixed uses, including office, light industrial, logistics and business parks, open spaces, and mixed-typology residential that caters for various income groups. The infill development, led by Tongaat Hulett Property, is envisaged to eventually reshape and revitalise Durban’s Outer West by creating an entirely new economic hub in the area.

integrated freight and logistics solution that will improve the efficiency of movement of goods between the Port of Durban, the inland industrial centres of South Africa, and across borders within the SADC region. “This is important in the context of the port being fully surrounded by urban development with no room for expansion, and a back of port area that is consequently congested,” explains Kobile. Cargo from the port will be transported via rail to the intermodal facility Malda Pack Facility at Keystone Park

Cato Ridge Logistics Hub Located just a few kilometres west of Ntshongweni, the Cato Dr y Port is recognised as a catalytic project across both local and provincial spheres of government, and a critical part of the national SIP 2 programme. The project’s fundamental objective is to deliver an

SPOTLIGHT: KEYSTONE PARK • 1 000 000 m² of fully serviced, platformed land • 100 000 m² under-roof national distribution facility • 3 000 job opportunities created to date • 200 learnerships to date


IMIESA October 2020

Ackermans Facility at Keystone Park

in Cato Ridge, where it will subsequently be transferred on to the road network and transported to its inland destination. With an investment value of more than R10 billion, the Dr y Port will consist of: • a truck stop and staging facility to stage road trucks and ensure free-flowing traffic in and out of the Cato Ridge development and the Port of Durban • an inland port to handle and store containerised and automotive cargo


• a logistics and industrial park to provide tenant facility for cargo distribution centres, as well as cargo consolidation and de-consolidation, while also offering space for light manufacturing activities • a tank farm where petroleum products can be stored. Construction of the first phase, including the railyard and truck stop and staging facility, is scheduled for completion in 2021, followed by the container terminal and logistics park in 2022. Transnet already has a pilot rail terminal at Cato Ridge, which will be expanded to increase capacity.

Keystone Park Keystone Park is a 152 ha logistics, warehousing and light industrial precinct located just off the Hammarsdale Interchange. The most advanced of the three catalytic projects, Keystone Park already has end-users operating from some of the sites, including Ackermans, Bakers, Mr Price, Illovo, Unilever, Value Logistics and Massmart. The intention is to position Keystone Park as the best functioning, modern, fully ser viced, secure

and managed logistic park in KwaZuluNatal. Located only a few kilometres away from the Cato Ridge Dr y Port, the park provides easy access to the Durban, Pietermaritzburg and Johannesburg main transport routes. Land development is estimated for completion in 2023, with around 70% of the R6.5 billion development already committed or sold. “With the Port of Durban handling large amounts of cargo – mainly imported goods moved by road – ser vicing the market from Keystone, Cato Ridge and future logistics phases of Ntshongweni will enhance efficiencies and yield savings in both inbound and outbound transport costs to end customers,” says Kobile.

Infrastructure development requirements According to Kobile, the bulk infrastructure requirements for these projects present one of the biggest challenges, as some of the infrastructure (particularly road infrastructure) falls within the mandates of national, provincial and local spheres of government.

Because the projects are greenfield developments in an area that has historically not seen large investment in infrastructure, despite increasing market demand and activity in recent years, bulk infrastructure in the form of roads, electricity, water and sewers will be required in a phased manner. Critical bulk road infrastructure will include the upgrading of Kassier Road and Hammarsdale P385, upgrading of the Cato Ridge Interchange and construction of the new KwaXimba Interchange. “Ver tical integration and transversal management are critical to the successful implementation of these developments. This is being effected through the structuring of mutually beneficial par tnership models and the use of quite comprehensive institutional structures where the municipality, private sector developer, communities and other infrastructure authorities can be represented and have a platform for collaboration to address blockages on the projects,” concludes Kobile.




series of donations made by representatives from IMESA’s KwaZulu-Natal Branch have helped to alleviate repercussions of the Covid-19 lockdown. “As municipal engineers, technologists and technicians, IMESA’s members work within and for the community when it comes to infrastructure service delivery,” says Geoff Tooley, operations director, IMESA. “We therefore see first-hand how the Covid-19 pandemic has impacted on the poorer and more vulnerable members of our society.” The first of two recent donations made by

IMESA KwaZulu-Natal Branch handing over donations at St Peter’s Church. L-R: Father Georges Bidzogo, St Peter’s Church; Geoff Tooley, operations director, IMESA; and Dave Wilson, branch committee member, IMESA

the IMESA branch was a delivery of foods to St Peter’s Church in Mahatma Gandhi (Point) Road in Durban, where food parcels were packed for distribution to those in need. The second donation was a delivery of food and blankets to the Durban & Coast SPCA in Springfield Park for the animals housed at that shelter. “When government, the private sector and civil society come together to find proactive solutions in a crisis, this serves as a catalyst for a positive and permanent mindset shift. As IMESA, we remain committed to supporting sustainable interventions,” adds Tooley.

IMIESA October 2020


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TSAM supports the fight against Covid-19 Continuing the fight against the spread of Covid-19, Toyota South Africa Motors (TSAM) has signed a memorandum of agreement (MOA), which includes a multimillion-rand support package, with the KwaZulu-Natal Department of Health (KZN DoH), as well as eThekwini Metropolitan Municipality.


he MOA outlines Toyota’s pledge of close to R15 million to provide Covid-19 testing equipment, hospital facility support, 10 Hilux models for contact tracing, as well as 50 000 face shields in the region. The project is funded entirely by TSAM – except for the capital raised for testing equipment, where Toyota business partners made some meaningful contributions – and was launched under the organisation’s corporate social responsibility (CSR) banner called ToyotaReach. The testing equipment will be installed at a testing centre that, once operational, will be capable of processing up to 5 000 additional samples per day. The facility as well as the human resources needed to operate it will be provided by eThekwini Municipality. “The reality is that this disease is not going to miraculously disappear; we want to prevent a flare-up or second-wave spike, which has been the experience in many other countries ,” says Andrew Kirby, President and CEO of TSAM. As the leading auto manufacturer in the region, Kirby believes it fitting for the ToyotaReach programme to expand its scope of involvement to enable access to remote areas. “The KZN DoH identified a dire need to conduct contact tracing and testing in rural KZN. Toyota has therefore sponsored 10 Hilux 2.4 SRX 4x4 Double Cabs for nine months with the express purpose of helping health workers reach these sometimes-inaccessible areas. The vehicles

will enable officials to, first, track down all close contacts associated with infected individuals and, second, conduct testing to determine what further steps are needed to curtail the spread of the disease.”

Making a difference Both the KZN DoH and eThekwini Municipality have welcomed TSAM’s intervention. eThekwini Executive Mayor Cllr Mxolisi Kaunda states, “Since this pandemic hit our shores, we have witnessed a strong collaboration between government and private sector in the fight against Covid-19. Toyota is one of

Andrew Kirby, President and CEO of TSAM

the private sector companies that has been at the forefront of fighting this pandemic. We once again welcome this donation, as it will go a long way towards minimising the spread of this virus. This is a clear indication that, if government and private sector work together, we can overcome all developmental challenges facing the country.” The MOA builds on TSAM’s already robust CSR programme. Over the last few months, TSAM also donated more than 65 000 litres of sanitiser and thousands of face masks to the South African taxi industry, while 2 000 food parcels (each containing groceries to sustain a family of four for a month) were distributed to communities around the Prospecton Plant in Durban and Atlas Warehouse in Johannesburg. In addition, TSAM has supported more than 270 schools in Gauteng and KZN with readiness packs – including face shields for all the educators, sanitisers, educational posters and infrared thermometers.

