IMIESA June 2023

www.infrastructurenews.co.za

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

INFRASTRUC TURE DEVELOPMENT • SERVICE DELIVERY • ROADS • BUILDING • MAINTENANCE • ENERGY

WASTE & RECYCLING The intricacies of landfill development

TRANSPORTATION ENGINEERING Intelligent transport designs must be people-centric

WATER & WASTEWATER Inside Joburg Water’s Commando System

APE Pumps & Mather+Platt Locally made pumps engineered for optimum system performance

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Manufacturers,

suppliers and Exporters of : PVC Pipes & Fittings HDPE Pipes & Fittings Steel Pipe & Fittings Valves, Water Meters, & all related products

INSIDE

VOLUME 48 NO. 05 JUNE 2023

36 Regulars www.infrastructurenews.co.za www.infrastructurenews.co.za

IMESA

Editor’s comment

3

President’s comment

5

Index to advertisers

52

WASTE & RECYCLING The intricacies of landfill development

TRANSPORTATION ENGINEERING Intelligent transport designs must be people-centric

WATER & WASTEWATER Inside Joburg Water’s Commando System

APE Pumps & Mather+Platt

Cover Story Pumps made in SA and engineered for optimum system performance

Africa Round-up 8

Information & Communications Technology I S S N 0 2 5 7 1 9 7 8 Vo l u m e 4 7 N o . 0 1 • J a n u a r y 2 0 2 2 • R 5 5 . 0 0 ( i n c l . VAT ) I S S N 0 2 5 7 1 9 7 8 Vo l u m e 4 8 N o . 0 5 • J u n e 2 0 2 3 • R 5 5 . 0 0 ( i n c l . VAT )

ON THE COVER

BIM technologies and GIS: The dynamic duo for transportation

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Transportation

14

TRANSPORTATION

14

e-Micromobility can drive SA cities into the future

17

Can a new approach to tunnelling unlock underground construction potential?

18

22

Y-shaped pylons one of Msikaba’s distinctive features

23

N3 upgrade provides opportunity for innovation

24

Eastern Cape upgrades

24

Waste & Recycling

36 38 39

UCT goes the renewables route to lower energy costs

40

Defining the natural ground level is the foundation for approved development Capacity building and engagement crucial for infrastructure renewal

42 45

Trenchless Technology 46

Cement & Concrete Concrete’s exceptional fire resistance based on unique properties The evolution of green construction Reinstating an industrial floor to a pristine finish

48 49 49

Vehicles & Equipment

The intricacies of landfill development: What’s behind the design?

26

Waste is no longer a forgotten resource

30

WASTE & RECYCLING

34

Renewable Energy & Electrification

Countering micro flooding on Innes Road

Taking the oil out of bitumen

26

Tackling cholera at the source Inside Johannesburg Water’s Commando System Radio monitoring aids in optimising water delivery 10 ways to save water

Planning & Building SA’s Metros

Intelligent transport designs need to be people-centric

Roads & Bridges Standing among South Africa’s leading pump OEMs, APE Pumps and Mather+Platt have built a reputation for excellence based on product innovation spearheaded by dynamic people. IMIESA speaks to John Montgomery, GM for APE Pumps and Mather+Platt, who introduces an up and coming mechanical engineer, Thorne Zurfluh, as a key member of the team. P6

32

Water & Wastewater 6

Locally made pumps engineered for optimum system performance

Infrastructure news from around the continent

31

Infrastructure Funding & Implementation 40 years of DBSA development progress

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

INFRASTRUC TURE DEVELOPMENT • SERVICE DELIVERY • ROADS • BUILDING • MAINTENANCE • ENERGY

Illegal tyres pose a pollution and road safety risk

Class-leading trommels added to ELB line-up Island runway rehabilitation

46

TRENCHLESS TECHNOLOGY

51 52

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EDITOR’S COMMENT MANAGING EDITOR Alastair Currie SENIOR JOURNALIST Kirsten Kelly JOURNALIST Nombulelo Manyana EDITORIAL COORDINATOR Ziyanda Majodina HEAD OF DESIGN Beren Bauermeister CHIEF SUB-EDITOR Tristan Snijders CONTRIBUTORS Hans Kaderli, Patrick Lane-Nott, Chetan Mistry, Sibusiso Mjwara, Zeph Nhleko, Andile Skosana, Altus Strydom, Shuaib Yunos PRODUCTION & CLIENT LIAISON MANAGER Antois-Leigh Nepgen GROUP SALES MANAGER Chilomia Van Wijk DISTRIBUTION MANAGER Nomsa Masina DISTRIBUTION COORDINATOR Asha Pursotham SUBSCRIPTIONS subs@3smedia.co.za ___________________________________________________ ADVERTISING SALES KEY ACCOUNT MANAGER Joanne Lawrie Tel: +27 (0)11 233 2600 / +27 (0)82 346 5338 Email: joanne.lawrie@3smedia.co.za ___________________________________________________

PUBLISHER Jacques Breytenbach 3S Media Production Park, 83 Heidelberg Road, City Deep Johannesburg South, 2136 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 2023. 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 EASTERN CAPE Secretary: Susan Canestra Tel: +27 (0)41 585 4142 ext. 7 Email: imesaec@imesa.org.za KWAZULU-NATAL Secretary: Narisha Sogan 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 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. _____________________________________________ Novus Holdings is a Level 2 BBBEE Contributor: novus.holdings/sustainability/transformation

The ABC logo is a valued stamp of measurement and trust. IMIESA is ABC audited and certified.

The quest for citizen-centric municipal leadership

T

here’s no doubt that South Africa’s economy is under pressure, with the construction sector being one of the most underinvested. This is despite the fact that it is the foundation for any meaningful change in terms of industrial development, allied job creation and much-needed social infrastructure.

Aside from the private sector investment we need to make positive gains, the improved performance of the public sector is vital to ensure that government policies are aligned with market influences that will promote micro- and macroeconomic development.

At the coal face, municipalities remain the essential community interface for the enabling environment needed to make this work, backed by national and provincial government funding, where applicable.

The latter comment is made on the basis that municipalities must and should function as independent and profitable entities in terms of their operating mandate.

When it comes to recruitment and selection, only the best civil servants should hold positions of office. That must be a priority for government and municipalities in attracting exceptional talent and ensuring that all outcomes are performance based, with salaries in line with the same or similar skills in the private sector.

Coalitions A thorny issue is the widespread evolution of the coalition government model at municipal level. While it arguably promotes democracy, erratic changes in mayoral leadership due to competition within political parties hampers the effectiveness of sustainable social and interrelated infrastructure planning. With the possibility of a similar cabinet coalition model emerging following the 2024 National Elections, policymakers need to ensure that there are sufficient checks and balances. Team South Africa comes first.

Local government audit outcomes Positive gains in this respect within the municipal

space are being spearheaded by the AuditorGeneral (AG) South Africa’s office, led by AG Tsakani Maluleke. Referring to the latest 2021-22 MFMA consolidated general report on local government audit outcomes, she called on all South Africans to be “active participants in helping improve accountability and to hold local government accountable.”

More specifically, she referred to “…citizen-centric municipal leadership.” That makes perfect sense because the rates and taxes paid by households and business are meant to facilitate municipal operations and create a reserve for planned maintenance upgrades and new infrastructure.

For the year under review, there was an estimated expenditure budget of R487.12 billion scheduled by municipalities to operate and deliver services. That’s a substantial amount of money, despite these tough economic times, and a number of municipalities did demonstrate competent leadership and execution.

But not enough to make a difference overall.

Out of 257 municipalities, only 15% – accounting for some 29% of the total municipal expenditure budget – achieved an unqualified with no findings (essentially clean) audit. So, there’s room for improvement. And the AG also emphasised that when “political transition occurs, the administrative functions must continue to fulfil their duties” going forward.

The shining metro stars for 2021/22 were the cities of Cape Town and Ekurhuleni.

Then from a provincial perspective, the Western Cape led in terms of the most municipalities that scored clean audit options. This demonstrates that exceptional local government performance is possible and happening, but not on the scale yet that we need to make South Africa function optimally.

Alastair 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.

www.infrastructurenews.co.za

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

@infrastructure4

Infrastructure News

INFRASTRUC TURE DEVELOPMENT • SERVICE DELIVERY • ROADS • BUILDING • MAINTENANCE • ENERGY

WASTE & RECYCLING The intricacies of landfill development

TRANSPORTATION ENGINEERING Intelligent transport designs must be people-centric

WATER & WASTEWATER Inside Joburg Water’s Commando System

APE Pumps & Mather+Platt Locally made pumps engineered for optimum system performance

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Cover opportunity

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 June 2023

3

HAVE YOU REGISTERED FOR THE IMESA CONFERENCE YET?

Register today.

Take advantage of the EARLY BIRD RATE and SAVE! EVENT: 86TH Imesa Conference DATES: 25-27 October 2023 VENUE: Boardwalk Hotel, Gqeberha (PE) THEME: Resilience is the future

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IMESA ORGANISER

THE INSTITUTE OF MUNICIPAL ENGINEERING OF SOUTHERN AFRICA (IMESA)

PRESIDENT’S COMMENT

IMESA

ENVIRONMENTAL FALLOUTS NEED AN ENGINEERED RESPONSE Water and sanitation are two areas of the human experience that cannot be compromised, which is why they feature prominently as one of the UN’s 17 Sustainable Development Goals (SDG).

T

his underscores the evidence that there are major infrastructure gaps – especially within developing countries that need to respond to a massive surge in population growth and intensified urbanisation trends.

Complicating the problem is the constant and intensifying climate change threat that brings with it extreme weather conditions thanks to phenomena like El Niño and La Niña. The latter are cyclical climate patterns influenced by the unusual warming or cooling, respectively, of surface waters in the eastern Pacific Ocean. Together, they form part of the broader El Niño-Southern Oscillation (ENSO) that influences atmospheric circulation around the globe.

Weather predictions According to local and international experts, there’s a fair chance of a ‘moderate-to-strong’ El Niño occurring in 2023. The last major spike was the 2015/16 El Niño, which exceeded previous warming records. It was almost certainly a factor in Cape Town’s protracted drought between 2015 and 2018.

Now we need to be prepared for another potential extreme weather season for 2023/24. Either way, the 2022 eThekwini floods and the ongoing Nelson Mandela Bay drought crisis are clear evidence that global warming is taking its toll on the environment, and we need to be far more proactive in its mitigation.

Infrastructure and pollution That in turn speaks to South Africa’s infrastructure challenges. Soil erosion, caused by poor land management practices, is exacerbating flood damage due to incidences like ground collapses. Siltation is another serious factor as soil enters rivers and builds up behind dam walls, significantly reducing their designed storage capacity and life.

At the business end, another key concern is the substantial backlog in addressing ageing pipeline infrastructure, compounded by available budget constraints and in-house engineering skills to address the problem.

The result is that non-revenue water losses are too high – averaging around 40% in South Africa nationally. Then there are the environmental contamination threats posed by leaking sewer lines. In addition to groundwater pollution scenarios, there’s a real risk of sewage entering cracked potable water lines during periods of intermittent supply.

The latter practice typically occurs when municipalities and utilities are forced to impose water restrictions during drought periods. Since potable water pipelines are pressurised, this stop/start process can inadvertently suck in pollutants that could pose a health risk to consumers and, in severe cases, cholera.

Sibusiso Mjwara, PrTechEng, MIMESA, MSAICE, MWISA, MIPET

At the upper catchment level, increased rainfall also contributes to higher run-off of leaking sewage, which eventually finds its way to rivers. When abstracted, this polluted water increases the treatment costs for water utilities and municipalities, and subsequently increases tariff costs for consumers.

This situation is further compounded by the fact that a higher than acceptable percentage of municipal water and wastewater treatment works perform suboptimally – as indicated by recent Blue and Green Drop reports issued by the Department of Water and Sanitation. This means that effluent discharged to the environment is often not treated to standard, promoting a vicious cycle of spiralling pollution and process costs.

A need for homegrown innovation However, rather than seeing these environmental and infrastructure challenges as insurmountable, we must embrace them as opportunities for positive socio-economic change as we reengineer in line with the broader SDGs. We have most if not all of the capabilities and skills we need right here in South Africa.