L-R: Andrew Kirby; Jenny Maré, GM of Corporate Affairs at TSAM; KZN Health MEC Nomagugu Simelane-Zulu; KZN Premier Sihle Zikalala; and eThekwini Executive Mayor Mxolisi Kaunda at the signing of the MOA IMIESA October 2020


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“In collaboration with eThekwini Water and Sanitation department, AECI Water ensure water and food security through the recent upgrade of the Mkhizwana potable water plant - an imperative not only in KZN but on the continent as a whole. Alone we can do so little, together we can do so much� Dean Mulqueeny Chairman, AECI Water

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Supporting water and food security


lobally, 2.2 billion people lack access to safely managed drinking water services and 4.2 billion people – more than half of the global population – do not have access to safely managed sanitation services. In South Africa, these figures sit at over 3 million and 14 million, respectively. Added to this, municipalities are losing around 1 660 million m3 per year through non-revenue water and the country is projected to face a 17% water deficit by 2030. With water at the core of sustainable socioeconomic development, food production and healthy ecosystems, AECI WATER has refocused its business and offerings to uplift the lives and standards of communities and the economy.

Water capabilities AECI WATER aims to support all local governments and utilities in achieving their objectives of becoming resilient smart cities, through the support and provision of new and existing in-house technologies for

the monitoring and control of critical water systems. The company has vast experience and expertise in the treatment and management of potable and sewage water. This includes highlevel capabilities in implementing alternative water source treatment technologies, including groundwater treatment, water reclamation and reuse, and desalination. For potable water treatment, AECI WATER manufactures and supplies a comprehensive range of coagulants and flocculants for liquidsolid separation, as well as supplies small-tomedium-sized free-standing, containerised and engineered treatment plants. The company also has the unique capability and expertise to offer containerised plug-andplay sewage treatment systems. Additional wastewater treatment offerings include a wide range of products to condition sludge prior to thickening or dewatering, as well as for final effluent disinfection. Sludge handling is often the single largest cost in wastewater plants. AECI WATER’s products allow for cost-effective treatment, paired with the expertise to address all the sludge management challenges faced by utilities. Experts can also advise on the use of advanced anaerobic digestion for combined heat and power production. Added to this, the company has mobile laboratory testing capabilities and offers a range of smart monitoring and control technologies.

Proven track record AECI WATER has been involved in numerous projects to supply safe drinking water, making a difference to customers and communities.

The Southern African region, and South Africa in particular, is facing a looming water crisis. AECI WATER is working collaboratively to resolve the water challenges by delivering packaged water solutions based on its diverse experience and world-class solutions. One such project saw AECI WATER provide safe drinking water to several clinics and schools in Hammanskraal by setting up a filling station that the City of Tshwane can use to supply safe drinking water to the community. AECI WATER also collaborated with the eThekwini Water and Sanitation Department to supply potable water to the community through an upgrade of the Mkhizwana treatment plant – an imperative for the community, the province and the country. Other notable projects include, among others, the construction of a water treatment plant at Sea Harvest’s Saldanha fresh fish processing factories to treat effluent or seawater, and the deployment of desalination plants at Lucky Star’s fishmeal operations at St Helena Bay and Laaiplek, which have produced more than 50 million litres of water since April 2018. “At AECI WATER, we work with our customers to build long-term relationships, solve complex challenges, and develop innovative solutions that add value to our customers’ operations,” says Bernette Sekati, Executive Director: Public Water Division, AECI WATER. Dean Mulqueeny, Chairman, AECI WATER, concludes, “Through understanding our customer processes, we are able to offer customised solutions, proven technologies and world-class chemistries, with the ultimate goal of uplifting communities, improving health and hygiene, and achieving greater water and food security. Alone, we can do so little; together, we can do so much.”

IMIESA October 2020


SIYAZI is an award-winning South African transport solu�ons provider that services both the public and private sectors. The company’s main service offering focuses on public transport planning/ development and traffic engineering, for everything from municipal to residen�al and commercial developments.

PUBLIC TRANSPORT PLANNING Transport Registers Public Transport Plans Integrated Transport Plans Freight, Public Transport (Taxis, buses), Modal Integration Needs determination System design Taxi rank and bus terminus design Taxi industry facilitation Taxi Rank Management Strategies and Central Management Determining of Transportation Vision, goals and objectives on various spheres of government Policy development Modal integration Taxi Recapitalization plans


With offices based in the Free State, Gauteng, KwaZulu-Natal, Limpopo, Mpumalanga and the North West, SIYAZI provides services that include:

Data surveys Database analyses Geographical Information Systems (GIS) development Development planning Travel demand management and modelling Community service (conflict handling, mediation and facilitation) Training and capacity building Economic analysis, municipal finance Public transport management

TRAFFIC ENGINEERING Impact Studies for developments such as shopping centres, filling stations and residential areas Setting and synchronisation of traffic lights Parking studies, including issues such as parking layout, parking demand and parking supply Designs for pedestrian and bicycle facilities.

Policy and strategy development Development of cooperatives

SIYAZI is a registered member of the Engineering Council of South Africa (ECSA).

Together, SIYAZI and the various role players in the projects we work on can make a difference in the delivery of effective solutions to meet the needs of people from grassroots level all the way up to executive management.

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Incentivising a catalytic development


he Brickworks Development, situated in the Avoca Development Node, north of Durban, is expected to change the area’s landscape. The 350 ha node will be transformed into an industrial and business estate for logistics and light industrial uses, with a potential capital investment of R10 billion. According to eThekwini Deputy Mayor Belinda Scott, the Brickworks Development will provide socio-economic transformation and contribute to employment by creating an estimated 23 000 construction jobs and 13 500 permanent jobs. “The location of the Brickworks Development, along with the other developments in the Avoca Node, such as Caneridge and Rohill (Northfields), will create much needed employment opportunities for the surrounding communities like the Mt Moriah, Duffs Road, Inanda and KwaMashu residential areas. It is one of the few remaining large infill sites in the area,” she said. The site is currently used by Corobrik to mine clay and manufacture related brick and paving products.

Creating an environment for investment The land developer, Investec Property, intends to develop the site in three phases over 15 years. The proposed development will require an investment of over R1 billion in infrastructure development. The long development time poses a significant risk to the developer, particularly with respect to potential rates increases on the

ETHEKWINI The City of Durban unlocked a multimillion-rand catalytic development through its recent agreement to incentivise the Brickworks Development.

undeveloped phases of the project. To address this and incentivise the development, a five-year rates rebate is being proposed for each of the three phases. “As part of the city’s strategy to create a conducive environment for investment, it offers a substantial rates rebate to investors and developers. This forms part of the city’s Rates Policy and Economic Development Incentive Policy (EDIP), which aids investment in our city that contributes to job creation,” explains Scott. The EDIP aims to position eThekwini as a preferred investment destination and focuses on supporting new investments based on their potential and future contribution to economic growth, spatial regeneration and job creation within the municipal area, in accordance with the strategic objectives of the municipality. “In order to incentivise the Brickworks Development and realise the anticipated socio-economic benefits resulting from the development, including the increased rates income for the city once the development is undertaken, a rates rebate has been agreed upon for the development period,” Scott continues. Although there will be an anticipated rates rebate of R34 million over the 15-year period, it is estimated that the rates income for this site will increase from the current R3.4 million per annum

to an estimated R190 million per annum following the completion of the development. The intention is for the rebate to cease on an incremental basis as an occupation certificate is issued for any completed top structure development, on a site by site basis. “Through our partnership with Corobrik, who for more than 100 years has provided eThekwini with bricks to build some of the most iconic buildings in the city, we were able to identify this unique development opportunity. The collaborative nature of this undertaking was made possible through eThekwini’s innovative establishment of the city’s ‘One Stop’ Catalytic Projects Unit alongside its proactive and unique Rates Rebate Policy, aimed at encouraging development,” says David Rosmarin, joint chief executive, Investec Property. “eThekwini plays an integral role in the economy of South Africa, serving as the logistics hub and main entry port into the country. The Brickworks Development will further strengthen and enhance this role while stimulating regional economic development. Investec Property is proud to be a part of this unique development and we thank Executive Mayor Mxolisi Kaunda and city officials who contributed in bringing this project to fruition,” adds Rosmarin.

IMIESA October 2020


Durban Point Promenade

S�mula�ng economic growth in eThekwini

A key catalyst for the redevelopment and regenera�on of the inner city providing housing, employment, commercial, retail, and recrea�onal facili�es for eThekwini residents.