Our leading universities and academic community are on par with the best worldwide.

And we have a sound manufacturing base, plus rapidly growing tech industries.

So, while it’s important to study global benchmarks, we need to focus more on promoting local innovation that translates into ‘Made in RSA’ goods, technologies and applications. Examples would include desalination, the default use of trenchless technologies in urban areas for upgraded and new pipeline installations, alternative building techniques using recycled materials, mainstream renewable energy on demand, and a booming local electric vehicle manufacturing sector.

Equally important is ongoing education at schools and within communities on why we need to respond to South Africa’s countryspecific SDG challenges together. That’s the best way to gain the buy-in we need from all stakeholders to re-engineer the future and clean up our environment.

IMIESA June 2023

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COVER STORY

Pumps made in SA and engineered for optimum system performance

Standing among South Africa’s leading pump OEMs, APE Pumps and Mather+Platt have built a reputation for excellence based on product innovation spearheaded by dynamic people.

IMIESA speaks to John Montgomery, GM for APE Pumps and Mather+Platt, who introduces an up and coming mechanical engineer, Thorne Zurfluh, as a key member of the team.

A

PE Pumps is 71 years old in 2023, while Mather+Platt is much older, tracing its roots back to the First Industrial Revolution from the mid-18th century, where from the dawn of industrialisation pumps have been and remain the critical interface for every aspect of fluid transfer. Both OEM bands cater for fit-for-purpose applications in key sectors that include water and wastewater, firefighting, energy, mining, agriculture and the petrochemical sector.

Over the years, APE Pumps and Mather+Platt (the group) have ensured their success through succession planning, market diversification and investment in specialist technologies to support business growth. (Both sister entities form part of the multinational WPIL Limited group of companies.)

Montgomery started his career with these two leading brands some 19 years ago as a qualified draftsman. Over the years, he has been exposed to every facet of the business – from design to production, stripping and assembly, and installation. It’s a complex field.

6 IMIESA June 2023

expansion into key services that include customer service-level agreements (SLA) for operations and maintenance (O&M) on the group’s own installed systems. As a CIDB 8 ME contractor, the group is further expanding its EPC services to include turnkey design, fabrication and commissioning.

This presents the need for qualified engineers as part of the group’s technical team capabilities.

“I previously worked for an EPC consulting company specialising in steel construction. It opened my eyes to the intricacies of project and programme management, and how important the details are in delivering the exact solution and seeing the final structure take shape,” says Zurfluh.

“That’s why I wanted to become a mechanical engineer: to experience raw metal translated into state-of-the-art functioning systems – in this case, pumps. This has always been my lifelong ambition, and now I get to do it on a daily basis. Allied to this, my structural steel EPC exposure adds valuable input on the group’s turnkey contracting projects. Pumps don’t function in insolation – they need integral installation to suit applicationspecific outcomes,” Zurfluh continues.

Computational fluid dynamics

“Clearly, no pump engineer, specialist technician or artisan is born overnight. The baseline skills are essential, but the experiential, applied learning is what defines master craftsmen, engineers and project managers in all our interrelated disciplines. That’s why our business is dedicated to attracting and mentoring the best talent available, which is why we brought Thorne on board in June 2022 to be trained as one of our next-generation leaders. We like a two-way mentorship approach, where the ‘old’ teach the ‘young’ and vice versa, in modern versus tried and tested techniques,” explains Montgomery.

Evolving engineering focus Currently studying his MBA at Wits Business School, Zurfluh joins the group at a time of unprecedented growth in production demand, as well as parallel

Group software investments include an industryleading CFD (computational fluid dynamics) simulation program that enables the engineering team to model and interrogate new pump designs, pump retrofits and upgrades, as well as the analysis of flow behaviour in a new or existing system.

“For example, we can simulate the implications of installing new pump manifolds and determine the envisaged pressure drop, the pipe sizing requirements, etc. We can also import other 3D design data to build the working digital model,” Zurfluh explains.

He also points out that adopting a holistic approach is important in achieving the best performance. For a bulk water transfer scheme, for example, any current or future network upgrade must factor in anticipated urban expansion and population growth. That means Thorne Zurfluh, mechanical engineer, APE Pumps and Mather+Platt

selection and optimisation are crucial in terms of return on investment and life-cycle costing.

Forecasting future plant upgrades is equally important to ensure that pump rooms have space for additional units at a later stage, or that treatment works can be expanded when they reach their current design capacity. In turn, strict condition monitoring and maintenance regimes are essential – solutions provided by the group’s O&M services.

For clients, the major benefit of signing an SLA is that O&M becomes an outsourced solution undertaken by an expert OEM with full parts inventory backup. That translates into fast turnaround on scheduled maintenance, and reduced breakdown times due to predictive and preventative maintenance. Routine on-site inspections are performed using advanced vibration and laser alignment tools for ongoing condition monitoring.

There’s also a growing demand from clients for energy-efficient designs. “The common request increasingly asked by utilities and municipalities is how they can lower electricity costs while still maintaining bulk demand targets. So, there’s a big shift in how we do the pump and electric motor selections since, over the years, the electricity cost to run a pump far outweighs its initial acquisition and commissioning cost,” says Zurfluh.

Manufacturing investments At the heart of the process is the group’s manufacturing capabilities, with a core specialisation in custom builds and an ongoing investment in new machines and tooling to

also has a pump exchange programme for mission-critical sites, like power stations, where downtime must be reduced to a minimum.

Legacy drawings and the 3D world ensure that the fabrication lines can run on a 24-hour basis, when required. As Zurfluh explains, the objective is to make sure that the group is self-sufficient in terms of production and quality control.

Recent acquisitions include: an 8 m long lathe with a 1.4 m swing, specifically for circulating water pumps; a 12 t CNC horizontal boring machine; a 2.5 m vertical boring machine; and what is believed to be the second largest key slotter machine installed to date in South Africa, which will be used for large impeller fabrication.

Production focuses on new pump fabrication, upgrades and complete overhauls. The group

Significantly, and as a long-established OEM, the group has retained the drawings for every single pump brand produced from inception.

Traditionally, these have been 2D drawings with the measurements painstakingly replicated by hand by the group’s patternmakers to create the casting mould. Now, APE Pumps and Mather+Platt have taken this a step further by recently investing in the latest 3D scanning technology, which achieves a 0.02 dimensional accuracy. The same result or similar was being achieved with the manual method, but it took a lot longer.

If it’s a complete rebuild, the manufacturing team can now scan the original, make a pattern, manufacture it, scan the new one, and then compare the two in a digital overlay for verification. This scanning technology can also be used for quality control to check for key aspects like perpendicularity, concentricity, parallelism, and shaft runouts.

Conclusion Montgomery adds: “As industry pioneers and early adopters of technology, we’ve stayed the course for seven decades in South Africa because we’ve remained relevant, with an unwavering commitment to customer service.

“Bringing new talent onboard, like Thorne, is part of our sustained investment in human capital – a forward-thinking approach that continues to position us as an OEM leader and specialist turnkey contractor in the fluid transfer field,” he concludes.

www.apepumps.co.za www.matherandplatt.com

IMIESA June 2023

7

INFRASTRUCTURE NEWS

FROM AROUND THE CONTINENT

TUNISIA PPP contract to improve wastewater management services The Tunisian government and the World Bank signed a €113.6 million (R2.25 billion) loan agreement for funding to be allocated to the Tunisia Sanitation Public-Private Partnership (PPP) Support project. The primary objective of this initiative is to strengthen the capacity of the national sanitation public company (ONAS) to effectively manage PPP contracts related to the provision of sanitation services.

In many regions in Tunisia, access to water supply and sanitation services remains a challenge. Despite substantial progress in improving access to water supply and sanitation services, about 360 000 people are still using unimproved sanitation services. While most of the population without access to sewerage live in rural areas, the wastewater generated by more than 1.7 million urban residents remains untreated. In addition, 2020 records show that 24% of wastewater treatment plants managed by ONAS were operating beyond their hydraulic capacity.

To address these challenges, and with technical support from the International Finance Corporation (IFC), a member of the World Bank Group focused on the private sector, the Tunisian

Government has encouraged ONAS to develop PPPs through regional public service delegation contracts. These PPPs will help ONAS access quality and efficiency gains associated with private sector service delivery and compare the results with its operations.

“This project will support improved water supply and sanitation services for an estimated two million direct beneficiaries – more than 500 000 households – during the 10 years of implementation, with around half being women and girls. Given its long-term involvement in the sector and the continuous support provided to ONAS, since its creation in 1974, through eight World Bank-financed projects, the World Bank is well placed to support this initiative,” says Alexandre Arrobbio, country manager: Tunisia, World Bank.

KENYA Menengai geothermal project breaks ground Construction has begun on the US$108 million (R1.96 billion) Menengai Project through a partnership between Geothermal Development Company (GDC) and Globeleq. The project aims to deliver clean, reliable and affordable baseload power to the Kenyan national grid. GDC will monetise the available steam resources from the Menengai steam field and Globeleq will operate and maintain the power plant once it reaches commercial operations in 2025.

Menengai is a greenfield geothermal project and part of the first phase of

the wider Menengai complex, which is the second large-scale geothermal field being developed in Kenya after Olkaria. Steam will be supplied to the project by GDC under a 25-year project implementation and steam supply agreement. Once the plant is operational, electricity will be sold to Kenya Power, the national distribution company, under a power purchase agreement for the same timeframe.

Toyota Tsusho Corporation from Japan is the EPC contractor to the project.

Fuji Electric will be manufacturing and supplying the steam turbine and generator.

NAMIBIA Citizens use emergency borehole water With dams running dry at a rapid rate, the City of Windhoek has resorted to supplementing the capital’s drinking water supply through its emergency borehole scheme. This follows after the city council decided to implement water restrictions as part of its drought response plan.

Certain neighbourhoods will only receive borehole water, while others will receive a mixture of borehole and municipal water.

This water supply strategy will remain in place until noticeable inflows are received from the NamWater surface sources.

8 IMIESA June 2023

The total average level for Windhoek’s three water supply dams currently stands at 34.6%, in comparison to last season’s total level of 57.1% during the same period.

According to NamWater’s latest dam bulletin, the Swakoppoort dam’s level is still at 67.2%. The level of the Von Bach Dam is at 22.8%, and the Omatako Dam is empty.

However, the city has said that it is important to note that the dam’s water is of poor quality and that the transfer system that links to Von Bach Dam is very unreliable, suffering from regular interruptions.

TRENCHLESS TECHNOLOGY | SEWER REHABILITATION COVER STORY

MOZAMBIQUE Eskom to receive 100 MW of electricity South Africa will receive 600 MW in the next six months and 1 000 MW in the long term through Mozambique’s Cahora Bassa hydroelectric power plant.

The assistance from Mozambique is one of the measures that Eskom and the Ministr y of Electricity have looked into following advisor y and model programmes from other countries that have created stable power grids.

The Cahora Bassa Hydroelectric Complex has been in operation since 1975 and comprises a variety of engineering infrastructures – the hydroelectric power station, the Songo conver ter substation, the HVDC and HVAC transmission lines, and the Matambo substation – enabling the production, transmission and commercialisation of energy.

ANGOLA Record loan for renewable energy The Expor t-Impor t Bank of the United States of America (US Exim Bank) is providing a US$900 million (R16.38 billion) loan to the Angolan government to suppor t the construction of two solar photovoltaic power plants with a combined capacity of 500 MWp. The project to build these two solar farms is an initiative of the Angolan government in par tnership with the American companies AfricaGlobal Schaffer and Sun Africa. Sun Africa has pledged to invest $1.5 billion (R27.3 billion) in Angola’s water and energy sectors from 2021. With an office already set up in the Angolan capital, Luanda, Sun Africa aims to make these investments in the southern provinces of Cunene, Namibe, Cuando Cubango and Huíla.

This Washington-based financial institution is also providing the financing as par t of the China and Transformational Expor ts Program (CTEP) – a programme mandated by the US Congress to suppor t American expor ters facing competition from China.

In the solar market, Chinese companies are leading the way, supplying equipment throughout Africa and elsewhere in the world. The largest solar power plants in operation, or currently under construction, notably in South Africa and Egypt, are equipped by Chinese manufacturers.

This is the case of the Kom Ombo solar power plant, whose modules will be supplied by LONGi. When it comes to solar energy, China is by far the biggest market, with 174.8 GW of installed capacity in 2018, and supplies 60% to 70% of the world’s solar panels, according to the Futura-Sciences platform. Angola, which is banking on this energy to develop its economy, is 56% dependent on hydroelectricity (out of an installed capacity of 6 143 MW).

IMIESA June 2023

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INFORMATION & COMMUNICATIONS TECHNOLOGY

BIM TECHNOLOGIES AND GIS:

The dynamic duo for transportation Building information modelling (BIM) is an intelligent process that gives architecture, engineering and construction (AEC) professionals the insights and tools needed to more efficiently plan, design, construct, and manage buildings and infrastructure, housed within a common data environment (CDE).

These BIM technologies can be incorporated with geographic information systems (GIS) for fur ther insight and intelligent planning. By Shuaib Yunos

B

IM is a rapidly evolving methodology that has already become mainstream within the AEC community globally; in South Africa, however, it’s still new territory for many, with most professionals adopting the BIM technological component from the BIM process.

For this reason, and as a senior BIM technical specialist, I often need to respond to questions when planning and conceptualising projects, particularly in the field of transportation.

The following are common questions and responses.

FIGURE 1 A simple example of an avoidance zone (red) added along a roadway generated using computational analysis (Source: Created by Shuaib Yunos in Autodesk Infraworks 2024)

GIS, we can use the power of computational analysis to derive the most suitable route incorporating multiple contributing factors, like those mentioned.

By linking GIS databases, we can also determine existing services that inform the design of the transportation corridor and the linking of new services. By applying computational analysis, the various corridors derived can then be scrutinised to arrive at a corridor that’s most suited in terms of economy, sustainability and function. (Figure 1)

What would the corridor look like?

Here, the advantage of 3D visualisation provided by BIM technologies comes into play.

Realistic renders and animations, including virtual, augmented reality and gamification, can be produced to envisage the environment or concept, allowing clients to interrogate factors such as safety, urban suitability and aesthetics.

(Figure 2 & 3)

How would traffic and people interact?

Here we can create traffic and mobility analyses to examine the behaviour. We can simulate people walking along the sidewalk, queuing and

FIGURE 2 Snapshots from the A303 Stonehenge Road model (Source: Winchester, H. 2020)

Which is the optimal route?

Determining where to start and/ or end a transportation corridor is tricky, as these corridors traverse areas of varying elevations, environmental categories, services and land value. However, with BIM and Shuaib Yunos, senior BIM technical specialist: Civil Infrastructure & Mining, Baker Baynes

10 IMIESA June 2023

INFORMATION & COMMUNICATIONS TECHNOLOGY

FIGURE 3 Tunnel BIM and gamification model (Source: Autodesk Customer Success Stories 2017, Norconsult)

accessing public transport, as well as the flow of traffic based on specified factors to gauge realistic impacts. (Figure 4)

What about bridges and tunnels?

Bridges and tunnels are critical components in transportation corridors and can be incorporated and linked thanks to BIM technology workflows. The parametric nature between geometric and structural industries effectively synchronises these infrastructure elements, ensuring a dynamic link. Furthermore, the flexibility afforded promotes innovation and customisation, enabling professionals to provide futuristic solutions. (Figure 5)

What about existing services and utilities below ground?

With the advantage of GIS, these services can be imported into the model and, with the beauty of 3D visualisation, we can view these elements below ground in their 3D parametric nature. The metadata attached to GIS database elements will inform the positioning and information attached to each object. (Figure 6)

Where do I find reliable, accessible GIS data?

This is always a tricky question, particularly in South Africa and the African continent in general. Your best bet would be to source GIS data from municipalities, normally shared in a .shp file format. Your

FIGURE 4 Mobility simulation example comprising people and traffic (Source: Mobility Simulator for InfraWorks 360. Autodesk 2016)

second option would be to source data from a service provider or online sources. Just ensure you check the credibility and last update date of the online source. This data can be free or purchased.

Everything sounds great, but what about costing and quantification?

Due to the parametric prowess of BIM, quantities can be derived from the concept. This data is accurate and derived directly from

INFORMATION & COMMUNICATIONS TECHNOLOGY

FIGURE 5 Example of a parametric bridge and tunnel created using BIM technologies (Source: Created by Shuaib Yunos in Autodesk Infraworks 2024)

recognised format such as IFC. IFC is the acronym for Industry Foundation Classes, an open format that allows professionals to collaborate and share their designs across various vendors. The focus of openBIM is on the data and not the vendor.

Final thoughts

the parametric properties of model elements.

These quantities can then be assigned a unit price, resulting in a well-informed project total, even as early as the planning and conceptual stage. These values can then be further interrogated and finalised upon detailed engineering design.

Will I need to start over when I get to detailed engineering design?

BIM overcomes the silo effect experienced in conventional project workflows. This means your planning data can be linked/imported into the detailed design phase, promoting the reuse of data and reducing rework.

Bonus – you can then link your detailed/final engineering design back to generate a final visualisation of your corridor!

Can I bring in designs from other disciplines such as architecture?

Yes, you can! On transportation corridors, especially railways and bus rapid transit (BRT) systems, the stations are a key part of the project. These can be imported into your design – just ensure that the model is coordinated correctly to the correct positioning per the coordinate system you are working in. (Figure 7)

How do file integrations work across software vendors?

I always suggest working within a certain ecosystem of technology (i.e. technology vendor) on projects, as it reduces or negates this risk of interoperability. But in cases where this is unavoidable, what then? This is where openBIM comes into play.

In simple terms, openBIM uses a global standard of data exchange that is vendor agnostic. This means that every true BIM software program must export to an industry

BIM technologies and GIS really are the dynamic duo in the civil infrastructure industry, changing the way we plan, design, construct and maintain infrastructure assets.

And this is just looking at the component of basic technology in the BIM ecosystem. (Don’t get me started on the power and automation provided by computational design and visual scripting.)

When BIM is truly adopted within a CDE platform, and in accordance with international standards (like ISO 19650), it provides an unprecedented way of working. AEC professionals can manage assets, and effectively plan and coordinate the expansion of services and infrastructure within the realm of the physical and virtual world. The BIM model can then be extended in use, fulfilling the role of an asset in the form of a digital replica in the digital twinning process, ultimately aiding the pursuit of smart cities and infrastructure.

By digitally transforming our processes, we unlock possibilities to create infrastructure landmarks that are built to last, creating a better future for all.

SOURCES 1. Autodesk. 2016. Mobility Simulator for InfraWorks 360 (online video).

Available: https://www.youtube.com/ watch?v=2BSiHct6N9I&t=18s 2. Autodesk Customer Success Stories.

2021. HHO BRT Station, Visualising Tough Engineering Challenges with Autodesk. Available: https://www. autodesk.co.za/customer-stories/hho

FIGURE 6 Example of GIS data visualised for a stormwater network in 3D below ground (Source: Bartels, J. 2017)

3. Autodesk Customer Success Stories.

2017. Norconsult Infrastructure innovators use VR Games to Streamline Scandinavian Tunnel Design. Available: https://www.autodesk.com/customerstories/norconsult-vr-gamification 4. Bartels, J. 2017. Using SHP Files to Model Underground Utilities in InfraWorks (online video). Available: https://www.youtube.com/ watch?v=6DfUa1Vz39o

FIGURE 7 Station with people and vehicles on a BRT project in Sandton (Source: Autodesk Customer Success Stories HHO Consulting Engineers, 2017)

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5. Winchester, H. 2020. How AECOM is Paving the Way Forward with V-Ray. Chaos. Available: https://www.chaos. com/blog/how-aecom-is-paving-the-wayforward-with-v-ray

86

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TRANSPORTATION

INTELLIGENT TRANSPORT DESIGNS NEED TO BE PEOPLE-CENTRIC Optimising traffic flows and improving access to multimodal transport are two key elements in smart mobility solutions. To achieve meaningful integration, however, they must be practical and affordable. Alastair Currie speaks to Mike van Tonder (MvT), Expertise Leader: Transport Planning and Intelligent Transport Systems at Zutari, about trends and developments.

How would you define smart mobility?

MvT Smart mobility is an all-encompassing description of new or improved ways of moving people and goods around. It can mean new technologies that improve the efficiency of mobility or access, as well as the use of new modes of mobility that have not previously been used, such as drone taxis, robotic deliveries, e-scooters and e-bikes.

From our experience, each country also has a unique definition of smart mobility depending on what stage the country is at in its smart city development journey. We have seen this on projects that Zutari has worked on in diverse cities from Durban to Dubai. For example, cities like Dubai, Hong Kong, London, Seoul and Singapore have very mature world-class transport infrastructure, and they have the resources to invest extensively in smart city technologies that enable smart mobility.

GO GEORGE’s integrated public transit network system serves the community

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Smart mobility is not just about mobility technology; it is about accessibility to mobility, the efficiency of mobility, mobility integration, sustainability, costeffectiveness and quality of the journey. A prime example is bus rapid transit (BRT), which has been successful in countries like Colombia and Brazil and is being rolled out in several cities in South Africa.

Local examples where Zutari is or has been involved in BRT projects include MyCiti in Cape Town, GO!Durban and GO GEORGE. The latter is not a pure BRT system, but rather an integrated public transit network (IPTN) that does not have its own right-of-way (lanes); it is an integrated service that works on the same principle. The differentiator for BRT networks is that they are much cheaper than a rail network, but can still provide high-capacity transit to a point.

In South Africa, the IPTN and integrated rapid public transit network (IRPTN) systems also have integrated fare management systems that use an

Mike van Tonder, Expertise Leader: Transport Planning and Intelligent Transport Systems at Zutari

EMV-compliant tap-on/tap-off smart card to improve the experience of the journey.

Other intelligent transport systems (ITSs) typically used in BRT networks include advanced public transport management systems (APTM, CCTV and automated incident detection systems), passenger information systems like apps and websites, and fault management

GO GEORGE’s integrated fare management system uses an EMV-compliant tap-on/tap-off smart card to improve the journey experience

systems. More advanced BRTs also have journey planning systems.

An important success factor for BRTs in South Africa is that the minibus taxi industry needs to be incorporated into the integrated BRT system in one form or another. The minibus taxi industry transports millions of passengers every single day in South Africa, and they need to be part of any integrated solution. The role of the industry can vary from being part of the BRT operator to other service providers to the system – like station and bus maintenance – to providing feeder transport services to the main line trunk route. It is, however, imperative that they are involved.

In order to achieve this full integration of the BRT, and if minibus taxis are to be used as part of the solution, then the minibus taxi industry needs to migrate to a digital environment. They need to move from a cash-based fare payment system to a tap-and-go, card-based payment system, incorporate CCTV cameras in the ranks and vehicles, and implement elements like real-time vehicle tracking (GPS location), and eventually move to some form of scheduling.

The industry has already started this digital transformation, with some associations installing CCTV cameras in their vehicles and owners actively tracking their vehicles.

Many cities are also assisting the industry by introducing CCTV cameras, number plate

recognition technology at ranks, and incentives for improved driver behaviour.

What are some of the key smart mobility trends worldwide?

Some of the key trends globally include connected and autonomous vehicles. In Africa, at present, we’re mainly seeing this trend in closed or controlled environments, like a railway system, port environment or a mine environment, where the general public does not have uncontrolled access. In my view, South Africa is still a long way off in terms of general public or private user applications of autonomous vehicles. However, in developed regions in Europe, Asia and the USA, adoption is already well advanced.

Other key trends include artificial intelligence, natural language processing, big data and machine learning. These are able to provide predictive information about a transport system or service where commuters can make informed decisions about an upcoming journey. Using this information from artificial intelligence, a commuter can choose, for example, the fastest, cheapest or most comfortable trip.

Then there’s mobility as a service (MaaS).

Examples include e-hailing like Uber in South Africa and e-scooter and e-bike hire in other countries – taking this a step further is

shared mobility, which is becoming popular in regions like Europe. Here, an e-hailing vehicle can be booked and shared by several passengers from an area, heading in the same or a similar direction.