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IMIESA October 2020

Building Durban Point Promenade Forming part of the redevelopment of the master plan for the entire Durban Point Precinct, the newly developed Durban Point Promenade intends to ensure free and unrestricted access to the beach for all members of the public.


he new Point Promenade extends a total length of 680 m from the end of the existing promenade at uShaka Marine World to the Durban Harbour entrance. Considered the backbone of the entire Durban Point Precinct, it facilitates the highrise beachfront development and continues the highly successful promenade on the Durban beachfront. EThekwini Municipality and the Durban Point Development Company (as the implementing agent) appointed NAKO ILISO as the principal agent and civil and structural engineers on the project, together with various other consultants for other workstreams. The result is a two-level reinforced concrete structure located between the erosion line and the building setback lines. It provides a public landscaped promenade on the upper level with a public car park and public beach

amenities, along with the Point Watersports Club and Seinne Netters, housed underneath.

Design and construction highlights Developing Durban Point Promenade required several innovative construction methods. Due to the existing sandy-type soils and the absence of bedrock at depths greater than 25 m, Continuous Flight Auger (CFA) type piles were designed as shaft friction piles to varying depths up to 18 m. The promenade foundations consist of pile caps and ground beams. All pile caps are supported by at least two 600 mm diameter CFA piles, which accommodate the large column loads, while the ground beams are supported by 450 mm diameter CFA piles. Ground beams have been designed to reduce the spans of the lower promenade and to provide lateral bracing to the pile caps. An important design consideration was the establishment of the level of the lower floor of the promenade infrastructure to deal with the anticipated wave run-up levels identified in the coastal processes study. The proposed ground-floor level of 3.8 m MSL (mean sea level) will be able to accommodate the 100-year return period storm event with the aid of a vegetated dune buffer on the seaward side of the promenade, except for the northern end where a run-up level of 4.35 MSL is anticipated. In this area, the northern ramp to the promenade will mitigate the anticipated wave run-up levels. Sheet piling will provide


further shore protection throughout the lifespan of the structure. The lower-level slab has been designed as a reinforced concrete suspended slab due to the low bearing capacity and cohesionless sand types that are constantly affected by the fluctuating water table. Conventional permanent formwork has been replaced with a cement-stabilised in-situ material alternative. The upper level has been designed as a prestressed flat slab to accommodate the large spans. The curved profile of the slab edge presented a challenge for the end blocks, instead requiring recessed anchor blocks. The pre-stressing supplier undertook the design, supply and installation of their unique DYWIDAG Bonded Post-Tensioning System. This system provided for increased spans by reducing the number of columns, thereby creating a larger column-free area, which allows for better manoeuvring of vehicles in the parking areas, as well as better utilisation and unrestricted views within the private facilities. Drop panels have also been designed on the internal spans of the secondlevel slab to account for punching shear. With a construction cost of R305 million, Durban Point Promenade has served to reverse the negative perceptions that have plagued the entire Point development, through the provision of well-accepted and significant physical infrastructure that preserves public access to the entire beach.

IMIESA October 2020


Joint International Conference with IMESA & IAWEES


(Institute of Municipal Engineering of Southern Africa & International Association of Water, Environment, Energy and Society)


CALL FOR ABSTRACTS for paper and poster presentations



CATEGORIES • Environment

• Energy

• Water and Sanitation

• Financial, Legal and Regulatory

• Transport, Roads

• Data management

and Stormwater


09 April 2021 (poster presentations and abstract submissions)

marketing@imesa.org.za | tel +27 031 266 3263

Contact Melanie Stemmer for an entry form or download it from the website. CONFERENCE ENDORSED BY

t: +27 (031)266 3263 e: conference@imesa.org.za marketing@imesa.org.za www.imesa.org.za




Durban leads in climate action

In September 2020, eThekwini Executive Mayor Mxolisi Kaunda launched the Durban Climate Action Plan. The first in Africa and one of only 12 worldwide, it is seen as a significant milestone in local climate change action.


o address the need for rapid climate-related transformation, eThekwini Municipality, with support from the C40 Cities Climate Leadership Group, has developed a Climate Action Plan (CAP) that builds on the 2015 Durban Climate Change Strategy. The goal of the plan is to ramp up the ambition and action required to limit the global temperature increase to 1.5°C, and thereby limit impacts facing vulnerable communities. The CAP comprises of 33 actions and 149 subactions aligned to nine thematic areas: energy, transport, water and flooding, waste, biodiversity, food security, health, sea-level rise, and vulnerable communities. These provide a pathway for eThekwini to achieve climate resilience and carbon neutrality by 2050.

City targets Kaunda, who is also the C40 vice-chair for the African region, said eThekwini has prioritised bold, transformative actions in the electricity and transport sectors, while aiming to promote affordable, clean energy and transportation for the poor and previously disadvantaged communities. eThekwini has set out to achieve a 40% reduction in emissions, from a 2015 baseline, by 2030 and an 80% reduction by 2050 – and is committed to identifying various opportunities

to achieve carbon neutrality. Medium-term goals include having 40% of electricity supplied by renewable energy, increasing alternative water supply capacity by 100%, having 55% of passengers using public and non-motorised transport, and a 50% diversion of waste from landfill. Long-term goals include 100% of energy being supplied by renewable sources, a 100% increase of alternative water supply capacity, 70% of passengers using public and nonmotorised transport, compliance with the WHO air quality standards, as well as 90% diversion of waste from landfill by 2050. Among the initiatives planned to achieve these goals is the implementation of a smart electricity grid that enables bidirectional power flow and includes large-scale renewable energy resources from national and locally produced small-scale embedded generation systems, like rooftop solar panels. The city also plans to expand its network of electric buses and significantly reduce private car trips. To tackle food insecurity, eThekwini plans to achieve a 50% increase in locally produced food by 2030 and reduce the volume of goodquality leftover food waste by 80%. The city has already achieved some key milestones in response to climate change in recent years, including the establishment

of the Energy Office, the Climate Protection Branch, the Durban Climate Change Strategy, and the Climate Change Technical Task Team.

Partnerships are key The municipality has called for the support of national and provincial government, the private sector, civil society and citizens to enable it to meet the plan’s ambitious targets. “Durban, as a signatory of the Inclusive Climate Action Declaration, will ensure that it eradicates poverty and increases inclusiveness in its communities. It is important to note that our plan recognises that the city cannot achieve these targets alone and will rely on establishing strong social compacts between government, labour, business and civil society,” said Kaunda. The city plans to broadly share its story of developing the CAP through the compiled Learning Journey: Durban Climate Action Plan. This document, developed in partnership with the Municipal Institute of Learning, highlights some of the lessons learned, and challenges encountered in city-level climate action planning. The CAP will form the cornerstone of the Integrated Implementation Plan for the Durban Climate Change Strategy, which is scheduled for completion by the end of the 2020/21 financial year.

IMIESA October 2020



Water strategies FOR A DRY CITY Nelson Mandela Bay Metropolitan Municipality (NMBM) is facing a particularly severe drought, which is placing major pressure on its water demand management planning. Barry Martin, senior director: Water and Sanitation, expands on the intervention strategies. By Alastair Currie


rom a water security standpoint, the bulk of the city’s dams are now below or reaching the minimum limit. In response, the municipality’s emergency planning strongly influences how the city prioritises infrastructure projects. The municipality’s current approved budget for water is around R324 million, with approximately R161 million allocated for sanitation. Historically, the city’s regional water security planning has been bolstered by external supply from the Gariep Dam, situated some 450 km from Port Elizabeth. Feeding into the Nooitgedacht Water

Treatment Works (WTW), the volume of water received is governed at some 160 Mℓ according to NMBM’s water-use license. However, Nooitgedacht’s peak demand is 210 Mℓ/day. “Our challenge as a city is that we cannot sustain our existing overall consumption of around 290 Mℓ/day,” explains Martin. “Current capacity comes to approximately 268 Mℓ/day, so we have a deficit of some 30/40 Mℓ/day.” One of the solutions is an increase in the allocation from Gariep Dam due to efficiencies achieved by the Department of Water and Sanitation within the canal feeder system. This could translate into a further 50 Mℓ/day available as an average flow. NMBM is in the process of making an additional licence application, which, if accepted, will come into effect around June 2021.

Coegakop Another positive development is the construction of the new Coegakop WTW, which is due to be commissioned in 24 months’ time. Supply will be sourced from the Coegakop groundwater wellfield development site on which the WTW will be situated. Once on stream, the plant will supply at least 15 Mℓ/day, but this could be as much as 20 Mℓ/day. “Combined, Nooitgedacht and Coegakop will push the additional supply up to 70 Mℓ/day,

which will provide the interim relief we need to sustain our communities and economy,” says Martin. The Coega Development Corporation also intends to build a desalination plant within its Special Economic Zone (SEZ), which will take some pressure off the city’s overall supply.

Pressure management and leak repair The biggest challenge is managing the underground infrastructure assets. Physical water losses are currently estimated at between 30% and 35%. As part of its non-revenue water loss intervention, NMBM has developed a 10-year business plan. Pipeline and meter replacement and the identification and management of high-pressure zones have been given priority. For these and allied initiatives, the city has secured R150 million in loan funding and will start to roll out new projects during the 2020/21 financial year. So far, some 70 pressure zones have been installed. In some areas, readings of 8 bar to 9 bar have been recorded, which far exceeds optimal pipeline operating conditions. A further 10 to 15 areas have now been identified for future pressure management studies. “Reducing the pressure reduces the

Nooitgedagt/Coega Low Level Scheme: Phase 3


IMIESA October 2020


of specified volumes of domestic wastewater from the nearby Motherwell township to optimise the process design.

Servicing informal settlements

In addition to engineered interventions, Nelson Mandela Bay Metropolitan Municipality plans to ramp up its water conservation campaigns to obtain more buy-in from the public, since improved service delivery tends to go hand in hand with increased consumption

fatigue on the pipe, but it doesn’t eradicate leaks; however, it reduces the leakage rate. It’s an ongoing condition assessment programme, where older pipeline sections are progressively inspected for age and performance and then either repaired or replaced. Budgets for pipeline replacement programmes have been approved and we are now packaging the areas,” Martin explains. The city has between 7 000 km and 8 000 km of underground water and sanitation infrastructure that needs to be managed and modernised. That’s in addition to some 100 water and sanitation pump stations. On the maintenance side, NMBM recently repaired around 15 700 water leaks recorded on its asset management system. This is estimated to have saved around 10 Mℓ/day in water losses. Further gains will be achieved as NMBM’s maintenance teams plug the gaps.

Treatment works upgrades In terms of process engineering, the city is progressively upgrading all its WTWs and wastewater treatment works (WWTWs). In addition to Nooitgedacht, for example, the city is in the last stages of upgrading

its Loerie WTW, built some 60 years ago. Nooitgedacht’s first phase was completed in 1990 and the city is now carrying out a phase-three upgrade. A strategic pump station at Sea View is also being upgraded. Future work includes modernisation at the Churchill WTW. Average compliance across NMBM’s WWTW facilities is between 75% to 80%. Certain plants are higher. The main issue is the constant battle to discourage illegal dumping, oil and industrial effluent being prime examples that overload the system, push up treatment costs and affect compliance. Current upgrade projects include the Fish Water Flats WWTW, where the project team has constructed a new inlet works, electrical system and sludge handling capability in Phase I. Work in progress on Phase II includes upgrades to elements that include aeration lane efficiencies and the sedimentation tanks. NMBM is also investigating alternative technologies for its smaller WWTWs, which could include the installation of biomass reactors. There are also plans in the pipeline to build a dedicated WWTW at the Coega SEZ. The proposal makes provision for the diversion

Alongside these and other initiatives, the city is committed to improving water and sanitation services for its informal settlements, estimated to represent between 10% and 20% of the overall population of some 1.25 million. Up to 2018, NMBM was on track with its bucket eradication programme, and basic water and sanitation programmes. It now needs to re-evaluate everything, given the constant influx of people from surrounding rural areas. Working in conjunction with the Department of Human Settlements, the present metropolitan spatial development framework is under review as the city maps out the next water and sanitation master plan. “In terms of the master plan drafted in 2005, everything outlined in that document has been implemented. The lessons learnt to date will be applied in terms of future planning and implementation,” Martin explains.

Conservation campaigns In addition to engineered interventions, the city plans to ramp up its water conservation campaigns to obtain more buy-in from the public, since improved service delivery tends to go hand in hand with increased consumption. On the commercial and industrial side, NMBM has been encouraged by an increasing number of businesses effecting water-efficient processes. “We’ve typically experienced a drought cycle every four to five years; however, the trend in the past 10 years has been particularly severe and shows no signs of improving. For this reason, we need a complete mindset shift in how we design potable water and waterborne sanitation systems. Desalination and reuse are definitely part of that discussion, as is a permanent change in water use behaviour,” Martin concludes.


Towards energy efficient plants

In an effor t to upscale energy projects in South Africa’s municipal sector, the Depar tment of Mineral Resources and Energy (DMRE) has begun to roll out training around renewable energy and energy efficiency at several municipal wastewater treatment works (WWTWs). By Danielle Petterson


he DMRE, in collaboration with the South AfricanGerman Energy Programme (Sagen) implemented by the Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ), has given financial and technical support to eight municipalities, targeting a total of 14 WWTWs, to conduct field work and develop pre-feasibility studies with the aim of compiling bankable project funding applications. The project provided training to collect data from energy-consuming equipment and plant buildings and to convert it into a feasibility study that contains billing information, technical solutions, costing and recommendations to implement renewable energy and energy efficiency at these plants. The ultimate goal is to develop capacity within the municipalities to build a business case and implement projects that optimise


IMIESA October 2020

energy use via energy reduction and electricity production, thereby savings costs and reducing the environmental footprint. “The training will enable municipalities to identify energy savings opportunities and improve the operation of their WWTWs. Saving one unit of energy is significantly cheaper than producing one unit – making energy efficiency the quickest, cheapest and most direct way of addressing high electricity costs and the electricity supply constraints,” notes Marlett Balmer, head: Energy Efficiency, Sagen.

Energy reduction and optimisation South Africa’s WWTWs typically have a high specific power consumption of >1.8 kWh/m3, compared to international benchmarks of 0.3-0.7 kWh/m3. According to Marlene van der Merwe-Botha, director, Water Group Holdings, many of South Africa’s WWTWs are old and still use equipment that was bought decades ago, much of which is not energy efficient. The Water Group was appointed by GIZ Sagen as an expert consultant to develop and provide training to the eight municipalities on how to collect the necessary data and use it to develop feasibility studies.

“The reduction of energy consumption at WWTWs is not yet a well-established practice in South Africa. Drivers such as the increasing cost of electricity, reliability of supply and the environmental footprint of WWTWs result in a focus on improving the energy efficiency of electrical motors and using other technologies to reduce energy use at WWTWs. Energyefficiency measures could save between 10% and 30% of a plant’s energy use, with typical payback periods of one to five years, making this a wise investment,” explains Van der Merwe-Botha. In a typical energy assessment, the first step is to determine a WWTW’s electricity use. This provides a verified baseline from which future savings can be calculated, she explains. Thereafter, municipalities should identify benchmarks that reflect typical energy use by the plant. Popular baselines include kWh/m3 effluent treated and the percentage saving that could potentially be achieved. These targets could be calculated for the entire plant, per process unit, per process equipment, or per technology type. According to Van der Merwe-Botha, municipalities should then assess their electricity bill to determine the electricity consumption and associated monetary charges of the plant. It is important to determine the unit cost R/kWh during peak, standard and off-peak time of use, or the block tariff if applicable.


The energy use by different process units and equipment should be determined and the large energy consumers (e.g. aeration and pumping) clustered and quantified in terms of the cost and kWh usage. Based on this information, municipalities can identify energy saving or reduction measures for the plant, along with targets. This could include replacing old motors and pumps with energy-efficient equipment as soon as their life expires, applying variablespeed drives and dissolved oxygen control to aeration, applying power factor correction, shifting load from peak use to standard or off-peak use times, optimising lighting and air-conditioning systems in buildings, and reducing extraneous flow into the plant, such as stormwater or groundwater ingress.