Another very popular development internationally is the introduction of single account-based payment services to enable passengers to plan, book and pay for multiple types of mobility services for single journeys, only paying once. For example, a traveller could hire an e-scooter from home to the train station (first mile), then travel to the airport by train, fly to the arrival destination, catch a bus at the arrival destination to the city centre, and from there hire an e-bike to the final destination (last mile), using one booking platform.

Another very popular trend internationally is the user-pays principle, used by governments to manage or influence travel and transportation. An example would be making city centre parking premium priced at peak times to discourage private car usage during these periods. Variable toll road systems are another example for transport demand management.

There is a definite move towards delivering customer-centric mobility services.

Increasingly, engineers and planners are no longer dictating what type of transport services they need to provide but are using

IMIESA June 2023

15

TRANSPORTATION

implementation by government needs to be balanced against other needs.

Can we use smart mobility to lower our carbon footprint?

The use of e-scooters and e-bikes in cities like Dubai is becoming very popular for first- and last-mile trips

what the customer wants to plan and design for transportation services and infrastructure.

Customer satisfaction is vital to achieve optimal results for any smart mobility solution. These days, if a customer doesn’t like a particular transport service or infrastructure, they will not use it because they have other options.

How do smart mobility and smart city concepts best interconnect?

Unless it’s a greenfield development built from scratch, the reality is that smart city evolution begins with the progressive phasing in of smart technologies one step at a time. Traditionally, mobility and smart transport has always been the starting point. However, other sectors like energy and water are rapidly catching up with the transition to smart control, metering and payment services.

We are also seeing apps take on far greater prominence in terms of infrastructure management. A prime example is Joburg’s pothole repair app where Discovery Insure, in partnership with Dialdirect and the City of Johannesburg, has launched a metrobased initiative spearheaded by their Pothole Patrol programme.

Then from a traffic management perspective, Sanral has freeway management systems (FMSs) operating in Gauteng, KwaZulu-Natal and the Western Cape, and is busy rolling out

16 IMIESA June 2023

a similar system in the Eastern Cape. These are all monitored and managed from a central traffic management centre (TMC) and include maintenance and operations of the systems.

Within the metros, where Sanral networks interconnect with the provincial and municipal road network, local TMCs are either integrated with Sanral’s or are incorporated into the TMC. In Cape Town’s case, for instance, some 150 km of Sanral’s freeway are co-managed with the city and monitored by an extensive CCTV system that reports real-time data.

Zutari, as part of the Tolcon consortium, is currently working on Sanral’s FMS in Gauteng, where we are rolling out additional CCTV cameras and planning to upgrade existing variable messaging signs. A new state-of-theart video wall has also just been installed at the N1 TMC in Samrand.

What type of ICT infrastructure is required now and in the future?

Fibre and 5G cellular communication are the backbone for any ITS. In South Africa, the private sector has been very proactive in implementing fibre and cellular networks nationally, and our communications infrastructure is on a par with the best. So, the network is in place, along with the rapid expansion of the data centre industry, to support cloud-based computing.

Implementation, though, depends on government priorities, especially given South Africa’s triple challenges of inequality, unemployment and poverty. Any ITS

Yes, because it is an opportunity to bring so many factors into play. We know that new conventional diesel and fossil fuel combustion engines will be with us until at least 2035 in the UK and Europe in terms of their cut-off targets. Thereafter, only used derivatives will be available, and no new ‘fossil fuel’ powered engines sold.

Going forward, electric vehicles will be the norm and clients recognise this. Our current work for the University of Cape Town is a case in point, where the plan is to transition the student bus fleet to EVs in the future.

Thanks to South African companies like GridCars, which is investing in national charging stations, EVs are much closer today to becoming one of the mainstream power solutions for private and commercial transport.

At present, the debate internationally is about which charging option works best. Some argue for battery swop-outs (like China), which makes a lot of sense on a longer trip – say from Cape Town to Johannesburg – but it would appear that charging infrastructure at key locations is more common. Also, imagine a scenario where our minibus taxis are all EVs. It seems incredible now, but it is more likely than you think.

The major turning point will come when EVs start to be manufactured in South Africa.

At present, all EVs that have to be imported attract massive import duties. That has to change, with South Africa’s automotive sector leading the charge and government becoming the enabler for cheaper EVs. In South Africa, e-scooters could immediately change the landscape for urban commuters by introducing a clean and very affordable mode of transport. The use of e-scooters in cities like Dubai is becoming very popular for firstand last-mile trips, so why not here in South Africa where we are already seeing e-trikes being used by supermarkets for neighbourhood grocery deliveries?

And in closing?

In the past, many countries, especially developing ones, felt that the cost of smart mobility and smart city implementation was just too expensive. However, the cost of ICT technology is steadily coming down, which is definitely helping to promote wider adoption, because the socio-economic benefits are significant.

TRANSPORTATION

e-Micromobility can drive SA cities into the future The world is rocketing ahead into an era of sustainability that spans the realms of renewable power generation, e-mobility, green buildings and consumption habits, among much more.

By Andile Skosana, CEO, CityConsolidator Africa

W

hile other countries are leading the charge with electric vehicles (EVs) and renewable energy, South Africa is languishing in a power crisis, which makes the thought of EVs on a mass scale seem like a pipe dream.

Pipe dream or not, the revolution is coming, and South Africa will have no choice but to keep up – both for its own competitiveness and for the health of our environment. The ideal is a country, and cities, that are built around sustainability and e-mobility, and, we would strongly argue, e-micromobility.

But the question is how do we get there?

We believe fervently in the power of policy to positively impact society. CityConsolidator Africa’s DNA is rooted in influencing good policy that’s implemented well. This is how the Rosebank e-Micro Mobility Pilot Project was born – a small public-private partnership that goes down to the most granular level: 15 electric delivery bikes working within the Rosebank Management District precinct, sharing the same solar-powered charging kiosk that doubles as a battery swapping centre to ensure continuity.

The e-business case But why e-bikes, why e-micromobility? South Africa’s roads are built for cars and trucks.

It would be no exaggeration to proclaim that they are unsafe for e-bikes, despite the proliferation of delivery bikes in our suburbs. However, this is where we are, not where we want to be.

It should not be that one 75 kg person starts up a two-tonne internal combustion vehicle to travel 3 km to buy a litre of milk. Twowheelers take up less space, they are more environmentally friendly, more manoeuvrable, more cost-effective and ultimately quicker because of their convenience. Most importantly, they can be seen as stepping stones in mobility – they are more inclusive in bringing more people into mobility generally. Introduced sustainably, an e-micromobility ecosystem will make for friendlier streets.

Delivery bikes present a solid anchor point from which to enter the e-micromobility discussion.

Since Covid-19, e-commerce has skyrocketed and will grow by 40% through 2025. This is one of the only growing segments in the economy now, and yet there is policy silence around the use of delivery e-bikes in cities. Where should they park?

What are the rules for training drivers? What are the set standards and regulations? None of these questions can be answered, yet these e-bikes are integral to our suburban and inner-city lives.

There needs to be rigorous thinking and planning around influencing policy for the sector because we can shape its growth to deliver

convenience to other parts of the city and even the townships. The pilot project talks directly to this glaring need.

If we can build a viable and safe e-micromobility ecosystem for deliver y bikes, the next step is to add commuter and personal recreational mobility to the same ecosystem.

A project like this cannot exist without massive buy-in. The private-sector-led project already has the support of the Rosebank Management District, Transport Authority Gauteng, City of Johannesburg – represented by transport, development and planning – the JRA and the Smart Cities office.

Pilot study analysis Gauging the per formance of the pilot will generate insights into e-bike and rider per formance, deliver y metrics, carbon savings, and much more.

The concept notes will include a submission to support the Transport Authority Gauteng’s 2030 Smart Mobility strategy, a concept note on a green mobility credentials ecosystem, another around a universal standard for a swappable batter y ecosystem, and a fourth specifically aimed at precinct infrastructure and management protocols for e-micromobility.

Building a world-class African city remains the goal, and this will be achieved with a bottom-up approach that lays the foundation for scale, responsive policy and, ultimately, mass buy-in. This bottom-up approach might start small, but will grow to make ‘rands and sense’, changing the face of our cities together.

IMIESA June 2023

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TRANSPORTATION

Can a new approach to tunnelling unlock underground construction potential?

As urban populations around the world rise, governing authorities are coming under increasing pressure to accommodate new demographic shifts. By Patrick Lane-Nott*

T

he infrastructure in and around cities, including transportation links to better connect rural communities, is critical to successfully incorporating larger populations and driving socio-economic progress.

Inevitably, this demands the ongoing construction of new structures and buildings – from residential accommodation and healthcare facilities to the roads and railway lines. However, many cities and urban conurbations are already struggling to find

hyperTunnel, the British technology company innovating underground construction, presents the world’s first entirely robot-constructed underground structure, built at the company’s R&D facility in the North Hampshire Downs

the space needed to accommodate these additional building requirements. Indeed, while taller and taller buildings have become a common feature of skylines, there is only a finite amount of land that can be developed.

One means of addressing this challenge is to look downwards and build underground. As a subsegment of the construction industry, tunnelling is already big business and set to expand markedly over the course of the current decade. In 2021, globally the sector was worth US$88.6 billion (R1.61 trillion) – by 2027, it is predicted to expand by more than 50% to almost $136 billion (R2.47 trillion).

In South Africa, construction underground has been an important practice for the development of water transfer schemes and metro rail extensions, as well as enabling rapid access to mining operations to boost productivity of the sector.

Using swarm construction methods according to a digital twin of the tunnel, a fleet of hyperBot robots enters the ground via an arch of HDPE pipes. Once inside, they 3D-print the tunnel shell by deploying construction material directly into the ground

18 IMIESA June 2023

TRANSPORTATION

Rather than digging through the ground with a cylindrical boring machine or using a traditional drill-and-blast technique, the hyperTunnel method installs a network of HDPE pipes to provide access to the whole tunnel length so that a swarm of multifunction robots can 3D-print the tunnel

While the importance of underground construction projects has long been acknowledged by the South African government, there are several challenges to achieving sustainable, safe, cost-efficient and timely project outcomes in the region.

These include issues relating to productivity such as geological constraints and challenges associated with tunnelling through hard rock terrains.

A new approach to underground construction To help overcome these issues, there are some big advances in technology on the horizon that promise to make underground construction, repair and maintenance significantly faster, cheaper, safer, less disruptive and more environmentally friendly.

By removing much of the risk and pain related to large-scale underground infrastructure projects, such advances promise to further boost what is an already booming sector that is only going to become more important in the decades ahead.

For well over a century, approaches to underground construction have broadly remained the same, meaning conventional practice continues to be burdened with risk, complexity and cost, as well as a heavy carbon footprint.

However, this could be about to change.

A new method of underground construction is gaining traction – one that leverages the power of swarm robotics and in-situ construction to transform the traditional tunnel boring process.

Unlocking an array of benefits First, pilot bores are drilled and lined, and robots sent inside to inspect the geology. Core samples are taken and the geology is scanned using ground-penetrating radar (GPR). The

result is a near-perfect understanding of the entire tunnel length’s geology.

Using this data, a virtual model of the tunnel structure is developed: the digital twin. With AI and machine learning, the optimum build schedule can be designed to create a sound structure in the geology.

Once the structure profile is defined, a swarm of bots is sent into the lined bores to visit planned locations in order to drill and deploy chemistry according to the AI-generated design. Thousands of robots will be used, all controlled using swarm technology to 3D-print the tunnel in much the same way that bees build a hive or termites build a mound.

The ‘bots carve precise chambers in the geology and these voids are then filled with suitable construction material. The cast-insitu blocks interlock to create a permanent structure, block by block. The initial survey robots come back to inspect the construction, ensuring that the chemical has spread evenly and precisely matches the digital twin design. The tunnel walls are prepared for final use, leaving a smart structure that can be monitored and maintained throughout its life.

Strategic gains This method has several key advantages. For example, costs are greatly reduced throughout the process, compared to conventional tunnel boring machines and drill and blast techniques. These savings cover labour and consumables, to the project cost gain of a shorter build duration.