Energy efficiency measures could save between 10% and 30% of a plant’s energy use, with payback periods of one to five years, making this a wise investment.” Benchmarks should be used to estimate how much energy is expected to be saved, both in terms of electricity units and rand value. After determining the cost and payback period, municipalities can prioritise and implement energy-reduction measures as part of a phased, multiyear project. Van der MerweBotha notes that municipalities must continue to monitor the impact and roll-out of these measures until the plant reaches its target.

“The sooner municipalities start to analyse their electrical bills, establish baseline use and targets, and begin to identify and implement measures to reduce energy use, the sooner we will reap the cost, operational and environmental benefits,” says Van der Merwe-Botha.

Resource recovery plants Improving energy efficiency is just the first step. Ultimately, WWTWs should be transformed into ‘resource recovery plants’ that generate energy from biogas and create valuable by-products from biosolids, nutrients and final water. Typical municipal WWTWs are extremely energy intensive to run, requiring around 1.3 MW per 100 Mℓ/day. With good processes in place, plants making use of anaerobic digestion for sludge stabilisation could produce 60% or more of their energy requirements via combined heat and power generation at the plant. A 2016 water research study verified that 108 active anaerobic digesters are operational in South Africa at municipal WWTWs, and even more at plants owned by the Department of Public Works. The potential is thus significant. Unfortunately, the potential is not fully realised, as a result of the infrastructure, operational and maintenance shortfalls at WWTWs. Coupled with a lack of expertise and finance, these prohibiting factors prevent the uptake of these processes in South Africa. Van der Merwe-Botha also conveys that municipalities identified the absence of incentives and pricing structures that promote electricity production from biogas and the reuse of nutrients and biosolids, as well as an

absence of a conducive legislative and procurement framework as prohibitive factors. For plants where cogeneration is financially feasible, options of codigestion and reducing the impact of greenhouse gas emissions offer significant benefits to WWTW owners. Despite high costs for establishing a resource recovery plant, the payback period can be just a few years. To assist municipalities, GIZ Sagen supported the development of a practical guideline, called Anaerobic Digestion of Municipal Wastewater Sludge, compiled by Van der Merwe-Botha. The guide demonstrates the relationship between maintenance, design, operation and business processes, and how they should work together to ensure that an anaerobic digester produces biogas, final effluent and biosolids of the highest quality. “By moving towards the creation of resource recovery plants, we acknowledge the commercial value of finite resources such as nutrients, organics, energy and industrial-grade water from WWTWs. We need to apply proven business models, incentivise partnerships and establish a conducive regulatory environment to unlock these resources and stimulate investment,” notes Van der Merwe Botha. “It is an exciting and opportune time to be a wastewater practitioner in South Africa. The future process controller’s competence will reach beyond the operation of the treatment facility to include energy management as well. Process controllers will be responsible for championing this in the future and this is how we start to close the gap between water and energy and – hopefully, one day – food as well,” she concludes.

IMIESA October 2020



When it comes to reverse osmosis (RO), two proper ties are typically of great interest and impor tance: energy consumption and brine discharge. By Nico-Ben Janse van Rensburg

Optimising permeate flow in RO plants


oth energy consumption and brine discharge have received great attention and innovation over the years, with the introduction of membranes operating at lower pressures while maintaining high rejection, energy recovery devices, high-efficiency pumps and motors, as well speciality membranes for high recovery. The distribution of permeate flow across the membranes in the pressure vessels is often overlooked. QFS believes that this is an important factor in RO design, which can result in a better return on investment (ROI) and lower energy costs on longevity of the lead membranes due to lower risk of exceeding the flux limit.

Problem statement The first element in a pressure vessel receives the lowest concentration of dissolved solids at the feed pressure of the system. A portion of the water passes through the membrane as permeate, leaving a more concentrated feed at a lower flow rate and slightly lower pressure to be fed to the second membrane element. The increase in dissolved solids increases the osmotic pressure, which in turn reduces permeate flow. The permeate flow is further decreased by the fact that the driving pressure is also lower. This leads to the formulation of the following hypothesis: optimal permeate flow distribution in RO is critical in the sustainable design and optimisation of an RO process.

operated in parallel with two similar plants drawing from the same seawater source. An audit was done on the existing two plants to ascertain their performance and compare them to the new plant, which has been optimally designed. The existing plants are labelled RO A and RO B respectively and the new plant designed for optimal permeate flow balancing by QFS is labelled RO C. Figure 1 shows the permeate flow rate of each membrane element in the



A plant was constructed and is FIGURE 1 Permeate flow per element Nico-Ben Janse van Rensburg, process engineer, QFS


IMIESA October 2020

vessel from the raw water feed side to the brine side. RO A and RO B both show a sharp decline in permeate flow from one element to the next. This is a typical exponential decay where the permeate flow approaches zero from one element to the next. Production of membrane element six for both RO A and RO drops to about 0.1 m3/h, producing small volumes of product water compared to the first membrane element. RO C, which has been designed for optimal permeate flow balance, shows less rapid decay. The advantages to the design optimisation are not clear at this stage, and two questions need to be answered: •  Does permeate flow balancing have any financial advantages? •  Does permeate flow balancing have any operational advantages?

To investigate the advantage on capital expenses, the ROI for each individual membrane is investigated next to the ROI for


FIGURE 2 ROI on membrane elements

the entire pressure vessel. The following assumptions are made in the calculation: •  Replacement cost of a membrane is R11 475, including transport and installation on-site. • Water is sold at R20 – this is a hypothetical number and may vary greatly; the trends remain the same. •  Membrane life span is five years, which can be significantly extended through good pre-treatment. •  Inflation of 4% per annum, both for membrane replacement costs and water sale costs. • The plant operates 24 hours per day, with a three-hour shutdown for cleaning in place every 28 days. •  ROI is based on turnover and operating costs for the rest of the plant are not considered. Figure 2 shows the individual membrane element ROI in the top row. Both RO A and RO B have negligible ROI for elements five and six. The fact that RO A is pushed much harder than RO B only affects elements one, two and three. RO C shows a smaller spread of ROI from elements one to six, and a lower yield in the first membrane element, yet the cumulative production seen in the bottom row of plots in Figure 2 is significantly greater. As this is the same feedwater, it is clear from the plots that RO C operates at a lower feed pressure than RO A judging by the lower permeate flow of the first membrane element – yet the total production is significantly more. RO C is

therefore more energy efficient and has the potential for a higher recovery than RO A. Pushing RO A further for better recovery will only exceed the operational limits of the first three membranes, while no improvement is seen on the last three membranes. A further advantage with optimal flow balancing is that RO C has seven membrane elements and the seventh element provides a significant contribution. The cumulative ROI plot for RO C shows the ROI for all seven elements, but for fair comparison, only the first six elements are considered and are shown with the red line in Figure 2.

Conclusions There is a great improvement in ROI for RO C with optimised flow balancing. Table 1 not only shows a significant improvement in ROI for the whole pressure vessel, but an even greater improvement in ROI for elements four to six.

Although the discussions and numbers are centred around ROI, which is critical when budgeting for long-term maintenance, there are some other benefits that are also important in terms of sustainable design: •  The disposal of used membranes remains an environmental concern. A membrane that hardly produces water is unnecessary wastage. •  Lower pressure results in better energy efficiency and therefore reduced operational costs and carbon dioxide emissions. • Improved ROI can be the source of funds for further optimisation, such as upgrading energy recovery devices and motors for more efficient operation. Although this study was done on a seawater plant with a single stage, the same principles would apply to any RO skid with any number of stages. Flow balancing has both financial and environmental advantages.

TABLE 1 Pressure vessel total flow and ROI




Total Permeate Flow (m3/h)




ROI Element 1

R2 908 972.03

R1 733 004.46

R2 179 872.14

ROI Element 2

R2 015 236.68

R1 215 578.73

R1 897 639.92

ROI Element 3

R1 262 617.43

R792 230.40

R1 615 407.70

ROI Element 4

R721 672.35

R509 998.19

R1 356 694.84

ROI Element 5

R415 920.78

R321 843.38

R1 097 981.97

ROI Element 6

R227 765.97

R204 246.62

R862 788.46


R7 552 185.24

R4 776 901.78

R9 010 385.03

IMIESA October 2020



Supporting municipalities in treatment plant upgrades

Where municipalities nur ture their internal technical exper tise and commit the necessar y funding to wastewater treatment, they can rely on a range of specialised input from consulting engineers to help get treatment plants running optimally. By Tiaan Bauman


RK Consulting has applied its engineering and scientific expertise to municipal, provincial and national water projects for decades and is currently working on 10 wastewater treatment projects in Gauteng. The condition of the treatment plants we are seeing varies widely between municipalities. While some plants continue to function well, others are non-operational for a variety of reasons. The main concern is that substandard operation means effluent is not properly treated before it leaves the plant. This raises the risk of contamination as the water enters natural watercourses and flows downstream – potentially posing health risks to residents and hazards to the environment.

Constant upgrading In many cases, the plants are under-capacity with regard to both their hydraulic loading


IMIESA October 2020

and organic loading. In terms of their hydraulic load, the volumes of wastewater entering many plants are simply greater than the design capacity of the facility. Organic loading also varies, depending on the type and strength of the effluent being treated. The results are aggravated if the plant’s performance is not up to standard. Where plants are not coping with the volumes, it is vital to plan and implement the necessary upgrades and expansions. In a country like South Africa, where urbanisation is still strong, it is unsurprising that treatment plants need regular upgrading to keep up with rising numbers. The forward planning function at a municipal level therefore has an important role in informing the technical requirements of facilities like wastewater treatment works. It is also a field in which consulting engineers work closely with municipalities – not just in the large urban centres, but also in smaller

Flooding due to hydraulic overloading of the WWTW

towns and rural areas. The wide range of professional disciplines in our industr y includes civil engineers, process engineers and water scientists – each with a vital contribution to wastewater treatment. Finance is certainly a constraint in terms of the necessary maintenance and upgrades, and the budgets allocated have often been inadequate over a long period of time, leading to a significant deterioration of infrastructure. Recent discussions at the highest levels of government, however, suggest that there is more attention being paid to making the necessary resources available.

Prioritising needs Even under these resource-constrained


Tiaan Bauman, principal civil engineer and associate partner, SRK Consulting

ABOUT TIAAN BAUMAN Tiaan Bauman is an associate partner and principal civil engineer at SRK Consulting, based in Johannesburg. He has over 23 years of experience in civil engineering in the public, private and mining sectors. He specialises in the fields of hydraulics, stormwater management, water and wastewater treatment plants, pump stations, pipelines, earth dams, tailings storage facilities, project/contract/construction management and dispute resolution. Bauman has worked on numerous projects in South Africa, Eritrea, Mozambique, Ghana and Lesotho. He is a member of SAICE and is professionally registered as a Pr. Eng (ECSA) and Pr. CPM (SACPCMP).

conditions, though, consulting engineers can contribute to keeping the improvement process moving along. For instance, a key consideration for every municipality – especially when budgets are tight – is to carefully prioritise spending. Working with the technical staff within a municipality, consulting engineers can conduct the necessary audits and studies that highlight where investment is most urgently required, and where it will deliver the most value for the residents of that area. This work forms a vital foundation for phasing the planning and roll-out of projects according to what is financially feasible. A technical audit on a treatment plant, for instance, can lead to a ‘status quo’ report that assesses in detail its condition, and what needs to be done to reach optimal operation levels. The design of the upgrade can then follow. This input, however, needs to be made in the context of the municipality’s

future planning priorities. It is the municipality’s role to be ‘close to the ground’ in terms of where and which infrastructure will be required in the coming years. For this reason, the technical capacity within municipalities is vital, making it a high priority for all municipalities to retain, nurture and develop these skills and experience. Town planning is one of the fields that will guide the future services to be provided to the area and its residents.

Maintenance for longevity The Covid-19 pandemic and subsequent lockdowns will certainly make the financial challenges of municipalities no easier. This heightens the importance of adequate maintenance of treatment plants, and the crucial role that a municipality’s technical staff and plant operators must play in


KOUGA TREATMENT WORKS UPGRADE In one of its recent projects, SRK Consulting was appointed as the consulting engineer for the upgrading of Kouga Local Municipality’s St Francis Bay Wastewater Treatment Works (WWTW) in the Eastern Cape. SRK designed and implemented the upgrading of the WWTW, including the additional infrastructure, to meet the increased volumetric and organic loading of the works by expanding the sludge-handling capacity to accommodate the increase in sludge volumes. The upgrades, which started in

making plants run smoothly and last as long as possible. Here too, consulting engineers can play a supportive role. Through our collaboration with treatment plant managers and other technical staff, the profession helps plan

February 2018 and were completed in February this year, increased the works’ capacity from 750 m3 per day to 2 000 m3 per day. The existing works were also refurbished. The plant serves the growing communities of St Francis Bay, Cape St Francis and Sea Vista. It will also cater for future development in the area. The upgrade ensures that effluent being discharged from the WWTW complies with the relevant standards. The plant has been operating since 1995 and has undergone two previous upgrades.

how maintenance is conducted and proposes the kinds of skills and schedules necessary. Many municipalities must deal with not just plant operations themselves, but with the security and maintenance of associated pumping systems and reticulation networks.

Current upgrading of a WWTW

Collaboration is key Water treatment is going to grow in importance to the public of South Africa, as we come to terms with our water scarcity as a country. Close partnerships between municipalities and the consulting engineering fraternity are contributing constructive solutions and can be leveraged to improve service delivery into the future.

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As water availability decreases and commercial buildings are faced with increasingly high utility bills, it becomes vital to reduce consumption and losses.


outh Africa is predicted to face a 17% water deficit by 2030. By implementing water-efficiency measures in and around commercial buildings and regularly checking for leaks, businesses can reduce operating costs and meet their sustainability goals. One of the best ways to manage water consumption is through a detailed water audit. This involves collecting the data necessary to estimate water use at the equipment level, surveying equipment to understand water consumption, investigating water-conservation opportunities, and conducting an economic analysis with the ultimate goal of reducing demand on freshwater resources. It is also necessary and advisable to schedule regular audits of the actual on-site plumbing infrastructure to monitor for excessive use and leaks. This will allow for immediate action to reduce water wastage.

Water-saving measures There are numerous water-saving options available and many have already been widely adopted in cities that have faced serious water shortages, like Cape Town. These include:


Repairing leaks Leaks in buildings’ water pipes are very common, especially as the pipes age. These often go unnoticed until the damage becomes evident on walls and ceilings. Leaking taps and toilets also account for significant losses. Installing water meters on all water take-off points and monitoring water use regularly can help to identify leaks. Building owners should conduct regular leak detection exercises and address leaks timeously. Plumbing fixtures Low-flow water fixtures can significantly reduce water consumption, especially when they are used often. As a result, the payback period can frequently be less than a year. Low-flow fixtures include aerators for taps, reduced-flow shower heads, and highefficiency toilet and urinal flush valves. Greywater and rainwater harvesting Greywater is water that has already been used – such as from showers, washing machines or bathroom sinks – that can be filtered and recycled for a secondary use. The most common uses for greywater are to flush toilets and irrigate gardens and surrounding landscaping. It can also be used in cooling systems. While it is very important to distinguish greywater from blackwater, optimised reuse of greywater in buildings can, in some instances, reduce potable water consumption by as much as 70%. Capturing and storing rainwater is another easy and effective way to conserve water with a viable payback period. Rainwater can be used in many of the same ways as greywater, or can be treated for potable use.



facebook.com/WaterWiseRSA twitter.com/water_wise www.waterwise.co.za/site/home.html


Water-wise gardens Where landscapes and gardens are present, the use of endemic, water-wise plants that are correctly hydrozoned can significantly reduce irrigation needs. Irrigation systems should also be designed according to water-wise principles, such as drip irrigation, and include water-saving technologies, such as rain sensors. Where possible, reused greywater or rainwater should be used. Education While water-saving technologies and designs are important, consumer education is vital to achieving water savings. It is important to educate users about waterscarcity issues and the impact of water conservation practices through signage and awareness campaigns at the point of use. Water meter monitoring Regular monitoring of water use on-site will quickly alert the user to possible leaks, faulty equipment or even changes in water use behaviour of staff, users or tenants. Installing automated meter reading devices would assist this process considerably. This is an essential tool in the fight to conserve water, to improve water efficiency of buildings, and to improve the bottom line.