By using thousands of robots running in parallel, many processes can be performed

TRANSPORTATION simultaneously, working throughout the structure all at the same time. Further, multiple robots can operate in each pipe as they are able to pass each other as they shuttle back and forth. This means the construction duration is determined not by a project’s physical size but by the number of robots deployed.

Several environmental benefits can also be realised. First, less energy, water, raw and composite materials are required versus conventional tunnel boring techniques. In addition, worksites are smaller and better suited to urban environments, while the spoil from the tunnel interior is uncontaminated and therefore easier to use locally without processing. With South Africa committed to reaching net zero by 2050, sustainable

The hyperTunnel team has developed its hyperBot robots in-house at its Basingstoke, UK, headquarters, and outdoor learning environment (the hOLE) and Geolab in the North Hampshire Downs

construction techniques will no doubt have their role to play if this ambition is to be realised.

Crucially, in-situ construction using robots is safer because the structure is sound before a human enters it. In terms of project risk – another factor affecting cost – the construction design is more accurate due to the superior amount of data gathered. Geological certainty provides full knowledge of the tunnel path.

Therefore, it’s much less risky.

In-situ automated construction can also be used to extend and maintain existing underground assets with minimal disruption.

The robots simply gain access via the same network of pipes to carry out their work. This means that, in many cases, roads or railways do not have to be closed. It is also an ideal solution for when direct access from above ground is difficult, which is often the case in urban areas.

From concept to deployment into the real world At hyperTunnel, we are determined to bring hyperBots perform a wide range of tasks, including chamber cutting, spoil removal, microdeep mixing cement and deployment into the geological formation of composite construction materials such as cementitious grouts or polyurea-silicate injection resins

this new vision of construction to life. In 2022, we revealed the world’s first entirely robotconstructed underground structure at our R&D facility in the UK. This has been delivered as part of a project with Network Rail, the body responsible for maintaining the UK rail infrastructure, which is eager to explore technologies that are key to low-disruption tunnel repairs. We are now currently surveying a site for Network Rail to populate a digital twin in planning for repair works.

Meanwhile, earlier this year, hyperTunnel received funding from Global Centre of Rail Excellence (GCRE) in Wales to carry out a feasibility study into building an underpass at its site using their approach. If the project progresses successfully, hyperTunnel’s system will be tested on a real site in the form of a 10 m long pedestrian-sized tunnel built under GCRE’s test track, with the railway able to remain open throughout.

Alongside these advances, development of the fleet of hyperBots continues to gather momentum. This is being turbocharged by the backing of a grant from the European Innovation Council, with the key objective being to demonstrate swarm robot behaviour in an operational environment within the next two years.

Conclusion Underground construction and repair, be it for transportation infrastructure, access to mines or many other applications in between, will play an important role in South Africa’s onward development.

As the need to accommodate growing populations and improve productivity of major economic sectors intensifies, new methods that deliver enhanced speed, safety, sustainability and value for money will be sought after. Tunnel boring has, without doubt, delivered tremendous advances by enabling underground construction – the time has come for the next generation of construction technologies to emerge. *Director of Engineering at hyperTunnel

Swarms of hyperBots are sent into each bore to build the structural shell, deploying an additive manufacturing process, similar to 3D printing

20 IMIESA June 2023

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ROADS & BRIDGES

Taking the oil out of bitumen The South African asphalt industry is working hard to reduce its carbon footprint and improve sustainability by using waste materials to provide road surfaces that last longer.

I

n this respect, AECI Much Asphalt recently completed a successful trial using non-recyclable glass in the asphalt layer. As this concept continues to develop, another potential game-changer is being tested. This time it is Instant Bio-Bitumen – a carbon-negative alternative to conventional bitumen derived from the refining of crude oil for use as the binder in asphalt products.

Instant Bio-Bitumen combines asphaltenes extracted from naturally occurring hydrocarbon resins with a maltene component derived from waste cashew nut shells. It can be produced

Instant Bio-Bitumen asphalt sampling for testing

22 IMIESA June 2023

available internationally. “We decided to investigate Instant Bio-Bitumen for use in South Africa due to its novel recipe and recent success in Europe.”

A study at AECI Much Asphalt’s Central Laboratory in Cape Town in 2022 compared the properties of a traditional asphalt mixture manufactured with 50/70 penetration grade bitumen from a local refinery and an asphalt mixture using Instant Bio-Bitumen. According to Labuschagne, the results showed that the properties of the traditional asphalt mixture using the wet blend process were similar but generally inferior to the dry blended asphalt mixture using Instant Bio-Bitumen.

by blending the ingredients or Instant Bio-Bitumen Plant trials introducing them individually compacted asphalt briquette In February 2023, during the asphalt a plant trial was manufacturing process. conducted at AECI The bio-bitumen Much Asphalt’s dramatically reduces the Contermanskloof site SHEQ risks associated in the Western Cape with traditional bitumen but not evaluated in derived from crude oil, detail due to lower-thanreduces total CO2 emissions in asphalt production, and expected binder content. provides a convenient solution for A second trial is planned, with asphalt production in remote locations. the asphalt mixture to be donated “International bitumen supply has been to a primary school for repairs and negatively impacted by the IMO 2020 maintenance to parking areas, walkways and regulations, which limit sulfur in fuel access roads. oil for ships to 0.50% for marine “We are planning more Instant Bio-Bitumen fuels globally, as well as paving trials on higherasphaltene component the international move to volume roads in the green energy. In South Western Cape,” says Africa, the closing down Labuschagne.

“We of refineries and limited are also conducting capacity of those that more research using remain means asphalt aggregates from manufacturers must different sources and import most of their bitumen Instant Bio-Bitumen with requirements,” explains various asphaltene/maltene Herman Marais, Director: ratios. The incorporation of Plant & Technical, AECI Much Asphalt.

Instant Bio-Bitumen in warm mix “We need new solutions, and the asphalt with high ratios of reclaimed asphalt is development of alternative binders for flexible the next step in our investigations.” pavements that decrease impact on AECI Much Asphalt continues the environment is a significant to explore alternative Instant Bio-Bitumen breakthrough,” he says. sustainable recycling maltene component streams for various Winning formula other waste materials Morne Labuschagne, such as foundry sand, Technical Manager: waste shock tube Bitumen, AECI Much generated by the Asphalt, adds that explosives industry, several bio-bitumen sulfur by-products and products containing few filter cake generated to no petrochemical-derived during mineral oil recycling. materials are commercially Watch this space.

ROADS & BRIDGES

Y-shaped pylons one of Msikaba’s distinctive features The Msikaba Bridge forms par t of Sanral’s N2 Wild Coast project and is being constructed by the CME JV – a par tnership between Concor and MECSA, both 100% black-owned Grade 9CE South African construction companies.

The inverted Y-shape of the concrete pylons at the Msikaba Bridge project are strikingly elegant

The pylon lifts are accomplished using a jacking system for the formwork shutters, with eight jacks around the circumference of the spire

his is the largest cable-stayed bridge to be built in South Africa, and probably one of the most complex engineering bridge projects yet executed in Africa,” explains Laurence Savage, Concor’s project director on this contract. Spanning the Msikaba River, the deck will measure some 580 m in length, bridging the close to 200 m deep gorge below.

Each of Msikaba’s two pylon spires rests on inclined legs that meet 21 m from the start of the bifurcation, which extends a full 11 m. At 32 m, the first section of the spire – starting with a diameter of 6 m – is uninterrupted for 55.7 m and comprises 14 slipform lifts. Then begins the inclusion

of 17 anchor inserts over the next 35 m of the spire, which reaches a height of 124 m, converging to 4 m in diameter. These anchor inserts accommodate the 17 cables that run from the anchor blocks, located behind each pylon to the spire, and then down to the 580 m long bridge deck.

“To accomplish the lifts, we are using a jacking system for the formwork shutters, with eight jacks around the circumference of the spire,” Savage explains. “Each lift is 3.6 m conducted at intervals of about two weeks per lift and we are making steady progress, with quality and safety being paramount.”

Like the legs of the bridge pylon, the reinforced concrete spire – with 1 m thick

T

South Africa

Each of the two bridge pylons has 17 anchor inserts, with each insert weighing 8 to 10 tonnes

walls – is hollow to reduce weight and is formed in a tubular design that significantly improves its strength-to-weight ratio.

Intensive programmes “Indicative of the precision engineering being employed on this project is the number of activities that must take place at the same time – in a confined area,” Savage explains.

“By the time we have completed the fifth anchor insert, for instance, we will have begun the launching of the first deck segment – followed shortly by the second and third segments. While these activities are taking place, the spire and inserts will continue to be erected and cast,” Savage concludes.

ROADS & BRIDGES

N3 upgrade provides opportunity for innovation

W

ork is now well underway on the upgrading of N3 Section 2 from Dardanelles (km 26.6) to Lynnfield Park (km 30.6), with GIBB appointed by Sanral to assist with the design and construction of four bridge widenings, a new ramp bridge and V-drains, among other responsibilities. Construction commenced in January 2021 with completion scheduled by May 2025.

For the project, GIBB is employing a host of new technologies and innovations, including a specialist traffic modelling software called Aimsun, new LED street lighting, and stronger and heavier road pavement material.

Innocent Magwa, bridge design engineer, GIBB, says accommodating heavy traffic volumes, land acquisition and issues around groundwater have been some of the key challenges. In addition, during the design stage, most of the existing structures did not have as-built drawings.

“We had to employ other means like conducting structural surveys and 3D scanning to establish the sizes, spans and the amount of existing reinforcement,” Magwa explains, adding that this information helped to determine the capacity of the existing structures, as well as any strengthening required due to increased loads.

Magwa says he’s proud of his involvement in the project and its progress to date. “I especially enjoyed the design aspect, as dealing with existing bridge widenings is quite complex and requires a lot of attention to detail.”

Currently, Magwa is involved in the implementation stage and the inspection of the reinforcement on the bridge sites.

Innocent Magwa, bridge design engineer, GIBB

24 IMIESA June 2023

Eastern Cape upgrades

T

he upgrading of the R410 from the R392/R410 intersection near Komani to Cacadu (formerly Lady Frere) will provide a welcome boost to the regional economy, as well as eMalahleni Local Municipality.

The latter is a 17-ward municipality comprising the towns of Cacadu, Indwe and Dordrecht, with surrounding farms and villages.

Anticipated to start within the next two years at an estimated budget of R960 million, Sanral’s progamme will include the construction of additional paved shoulders, passing lanes and slope stabilisation at the Nonesi Pass, surfacing over the full length of the road, plus the installation of traffic lights in the Cacadu CBD. In preparation for these and other works, Sanral’s SMME pre-tender training programme will be implemented within the municipality, focusing on grade 1-4 emerging contractors.

In the meantime, Sanral has appointed Rainbow Civils to implement routine road maintenance along the R410. The scope of works includes crack sealing and patching of pavements, repairing of pavement layers, edge breaks, edge drops, gravel shoulders, slope failures and washaways. The project has a budget estimate of R55.3 million.

Running in parallel, Sanral is implementing several other road infrastructure projects within eMalahleni.

These include emergency bridge repairs along the R410, with a budget estimate of R33.5 million; maintenance of the R56 and R369, valued at R56.7 million; and special maintenance of the R56 from the N6 to Dordrecht, valued at R253 million.

Other works comprise special maintenance of the R56 from Dordrecht to Indwe, valued at R304 million, as well as the special maintenance of the R56 from Indwe to Elliot and Elliot to Maclear, valued at R485 million.

27588

From waste to resource With over 40 years’ experience in the waste management industry, collaboration with customers is how we drive the circular economy.

We implement agile and innovative waste solutions, proudly ensuring environmental peace of mind through our commitment to industry standards.

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WASTE & RECYCLING

The intricacies of landfill development

What’s behind the design?

The primary criterion for determining the dimensions of a leachate dam is to ensure its ability to accommodate a 1:50 year, 24-hour storm run-off from the operating cells within the landfill

Part 2 of 2

Landfill design and construction is a multifaceted process that requires expert knowledge to ensure environmental compliance and maximum operational life. In the following commentary, Envitech Solutions’ Kris Matulovich (KM), associate director, and Molly McLennan (MM), senior design engineer, provide technical explanations to common questions concerning engineered municipal general waste landfills.

How do you size the leachate dam?

MM The primary criterion for determining the dimensions of the leachate dam is to ensure its ability to accommodate the 1:50year, 24-hour storm run-off from the operating cells within the landfill. In order to achieve this, several factors must be taken into consideration. First, an allowance needs to be made for any existing water present in the dam, which Kris Matulovich, may vary depending on the associate director, Envitech Solutions specific operations at the site.

Additionally, the rainfall depth associated with such a storm event in the particular region must be determined.

The calculated total capacity required serves as the basis for finalising the geometry of the dam. However, the depth may be limited by the prevailing ground conditions, such as the presence of hard rock or water table level. The length and breadth of the dam are typically determined by the site conditions. In terms of cost-effectiveness, square or rectangular shapes are often preferred.

By carefully considering the Molly McLennan, factors mentioned above, the senior design engineer, dimensions of the leachate dam Envitech Solutions can be determined to ensure it

26 IMIESA June 2023

can adequately accommodate the run-off from the specified storm event. This is crucial for the proper functioning and containment of the leachate within the landfill, thereby minimising the risk of environmental contamination.

What happens to the material excavated from the landfill site?

MM During the excavation of cell bases in landfills, the excess cut material is typically stockpiled for various purposes. This material is utilised for activities such as daily cover, stability berms during lifting procedures, and capping/shaping of the landfill upon closure.

It is crucial to conduct a rigorous materials balance to assess the availability of material for these operations and to determine whether external off-site material will be required in the future.

In cases where additional material is needed, builders’ rubble and other inert waste streams can be considered as potential sources of cover material. These materials can be utilised effectively to fulfill the requirements of daily cover and other necessary purposes.

The construction of perimeter berms for the landfill cell and dam is usually carried out through a cut-to-fill process. This involves

WASTE & RECYCLING

The primary excavating the required material from one between coarser and finer materials, and as a objective of the liner system in a area and using it to fill and shape protection layer, which requires a thicker landfill is to establish a robust barrier that the berms. The fill material is geotextile. All the liner materials effectively separates the waste or waste leachate from the surrounding environment compacted appropriately comprising the barrier system to achieve the desired must undergo individual compaction level, ensuring conformance testing, as well the stability and integrity of as comprehensive testing as the landfill cell. a unified system, particularly By carefully managing in terms of shear strength and the excavation process protection efficiency. and stockpiling the excess The design engineer cut material, landfills can may not specify a specific ensure a controlled and brand of product but should efficient use of available instead define performance resources. This approach parameters in accordance facilitates the proper with project requirements functioning and long-term and Geosynthetic Research sustainability of the landfill Institute specifications. by minimising the need for external What testing of the material sourcing and optimising the liner system needs to utilisation of on-site resources.

be undertaken?

What makes up the liner system and why?

KM The primary objective of the liner system in a landfill is to establish a robust barrier that effectively separates the waste or waste leachate from the surrounding environment.

While it is acknowledged that all liners may experience some degree of leakage, it is imperative that such leakage remains minimal throughout the entire lifespan of the landfill. Achieving this goal necessitates the use of suitable materials, correct installation practices, and diligent supervision and quality control. Furthermore, continuous leakage monitoring is essential throughout the operational life of the landfill.

The key component of the liner system is the high-density polyethylene (HDPE) geomembrane.

Depending on the waste category and the type of landfill facility, clay layers may also Welding of the geomembrane liner sections should only be carried out by specially trained experts

A defective lining system threatens the overall environmental integrity of the landfill

be incorporated into the barrier system.

Permeability tests must be conducted on the available clay material to ensure that its permeability does not exceed 1 x 10-7 cm/s (as stipulated in the relevant norms and standards). If appropriate clayey material is not available, a geosynthetic clay liner (GCL) can be used, provided that testing demonstrates equivalent barrier performance. A drainage layer is required beneath the geomembrane to facilitate leakage detection. This drainage function can be fulfilled by either a layer of aggregates or a geosynthetic alternative such as a cuspated HDPE sheet drain.

Geotextiles play two vital roles in the liner system. They serve as a separation layer

KM To ensure the stability and effectiveness of the liner system in a Class B landfill for municipal solid waste (MSW), various tests are required for the individual liner components and their combined configurations. The following tests are typically anticipated: Compatibility testing If acceptable clay is not available, a GCL is used. Swell index testing is conducted using actual leachate from the landfill site. If the landfill is not established yet, the testing is carried out using common chemical components found in MSW leachate.

Protection efficiency testing The control of strain values within geomembrane liners is crucial, with a maximum limit of 3% deemed acceptable.

The primary source of strain on the geomembrane liner is attributed to the leachate

WASTE & RECYCLING

During the excavation of cell bases in landfills, the excess cut material is typically stockpiled for various purposes such as daily cover, stability berms and the capping/ shaping of the landfill upon closure

collection or leakage detection aggregates employed in the Class B facility. These aggregates present the highest risk of inducing strain on the geomembrane liner. To mitigate the strains, the installation of a protection geotextile layer between the geomembrane and aggregate layer is necessary.

To assess the effectiveness of strain reduction, protection efficiency testing is conducted by an accredited international laboratory. This testing involves subjecting the entire lining barrier system to specified loads determined by the design engineer. If the strain on the geomembrane exceeds the allowable 3%, adjustments need to be made. This can involve increasing the density of the protection geotextile and retesting. Alternatively, altering the size, uniformity and angularity of the aggregates can also impact strain levels on the geomembrane liner.

Based on our findings, the use of a uniform 37.5 mm aggregate generally necessitates a 1 000 g/m2 protection geotextile, while larger or non-uniform aggregates of 22-34 mm may require a 1 200 g/m2 geotextile. It is important to note that the cost difference between these two types of protection geotextiles can range from All the liner materials comprising the barrier system must undergo individual conformance testing, as well as comprehensive testing as a unified system, particularly in terms of shear strength and protection efficiency

HDPE liner after testing

28 IMIESA June 2023

R8.00 to R10.00 per m2. Considering the coverage area of a landfill cell, this cost variation can have a significant impact.

Therefore, the design engineer should carefully specify lining and aggregate components that not only ensure an effective barrier system but also prove to be cost-effective.

To ensure the suitability and performance of the lining configurations employed in the proposed landfill, protection efficiency testing must be conducted on all utilised configurations.

The imposed loading specified by the engineer typically aligns with the maximum height of the landfill, with the greatest loading occurring at the basal area. This loading is then multiplied by an estimated bulk density of 1.5 t/m3. A factor of safety of 1.3 is applied to the resulting confining pressure to determine the final pressure used in the testing process.

Shear box testing Shear box testing is a critical step in evaluating the interface friction between different lining elements in a landfill. It helps determine the coefficient of interface friction (COF) and cohesion of the lining combinations, which are essential parameters for slope stability, global stability and veneer stability calculations.

Interface friction refers to the resistance to sliding or movement that occurs at the interface between different materials within the landfill liner system. This friction is a crucial factor in landfill design, as it directly impacts the stability, integrity and effectiveness of the liner

Protection geotextile after testing

Aggregates used in testing

system in preventing the leakage of pollutants into the surrounding environment. When subjected to external forces like differential settlement, slope instability or internal waste pressures, the liner materials can experience shear stresses along their interfaces.

The COF quantifies the interface friction and represents the ratio of the shear stress at the interface to the normal stress acting perpendicular to the interface. It depends on factors such as the roughness, surface properties and compaction of the materials, as well as the applied normal stress.

A higher COF indicates a stronger resistance to sliding, indicating better stability and performance of the liner system.

It helps prevent separation or sliding of the liner materials, ensuring the integrity of the barrier and minimising the risk of contaminant migration.

In a Class B landfill application, it is typically designed for the COF between the geotextile and geomembrane to be lower than the COF between the geomembrane and GCL. This design approach ensures that in the event of a failure, the geomembrane liner remains intact while slippage occurs on the protection geotextile. To further enhance the COF between the geomembrane and GCL, a textured HDPE liner can be specified with the textured face placed downwards, providing additional friction.

By conducting shear box testing and considering factors such as protection efficiency and COF, the design engineer can make informed decisions regarding the selection of appropriate lining and aggregate components. This ensures the establishment of an effective and cost-efficient barrier system for the landfill.

What engineering analyses need to be undertaken?

KM To ensure the stability of the proposed landfill, slope stability analysis is conducted, and the calculations are included in the submission to the regulator. The input parameters for the analysis are based on recent laboratory test results and previous experience with similar projects. These

Foil backing to capture strain deformations

Strain distribution of geomembrane

WASTE & RECYCLING

parameters will be verified during construction to ensure the correct selection of geosynthetic materials for the liner system.

In terms of interface friction, the critical interface for a Class B landfill is identified as the smooth HDPE geomembrane/protection geotextile interface on the landfill base.

The stability analysis is performed using GEO5 2023, a slope stability program that calculates the stability of slopes and embankments with circular or polygonal slip surfaces. For polygonal or non-circular slip surfaces, the program offers methods such as Sarma, Spencer, Janbu, MorgensternPrice, Shahunyants and ITF. The Sarma and Morgenstern-Price methods are commonly utilised for this analysis.

The Sarma method, developed in 1979, falls under the category of general sliced methods of limit states. It ensures force and moment equilibrium conditions for individual blocks created by dividing the region above the potential slip surface with planes of varying inclinations.

The Morgenstern-Price method, established in 1967, is a general method of slices based on limit equilibrium. It satisfies the equilibrium of forces and moments acting on individual blocks, which are created by dividing the soil above the slip surface with vertical planes.

During the modelling process, a water table is incorporated into the system at 300 mm above the landfill base to simulate a 0.3 m head of leachate within the leachate collection aggregate layer (worst-case scenario). It is important to note that shear box testing is also conducted using saturated lining components to test worst-case scenarios.

The output of the modelling must yield a factor of safety greater than 1.3 for the landfill to be considered acceptable.

Additionally, a veneer stability analysis is performed on the cell slope liner system according to the methodology of Soong and Koerner (2005), as described in Designing with Geosynthetics, 6th Edition by Robert M Koerner. A range of input parameters, derived from laboratory testing or assumed, is used to calculate the factor of safety. The analysis typically considers the full slope length of the landfill, excluding any benches, to ensure a conservative approach and enhance confidence in the stability of the landfill.

How does one ensure that all the liners, stone aggregates and soils are placed correctly and as per the design?

MM As per the requirements set by the regulator, the design engineer is obligated to submit a construction quality assurance (CQA) plan for the proposed landfill. This plan provides detailed specifications for the lining components and outlines the principles and practices of construction quality assurance to be followed during the installation of the specified liner materials. The plan also includes information regarding the frequency of confirmatory testing throughout the lining procedures. It serves as a guideline for the lining contractor during the landfill construction process.

Additionally, the client is responsible for appointing an independent CQA officer who will oversee the lining process in accordance with the design engineer’s CQA plan and data capturing sheets. The CQA officer’s role involves documenting all destructive testing

Drainage pipe installation connecting the landfill with the leachate dam

conducted on-site, capturing photographs of the testing, and recording videos of activities such as material offloading and cell lining whenever possible.

It is important to note that while the independent CQA officer oversees the lining process, the ultimate responsibility for the landfill facility and barrier system remains with the registered design engineer.

Therefore, strict site supervision of the construction activities, including earthworks and lining, is consistently carried out

by Envitech, the designated party responsible for ensuring compliance with the design specifications and quality assurance protocols. *Part 1 was published in the March 2023 edition of IMIESA.

Transportation of geosynthetic clay liners for a landfill project IMIESA June 2023

29

Responsible for the installation of over 20 anaerobic digestors in Africa, Talbot has extensive experience in building, designing as well as operating biogas plants, and is beginning to see an increase in biogas projects.

By Kirsten Kelly

30 IMIESA June 2023

WASTE IS NO LONGER A FORGOTTEN RESOURCE

O

ur specialisation is water and wastewater.

Anaerobic digesters are one of the tools in our box.

Interestingly, when Talbot initially installed anaerobic digesters some 20 years ago, biogas was viewed as merely a by-product.