IMIESA October 2020


Tracking water consumption is made easy by Water Wise

The Department of Water and Sanitation (DWS) aims to reduce water demand and increase supply to our growing population and economy to ensure water security by 2030. Currently, our waterstressed country faces economic water scarcity due to issues with the country’s water infrastructure, an ever-increasing demand on a limited supply and other environmental factors.

leaks, which can be easily detected if households monitor their water use by taking regular water meter readings. To assist people with this, Rand Water’s environmental brand, Water Wise, has developed a Water Wise calculator, which serves as a simple tool to estimate household water use and assist people in detecting high water-use activities and even leaks. The calculator, through a question–answer system, generates a water usage chart and an estimated cost (R) of the household’s water bill in a month. This estimated value should not be used to dispute municipal bills, however, as the value generated is based on general South African water use statistics. This calculator aims to assist the end-users to be responsible in ensuring optimal use of the water they receive.

Keeping track of water usage through the Water Footprint Assessment, founded by Arjen Hoekstra, is a step in the right direction that shines light on water use patterns in different aspects of society. With a deeper understanding of water consumption patterns and water balance, water utilities and municipalities can work towards improving their existing water-supply models, as well as addressing water wastage such as non-revenue water, and Achieving this will contribute to the bigger picture excessive use and leakages, in order to reduce of reduced water demand, water losses in large distribution networks. ensuring a sustainable supply of water for South Africa. End-users such as homeowners also encounter

www.randwater.co.za and click on the Water Wise logo FOR FURTHER INFORMATION ON WATER WISE, PLEASE CONTACT US ON: 0860 10 10 60

Designed for


custom builds

Robustness, power and best-in-class performance are all hallmarks of the Mercedes-Benz Arocs – a versatile truck purpose-designed for bodybuilders. Maretha Gerber, Head of Mercedes-Benz Trucks Southern Africa, expands on the key features and benefits.

Maretha Gerber, Head of Mercedes-Benz Trucks Southern Africa


ercedes-Benz’s Arocs targets the premium segment of the construction industry, where customers seek longevity and optimisation from their vehicles, combined with excellent in-cab ergonomics. Here, the Arocs excels in both on- and off-highway roles, given the end-use and model. To meet customer requirements, for example, the Arocs can serve as a freight carrier, tanker, tipper, concrete mixer, or waste collection vehicle, with the option of either a standard or all-wheel-drive powertrain. “All-purpose vehicles are increasingly becoming a thing of the past – that’s why the new range of Mercedes-Benz Trucks uses a common platform to develop a customtailored vehicle series for specific segments,” Gerber explains. The engine, transmission and axles are all manufactured by Mercedes-Benz trucks to ensure maximum efficiency and reliability. All models, including those for construction roles, are fitted with the PowerShift 3 automated

transmission, designed to optimise the shift strategy and perform faster gear changes.

The basis for the robustness of the Arocs is provided by the extremely strong frame consisting of cold-worked, high-strength fine-grained steel

After-market body fitment

One of the key features of the Arocs range is its bodybuilder friendliness

Engines and final drives Trucks are fitted with either hypoid or hubreduction axles as required by the vehicle application, which also determines the power delivery needed. Arocs models are fitted with either the 12.8-litre OM460 or 15.6-litre OM473 engine to meet outputs of between 360 hp and 520 hp. A strong focus has been placed on active safety, with various systems fitted as standard, depending on the model. These include driver airbag, Lane Keeping Assist, Attention Assist, as well as a rain sensor for the windscreen wipers. “The GVM on the Arocs range is between 18 000 kg and 41 000 kg. This means a body plus payload of between 7 000 kg and 22 900 kg, making the Arocs well suited for a diverse customer base,” Gerber explains. The new Arocs for construction comes standard with a one-year/unlimited km complete vehicle warranty and a three-year/250 000 km/5 000 hours standard warranty on the powertrain.

continues. Three main features contribute to this: • Mounting brackets specific to the body for which an Arocs model was configured are supplied as standard on the vehicle. •  50 mm hole spacing on the chassis also makes it easy to relocate components without drilling additional holes. • The second-generation PSM modules allow for even easier integration of additional electrical functions with the truck. “With the introduction of the Actros in 2018 and Arocs in 2019, Mercedes-Benz Trucks offered a complete model line-up across the long-haul, distribution and construction segments in the extra heavy-duty truck market,” says Gerber. “Both ranges were refreshed in 2020 to align the product line-up with that sold globally and to allow for customers to benefit from advancements that were made in terms of efficiency and safety,” Gerber concludes.

“One of the key features of the Arocs range is its bodybuilder friendliness. Special attention has been paid to simplify body fitment and reduce the time spent at the bodybuilder,” Gerber


IMIESA October 2020




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Concrete that works fine – without any sand Bryan Perrie, MD, The Concrete Institute


Among the main advantages of no-fines concrete (NFC) is economy in materials, higher thermal insulating values, lower shrinkage, and lower unit weight and density, says Bryan Perrie.


FC is obtained by eliminating the fine material – sand – from the normal concrete mix. Instead, single-sized coarse aggregates are surrounded and held together by a thin layer of cement paste to add strength. At each contact point, the paste forms a small fillet and these fillets hold the particles together and give strength to the concrete. NFC therefore has large interconnected voids and a lower density than conventional dense concrete. The structure of NFC makes it ideal for use as a drainage layer under reservoir and basement floors, and it can also serve as an insulating layer and damp-proofing material. Note, however, that NFC is definitely not suitable for drainage purposes where the water is soft or aggressive to concrete.


IMIESA October 2020

The composition of NFC comprises the following: - Common cement that complies with SANS 50197 should be used for NFC. Masonry cements are not suitable. - Water that is suitable for making conventional concrete should be used. - Aggregates: Clean, single-sized concrete stone should be used, and flaky aggregates should be avoided. The most commonly used aggregate is 19 mm crushed stone. Smaller stone may be used. Mixes made with smaller stone are in fact easier to handle and place but consume substantially more cement. For most applications, mix proportions range from 200 to 300 litres of aggregate per bag (50 kg) of cement. The water content of the mix is critical: if the paste is too dry, it will not coat the aggregate properly; if it is too wet, it will run off the aggregate particles and possibly block the voids at the bottom of the pour. Experience has shown that the water content should be between 18 and 22 litres of water per bag of cement. A cubic metre of compacted NFC requires about 1.05 m3 of stone, measured in the loose state. Cement content is between 260 kg and 180 kg, depending on mix ratio. NFC should be machine mixed, as hand mixing is difficult and

laborious. If hand mixing is unavoidable, it is best to mix the cement-water paste in a container prior to mixing the paste with the stone. When mixing the paste, mix the cement into the water rather than the other way around.

Placement and compaction NFC must be placed and compacted as soon as possible after mixing, as it tends to dry out rapidly because of its open structure. Compaction is achieved by rodding the concrete – vibration must not be used, and heavy tamping is not necessary. Because of its open structure, NFC must be protected from NFC is mainly used for load-bearing, cast-in-place external walls of singleand multi-storey housing, small retaining walls or damp-proofing sub-base material for concrete floors cast on grade


drying out and must be thoroughly wet-cured for at least seven days unless it is plastered, screeded or covered before that time.