Today, more and more of our clients are utilising biogas for electricity or heat generation, as it is much more financially feasible,” says Grahame Thompson, project director, Talbot.

Biogas is dependent on the amount of organic matter in the wastewater. “Most of our builds have been for the food and beverage industry where there is a high volume of sugars in the wastewater.

There are also massive opportunities in the pulp and paper industry. But unfortunately, not all industries are suited to biogas production due to some toxic elements found

in the wastewater. Interestingly, domestic wastewater typically has low organic content and may not be the best option for biogas production, which is why aerobic processes are mostly used in municipal wastewater plants,” he adds.

Feasibility When assessing the feasibility of a potential biogas project, Talbot will look at both the economic and technical aspects. “We need to understand the drivers – it could be compliance, security of energy supply, waste management or environmental sustainability.

We then look at the volume of wastewater and the organic content and understand where the wastewater is discharged.

ABOVE LEFT Mike Smith, associate director, Talbot LEFT Grahame Thompson, project director, Talbot

WASTE & RECYCLING

There may be a limit on the amount of wastewater to be discharged or the tariffs may be expensive,” says Mike Smith, associate director, Talbot.

The chemical oxygen demand (COD) in wastewater determines the size of the digester. Biochemical oxygen demand (BOD) could be used to measure the organic content in wastewater, but COD is a faster test. The more COD in wastewater, the better the economies of scale. “Typically, a feasible biogas project in South Africa five years ago would require more than 5 000 mg/ℓ of COD. Today due to advances in technology and stricter regulations and higher tariffs around the discharge of wastewater, 2 000 mg/ℓ to 3 000 mg/ℓ of COD is feasible for a bigas project,” explains Smith.

The size of anaerobic digesters has also drastically decreased over the years and they therefore take up a much smaller footprint. They are also tightly sealed and therefore no longer release any odours. Depending on the wastewater and conditions, the conversion of waste to energy is significantly faster.

In addition to biogas, anaerobic digestion facilitates water recovery, reducing the amount of wastewater discharge and the use of potable water. “In South Africa, there is a huge interest in water reuse because our municipal systems are under strain and recovering water from industrial effluent limits the pressure applied to water and wastewater treatment facilities,” states Thompson.

Due to the high cost of anaerobic plants, there are various financing options. In some instances, Talbot can fund an anaerobic digestion plant, use the client’s wastewater and then charge for the plant’s output (water recovery/biogas).

“The client is receiving the benefits, and paying for it on a tariff basis, instead of laying out a huge amount of capital. Smaller anaerobic digesters can be rented on a three-year or longer basis,” adds Smith.

Challenges Thompson describes an anaerobic digestor as a living organism that constantly changes. Operators of biogas plants must constantly monitor the system and adapt feeding rates accordingly. It is important to remember that anaerobic digesters operate within certain temperature, pH and organic loading rate parameters. Biogas digesters can be overfed.

“It is important to know what has been fed into the system. For instance, dumping hydrocarbons or a biocide into an anaerobic digester can cause serious harm. That is why Talbot has a huge focus on the operational side of the business. The success of these types of systems is reliant on experts that monitor and control inputs and outputs of these digesters. The output of the digester largely depends on its input. Our experience in operating digesters across Africa is where we have developed a lot of our skill set.”

Anaerobic digestion holds significant promise for a country like South Africa with its energy and water problems. “This creation of energy from rich organic effluent has become a successful reality and is being applied by an increasing number of food and beverage manufacturers worldwide. These industries have started reaping the environmental and financial rewards and we look forward to more projects in the future,” he concludes.

Illegal tyres pose a pollution and road safety risk

T

he local tyre manufacturing industry estimates that the second-hand tyre market in South Africa ranges between 1.5 to 2 million units, of which 750 000 to 900 000 are illegal and pose a road safety threat.

According to Regulation 1 of the Waste Tyre Regulations, 2017 (GN 1064 of 29 September 2017), waste tyres encompass various categories, including new, used, retreaded and unroadworthy tyres unsuitable for retreading, repair or sale as part-worn tyres. Part-worn tyres refer to used tyres that can safely return to their original intended use after undergoing retreading, complying with the National Road Traffic Act (No. 93 of 1996) and its associated regulations.

However, concerns persist regarding the lack of a comprehensive tyre waste management plan in South Africa, with the draft section 29 Integrated Industry Waste Management Plan for Tyres still pending finalisation.

“Waste tyres present environmental hazards due to their large volume and slow decomposition rate, leading to visual pollution and potential health risks when they accumulate in landfills or are illegally dumped. In South Africa, waste tyres have also been misused during protests and riots,” says Lubin Ozoux, CEO of Sumitomo Rubber South Africa.

Industry initiatives “As a tyre manufacturer and member of the South African Tyre Manufacturers Conference (SATMC), we have a responsibility to ensure that the practice of selling unsafe, ill-suited and illicit second-hand tyres to unsuspecting and uninformed customers is stopped. There needs to be a solid protocol for all tyre dealers to ensure that once second-hand waste tyres are correctly mutilated and have been assigned for waste pick-up from their stores, they do not resurface in the market,” he adds.

The SATMC has been collaborating with the Tyre Importers Association of South Africa, the Tyre Equipment Parts Association and government to ensure that steps are taken to drive improvements and sustainability in both the collection and processing of tyre waste. Some pressure has been alleviated by identifying additional municipal landfill sites to serve as temporary storage facilities. Examples include one in LepelleNkumpi Municipality and two in Polokwane Municipality. However, a much broader, longer-term solution is needed.

IMIESA June 2023

31

INFRASTRUCTURE FUNDING & IMPLEMENTATION

THE BIG FOUR-OH

OF DBSA DEVELOPMENT PROGRESS

The Development Bank of Southern Africa (DBSA) turns 40 in 2023 – a year that also marks a major CEO leadership change following the appointment in April of Boitumelo Mosako, dubbed ‘the lioness’ by poet Jessica Mbangeni.

She takes over the reins from Patrick Dlamini – one of the most courageous leaders of our time.

By Zeph Nhleko

T

his is a time for reflection and celebration, as we wind back the clock over the past four decades and revisit the milestone events that have shaped our past and future. The DBSA storyline began in earnest in 1979 and can be divided into the apartheid and postapartheid periods.

APARTHEID PERIOD In his toespraak at the Carlton Centre Conference on 22 November 1979, Prime Minister PW Botha advised delegates, which included mostly leading white business personalities, that there was a Marxist danger to the order and stability of Southern African independent nations, his so-called ‘constellation of nations’. He claimed that the Marxist system implied neither freedom nor welfare for Southern African states.

As expected, this so-called freedom and welfare was to be attained without causing a large-scale transfer of productive assets

32 IMIESA June 2023

to black citizens. In fact, he assured the conference that it was to be attained by ensuring that assets remain in the possession of private interests, and specifically those who possess expertise.

Delegates were informed that the constellation of nations must work together to respond to this imaginary Marxist danger by, among others, supplementing existing multilateral structures.

One of the key interventions proposed was the establishment of a development bank for Southern Africa to provide technical expertise and finance infrastructure.

Foundation and landmark developments The DBSA was established in 1983 by its shareholders – the government of South Africa and the bantustans of Transkei, Bophuthatswana, Venda and Ciskei. It commenced operations in February 1984 and went on to provide loan and grant financial development interventions worth R40.5 billion between 1983 and 1993.

THE AUTHOR Zeph Nhleko is currently chief economist at the DBSA. Before this, he served as a deputy directorgeneral at the national Economic Development Department overseeing economic policy development and coordination, as well as social dialogue. This followed his role as a deputy director-general at the KwaZulu-Natal Department of Economic Development, Tourism and Environmental Affairs. Here, he was responsible for economic planning, sector development and business governance. He earlier spent many years as a senior economist analysing economic data and interpreting macroeconomic policy outcomes at the South African Reserve Bank.

Some of the notable projects facilitated during its first decade of existence include building the Fika Patso Dam in QwaQwa (now part of the Free State) for R21.5 million; rehabilitation of 62 km of the N2 road in Transkei (now part of the Eastern Cape) for R37 million; development of the R66 road linking Ulundi, Nongoma and Pongola in KwaZulu (now part of KwaZulu-Natal) for R39 million; building the DBSA headquarters in Midrand for

INFRASTRUCTURE FUNDING & IMPLEMENTATION R26 million; building the Isithebe, Madadeni and Ezakheni industrial parks in KwaZulu for R64 million; building Umtata College of Education for R35 million in Transkei and the Ndebele College of Education in KwaNdebele (now part of Mpumalanga) for R28 million; facilitating the Alexandra Township urban renewal programme for R54 million; and initiating the Lesotho Highlands Water Project for R72 million.

The DBSA also played a significant role in reshaping policy prior to the democratic dispensation in the areas of poverty, regional development, land reform, education, urban-rural interface, urban development and housing.

POST-APARTHEID PERIOD Not shutting down the DBSA at the dawn of democracy was one of the good decisions made by the government of national unity. A transformation committee was established in December 1994 to advise the Minister of Finance on the focus, structure and functions of a transformed DBSA. The committee reviewed the development finance system in South Africa and recommended that the DBSA (or the Infrastructure Development Bank, as they suggested at the time) should narrow its focus of operations to infrastructure development.

More specifically, it was recommended that the bank should be reconstituted as a South African government subsidiary and its primary

purpose should be to promote economic growth, development, human resource development and institutional capacity building through sustainable development projects and programmes centred around the provision of infrastructure.

Since then, the DBSA has grown its annual level of loan disbursements from R717 million in 1994 to R12.9 billion in 2022. During the same period, interest income increased from R547 million to R8.9 billion; the loan book from R4.8 billion to R90 billion; shareholder equity from R4.5 billion to R42.9 billion; net earnings from R255 million to R3.6 billion; and total assets from R6 billion to R100 billion.

Today, the DBSA is working on an infrastructure project pipeline worth more than R155 billion across its various divisions.

A-category rating and unqualified audits While the bank’s credit rating is capped at that of the sovereign, the Association of African Development Finance Institutions Peer Review mechanism – which performs ratings among African DFIs – has rated the DBSA at the prestigious A-category for the past five years. Similarly, auditors have granted the DBSA unqualified annual audit opinions since its inception.

This performance has allowed the bank to increase its non-lending development contributions and increase its development impact. Annual grant support increased from R6.8 million in 1994 to R72 million in 2002.

And during the past decade alone, the bank – through its infrastructure build process – has built and refurbished 726 schools, completed 404 health facilities, and 456 social houses. The bank has also contributed to this remarkable development impact by facilitating the creation of more than 37 000 jobs in 2022 – compared with only

300 jobs in 1994 – and supported small blackowned businesses to the tune of R3.2 billion, compared with R10.5 million in 1994.

Peaks and troughs It is acknowledged that the overall national economic performance from 1994 to 2022 falls short of citizens’ expectations, with national GDP averaging 2.4%, unemployment 25%, poverty 51% and inequality 68%.

However, many South African public and private corporates have made contributions to ensure that we stay afloat over these past 29 years. The DBSA is one of them. It is therefore an unfounded myth to say all stateowned enterprises (SOEs) are dysfunctional.

The DBSA is among those SOEs that remain resilient and operate in accordance with all relevant prescripts.

Staying true to the mandate The mainstay that has kept the DBSA resilient and ensured impressive performance since 1994 is guided by four critical factors: 1. The bank constantly strives to adhere to its corporate values of high performance, integrity, innovation, service orientation and shared vision.

2.

The bank adheres to strong governance that involves staff, the board and the shareholder.

3. The bank continuously and carefully plans leadership changes to ensure leadership stability at executive and board levels.

(The DBSA has, for example, had only seven permanent CEOs in 40 years; the three acting CEOs only spent 19 months during this time.)

4. The bank always shows appreciation to its staff and offers a sound employee value proposition in return.

Looking back, the DBSA can certainly be proud of its achievements, and going forward there’s a challenging and exciting road ahead.

In fact, the DBSA intends to multiply its current performance manyfold over the next 40 years!

IMIESA June 2023

33

WATER & WASTEWATER

Tackling cholera at the source Cholera used to be a killer of epidemic proportions. In 1817, a cholera outbreak in India continued for almost a decade, killing hundreds of thousands of people. In the mid-1800s, over 15 000 people died from the disease in Saudi Arabia, and a massive outbreak in Russia during the same period would eventually claim over a million lives.