Plastering NFC has a rough surface texture for plastering. Normal plaster mixes are used and the surface of the NFC must be dry when applying the plaster. Plastered NFC walls have some excellent qualities, but one drawback is that neither conventional wall plugs nor masonry

nails can be used for attaching fixtures to the walls. When used in underfloor drainage, roof insulation and domestic floors, NFC should be screeded within 72 hours of placing, with particular attention paid to wet curing the screed. Normal screed mixes of 100 to 130 litres of concrete sand per bag of cement should be used with enough water to produce a mix of plastic consistence. NFC has negligible flexural or tensile strength.

Compressive strength is usually between 5 MPa and 10 MPa at 28 days for mixes in the range mentioned previously. Higher strengths may be obtained by including 50 kg of fine sand per bag of cement. This increases the size of the fillets, and hence the strength, but reduces the voids and increases the density correspondingly. For further information, contact info@theconcreteinstitute.org.za or visit www.theconcreteinstitute.org.za.

SIKADUR-COMBIFLEXÂŽ SG BANDAGE SYSTEM HIGH PERFORMANCE JOINT SEALING SYSTEM Sikadur- CombiflexÂŽ SG Bandage is used for expansion, construction and connection joints. The system allows variable and high levels of movement in one or more directions, whilst maintaining a superior quality watertight seal.

Call us for more info: 010 823 5550 www.sika.co.za


Landfill containment: cost-effective longterm solutions

Arguably one of the most critical and far-reaching infrastructure decisions, secondary only to the selection and preparation of the landfill site, is the choice of liner and capping system to be put in place.


odern landfill best practice favours geomembranes as effective, durable barriers against liquid and gas leaching. To assure landfill owners and operators of a continuous, enduring seal across the entire area of the site, polyethylene geomembranes such as AKS Geoliner are specified as both lining and capping solutions.

It’s tough in a landfill Because of the demanding, often aggressive and hazardous environments of landfills, the installed lining should comply with various manufacturing standards and pass numerous pre-installation and in situ tests to ensure it will withstand a lifetime of harsh surroundings. Factors considered when designing and manufacturing AKS Geoliner include the on-site physical stresses likely to be encountered, the types of waste material, the expected depth of fill, the compaction methods envisaged, and the geophysical characteristics of the site. Making allowances for these factors determines the type of resin used, the thickness, and the asperity height of textured or smooth geomembranes.

Testing, testing, testing In AKS’s state-of-the-art laboratory, the company follows strict testing protocols, adhering to and usually exceeding international standards. For example, the US Geosynthetic Research Institute’s GRI – GM13 Standard Specification requires 10 checks for thickness control, while AKS performs as many as 36 checks in 36 zones. In fact, all Geoliner produced by AKS meets or exceeds international standards such as GRI-GM13 (HDPE), GRI-GM17 (LLDPE) and the local SANS 1526. Testing during production is done as a matter of course; continued pinhole

detection is applied across the entire width of the sheet. For added peace of mind, AKS invites customers to a plant visit to familiarise themselves with the integrity and quality standards at work in the company’s modern, easily accessible plant in Brackenfell.

Longevity Along with its excellent impermeability, AKS Geoliner is characterised by its exceptional durability, high chemical resistance, UV protection and superior weldability.

Easy installation The material’s excellent tensile properties and high elongation characteristics combined with flexibility make for a tough barrier that is highly resistant to tearing and puncturing. At the same time, AKS Geoliner is flexible enough to allow for ease of installation without compromising its integrity.

Options Geoliner is manufactured using the calendered ‘flat-die’ extrusion process, in 7 m widths, with thickness ranging from 1 mm to 3 mm. It is available in HDPE and LLDPE, with a smooth or textured finish, or a combination of smooth and textured, either on one or both sides of the sheet. AKS Megatextured Geoliner, offering a more enhanced textured surface, is available in HDPE or LLDPE with either singleor double-side texturing options. To ensure a consistent product with the highest level of accuracy, AKS liners are manufactured using European-made precision extruders. Geoliner can be custom-made to suit specific project requirements, taking into account installation needs, roll lengths, and truck and container loading configurations.

Karlo Wentzel, Sales Manager: Geomembranes, AKS

When it comes to handling – to facilitate off-loading and moving the product on-site – each roll is fitted with two lifting slings.

Traceability An inline marking system ensures on-site quality control and traceability. Instead of relying on a mere sticker or label to identify the brand and batch, a line indicating the wedge weld overlap width – 150 mm from the edge – is printed every linear metre together with the roll number. The number is linked to the AKS quality control system and provides manufacturing information such as the resin used, the master batch, the responsible operator and the MQC certification details. In large installations, the number is entered in a panel layout to provide a record of every square metre of lining used on the site.

Availability AKS Geoliner is manufactured at the company’s modern plant based in Brackenfell, Cape Town. A large yard with ample storage provides the shortest possible lead times to customers. For further information, please email info@aks.co.za or call +27 (0)21 983 2700.

IMIESA October 2020


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Clean power from

Kenya’s Great Rift Valley Franki Africa (a Keller company) recently completed the foundations for a further expansion at Olkaria – the largest geothermal energy producer on the African continent. By Roger Feldmann*


enya’s Olkaria region is par t of a large volcanic complex formed some 25 to 30 million years ago and is located at the axis of the East African Rift situated in the floor of the Great Rift Valley. Violent subterranean forces tore apart the earth's crust in this area and formed active and semi-active volcanoes and lake basins. The geology where the Olkaria geothermal power station is located is characterised by steep-sided domes formed from pyroclastic rock and lava flows. These domes enclose an approximately circular depression that has been cut by the Ol Njorowa Gorge, formed by out-flowing water from nearby Lake Naivasha. Franki was recently appointed to design, install and test the pile foundations for Unit 6, which is the latest addition to the ongoing expansion at Olkaria I geothermal power station. There are currently five active sister power stations in the area (Olkaria I to V), with the construction of Olkaria VI being planned for 2021.

project began in December 2018, and piling commenced in May 2019. Unit 6 adds another 83.3 MW to the grid, bringing the total output capacity at Olkaria I to around 274 MW. A comprehensive geotechnical investigation was completed, and the results formed an integral part of Franki’s ‘design and construct’ solution for the foundations. Franki’s in-house design met the stringent settlement criteria. The design included foundations for the turbine building, cooling tower, hot well, and scrubber areas. Initially a combination of two soil improvement techniques was considered – namely dynamic compaction and rigid inclusions – along with a piled foundation. After careful analysis and taking differential settlement into account, the team finally concluded piled foundations for all the structures would be the most suitable. The ground conditions were conducive to the CFA (continuous flight auger) piling method. The 600 mm Ø CFA piles were designed to withstand loads of up to 1 200 kN, installed to depths of up to 15 m.

Design and construct

Concrete challenges

Development work on Olkaria I’s Unit 6

The mix design is one of the most important

Pile load test under way to confirm pile design and construction

factors to consider for CFA piling projects. As this area is volcanically active, the ground temperature is substantially higher, which resulted in accelerated setting of the concrete placed in the ground. The requirement for full-length reinforcement cages and high-strength concrete, due to the high sulfate content of the ground, created significant challenges in the execution of the project. To ensure that the project progressed smoothly, the Franki site team worked closely with the main contractor, Civicon, to develop a suitable mix design. Careful planning of the site operations was also important to minimise the time between the casting of the pile and cage insertion

Franki working alongside the existing Olkaria I plant in Kenya

IMIESA October 2020



to reduce the possibility of flash-setting. The on-site Franki operations teams were able to achieve high production rates – an excellent achievement considering the challenging and confined site conditions.

Piling in confined access conditions

Stringent testing regime The pile design and loadbearing capacity were further verified by a stringent testing regime, consisting of four static load tests and a pile echo test (PET) on all piles. The static load tests were done according to the test procedure outlined in ASTM D1143-81: 1994, where the piles are loaded in three cycles – i.e. 100%, 150% and finally 250% of the working load. The piles per formed well, and all settlements obser ved were well within the project specifications. “The excellent production and test results achieved reflect the importance of choosing the right pile type to suit the ground conditions,” comments Dr Nicol Chang, technical director at Franki Africa. “The Olkaria project further underscores Franki’s commitment and ability to supply the sub-Saharan African region with quality geotechnical solutions,” adds Chang. *Roger Feldmann specialises in business development at Franki Africa.




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