By Chetan Mistry

E

ven though cholera was partially identified more than 2 000 years ago, it began thriving in the modern era.

Dense population levels and inadequate sanitation create colossal breeding grounds for the disease, which sees highly contagious bacteria infect the small intestine with toxins.

Things started to change in the 20th century, as municipal wastewater facilities and improved sewage systems made piped clean water a reality for most people. Today, we continue to bring that clean water to everyone because it helps eliminate dangerous diseases and improves people’s lives.

So, it is saddening to see that cholera has reared its head again in South Africa and families are experiencing the traumatic

and painful loss of loved ones. This is a critical concern, and while it is crucial to hold authorities accountable for this dramatic step back in modern hygiene, that won’t directly help those exposed to this disease.

So, how can South Africa reverse the cholera outbreak and prevent it from re-emerging? The answers lie within our wastewater treatment sites.

Challenges and solutions South Africa’s wastewater sites are in trouble. According to a 2022 report from the Department of Water and Sanitation, 105 out of 115 local wastewater treatment systems (over 80%) are in a critical state. These sites often discharge raw or partially untreated sewage into our river systems, exposing the most vulnerable and impoverished to polluted water.

Banishing this disease back to the previous century will take time and effort. But there are interventions at wastewater sites that can change the picture quickly. We can generally break them down into the following key areas: Old and ageing infrastructure: Old and

dilapidated assets such as pumps and pipes can severely limit a site’s capacity, not to mention proper maintenance.

Breakdowns lead to less capacity, creating a vicious cycle. Such legacy equipment can be revitalised with modern integrations, such as internet of things sensors or modernised with new age solutions/ products geared for optimisation, as well as greater monitoring and control. Plus, there are ad-hoc high-tech assessment solutions, such as sonic leak detection balls, that identify problems long before they emerge.

Decentralised treatment: Effluent is a key component for the spread of cholera, therefore collecting and treating it quickly and efficiently will minimise a potential epidemic. Small package treatment plants can be used closer to the source of effluent to prevent further spreading. Furthermore, clean water can be treated with UV or ozone, or a combination of both – e.g. tankers equipped with UV units can disinfect and therefore provide safe drinking water.

Disinfection at the point of consumption will minimise further contaminations. And the same principle can be applied to other water sources such as rivers.

Complex management systems: water

and wastewater treatment systems are complex and have many variables, making manual management very technical and challenging. Here, water data systems simplify management through historical data for trending, and current data for real-time, AI-enhanced analysis that delivers network optimisation, scenario planning and better decision-making. These

Chetan Mistry, strategy and marketing manager, Xylem Africa

34 IMIESA June 2023

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WATER & WASTEWATER systems work on devices such as phones or tablets and can send immediate alerts to authorities.

Load-shedding: power is crucial to wastewater treatment sites. A loss of power causes devastating knock-on effects, including sewage spillages. Sites can invest in backup power solutions and reduce their energy reliance with more efficient equipment. For example, variable-frequency drive pumps and new-generation aeration blowers reliably deliver energy savings of 60% and higher.

Depleted budgets: money is tight, and improving water systems can be expensive. Yet there are some costeffective interventions. Municipalities can increase revenue through improved metering systems, coupled with automated meter readings and proactive condition assessments for detecting leaks and ensuring infrastructure integrity to reduce and prevent non-revenue water. In adopting a digital approach, municipalities can analyse historical data to discover efficiencies and avoid expensive repairs through preventative maintenance.

Lack of skills: treating water is technical,

and smaller sites, in particular, might struggle for access to enough experts.

Water solutions partners can help provide those skills directly and pass knowledge to the site employees.

Leading water solutions providers such as Xylem also fund university students’ education, ensuring the next generation is ready to step up.

Community knowledge: wastewater treatment sites are the primary defence against waterborne diseases.

But communities can do a lot as well. On the macro scale, they can look after water areas such as rivers and wetlands, and help reduce pollution. On the micro level, they can make direct interventions such as washing hands, boiling water and using chlorine tablets. It is imperative to work with local communities and share knowledge.

In conclusion Cholera outbreaks are a symptom of failing wastewater treatment facilities, and the

long-term solution is to turn these sites around. We can do this by combining modern innovations in water systems with experience and established infrastructure. South Africans deserve clean and safe water – let’s work together to deliver this fundamental right.

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WATER & WASTEWATER

Inside Johannesburg Water’s Commando System Ageing infrastructure, prolonged load-shedding, vandalism and a growing population have put Johannesburg Water’s Commando System under serious pressure. It is prone to water shor tages, along with low water pressure, especially in highlying areas of the supply zone.

N

amed from where the Rand Water supply meter is located (Commando Road, Industria), the Commando System receives water from the Rand Water Eikenhof Pump Station and supplies water to: • three hospitals (Rahima Moosa Mother and Child Hospital, Helen Joseph Hospital and Garden City Hospital)

THE JOHANNESBURG WATER COMMANDO SYSTEM COMPRISES: • The Brixton, Hursthill and Crosby complexes • Four reser voirs: -C rosby Reser voir (46 Mℓ capacity) - Hursthill Reser voir 1 (22.7 Mℓ capacity) - Hursthill Reser voir 2 (22.7 Mℓ capacity) - Brixton Reser voir (22.7 Mℓ capacity) • Brixton Water Tower (1.1 Mℓ capacity) • Two pump stations: - Crosby Pump Station - Brixton Pump Station

36 IMIESA June 2023

• two universities (University of Johannesburg and University of Witwatersrand) • parts of Region B (Northcliff, Melville, Auckland Park, Bordeux and Br yanston extensions) • Region F (Johannesburg CBD, City Deep, Robertsham, Linmeyer, Fordsburg, Kibler Park and Mulbarton).

The reser voirs are interdependent, meaning they rely on each other for water.

Therefore, an issue of supply to one will have a ripple effect, causing the others to also lose supply. The Crosby Reser voir feeds the gravity zone (the area that is on the outlet of the reser voir such as Langlaagte and Industria) and pumps into the Brixton Reser voir. The Brixton Reser voir has its own pump station and feeds the gravity zone (Brixton, Mayfair, Hursthill, Jan Hofmeyer) and high-lying areas (Melville, Auckland Park) through the tower.

Gugulethu Quma, electromechanical engineer: Operational Networks, Johannesburg Water

Brixton’s pump station pumps water from the Brixton Reser voir to the tower. Once water reaches a particular level in the tower, the pump will stop.

The entire Commando System requires a minimum water flow rate of 2 500 litres per second from bulk supplier Rand Water to supply all four reser voirs and sustain the network. However, the water flow will need to increase to ensure that water supply is greater than water demand.

“If reser voirs are at 80% capacity, Johannesburg Water is confident that it can continue to supply water to residents, even if a challenge arises. But due to various issues, it is a luxur y to have full reser voirs. When reser voirs are 20% and below, the system will experience low water pressure and the high-lying areas may not receive any water,” says Gugulethu Quma, electromechanical engineer: Operational Networks, Johannesburg Water.

WATER & WASTEWATER The Crosby Pump Station: the inlet pipes are blue, the pipes transporting water to the Brixton Reservoir are orange

The Crosby Pump Station has three pumpsets, where two are operational at all times

He adds that while parts of the Commando System can lose capacity in a matter of hours, it can sometimes take days or even weeks to replenish them. This is because Johannesburg Water must continuously supply water while trying to build reserves at the same time. “There is also the additional complexity of removing air from the pipelines and dealing with burst pipes due to pressure changes in the system.”

Challenges “Most of this infrastructure is ageing and was built in the 1940s. Furthermore, theft and vandalism at all three of the complexes are a major issue. While we have security

on the sites and armed patrols at night, vandalism and theft still regularly occur.

This affects water supply and can be timeconsuming to rectify. When thieves steal infrastructure such as valves and cables, it takes time to procure replacements while residents are left without water. Importantly, budget for infrastructure maintenance and upgrades has to be redirected to security measures,” says Quma.

Power outages are another major challenge that impacts water supply. This entails, first, load-shedding. While the Commando System is exempt from the lower levels, owing to the critical nature of the system, it is subject to higher stages of

load-shedding because of the strain on the grid. The same applies to Rand Water, and the water board can sometimes only supply a portion of the agreed-upon water to Johannesburg Water. This places pressure on the system.

Furthermore, there have also been long periods of power outages at the Commando System due to incidents of cable theft and vandalism to City Power’s infrastructure.

Unfortunately, a backup generator cannot be placed at pump stations because of security issues. “These have become high targets for crime syndicates. It is a safer option to remove the generators to protect the lives of those that are protecting our

The Johannesburg Water inlet chamber at the Hursthill Complex where water is supplied from Rand Water and sent to the Hursthill 1 and Hursthill 2 reservoirs

The Crosby Pump Station used to place a generator outside, but it attracted criminal syndicates and was removed. Therefore, if there are high levels of load-shedding, water cannot be pumped to Brixton

The Brixton Water Tower has a 1.5 Mℓ capacity

WATER & WASTEWATER

The Brixton complex suffers from vandalism and theft; Johannesburg Water has done all it can to secure the area Lepelle Northern Water is currently providing bulk water in 42% of its mandated 80 000 km2, which is equivalent to about 56% of Limpopo

infrastructure. Putting in a generator is a security risk on its own,” adds Quma.

Renewable energy can only be used to power auxiliar y and security systems, as pumps are too energyintensive. A stable, consistent supply of power is needed to run the pumps.

Fixing the struggling Commando System According to Quma, the Commando System needs additional storage capacity. “However, it is important to maximise the utilisation of all the reser voirs, particularly the Crosby Reser voir that has a 46 Mℓ capacity.”

A project is under way to add storage capacity to the Brixton complex. This is because the Brixton system is over worked and demand is often greater than supply. A second reser voir and water tower that is slightly bigger than the Brixton Reser voir will be built and located fairly close to the complex. It will be housed at a primar y school, and will ser ve as a multipurpose facility.

The reser voir will be built underground, and the top will be covered and repurposed as a playing area for the children.

“This will supplement the supply from the Brixton complex,” explains Quma.

A reconfiguration will be done to allow the Hursthill reser voirs to supply the Brixton Reser voir should the Crosby Reser voir have trouble.

The Crosby Pump Station will be upgraded in the next two years, while there are also current plans to further secure the Brixton, Hursthill and Crosby complexes.

Johannesburg Water recently completed linking Hursthill Reser voir 1 to the Northcliff Reser voir. This was done so that so that the Northcliff Reser voir – which is stable and has enough bulk supply – can boost this struggling Hursthill reser voir.

All reservoirs within the Commando System are underground

38 IMIESA June 2023

Radio monitoring aids in optimising water delivery

R

emote monitoring specialist Omniflex has completed a system revamp of legacy radio monitoring equipment for Lepelle Nor thern Water, used to monitor reser voirs and control remote pumps across the region. The new system comprises the latestgeneration, licence-free Teleterm remote terminal units.

These compact, fully radio-integrated units have universal inputs and outputs ser vicing analogue and digital signals from 12 up to hundreds of I/O. Flexible communications por ts allow direct connection to field devices such as water meters or variable-speed drives using Modbus. A working power range of 9-30 VDC makes them the ideal product for batter y-backed applications, enabling status repor ting of mains power to the site and reser voir levels even during power outages.

“We took advantage of a high site, a secure area that sits atop an old mine dump, as the main repeater station,” explains Ian Loudon, international sales manager at Omniflex. “It was the line of sight from this structure that enabled us to transmit at 868 MHz, a licence-free frequency in South Africa, enabling us to reach all the intended targets and provide unrestricted options to add any new sites as and when required using the Teleterm range of products.”

Adds Loudon: “Radio monitoring systems of this sor t have applications across the utilities industries that have ser vice deliver y commitments to consumers. Just as equipment failure in drinking water supply chains must be planned for and mitigated, power supply networks must also be monitored to allow swift action should a substation trip, and residential and industrial areas lose electricity.”

WATER & WASTEWATER

10 WAYS

TO SAVE WATER South Africa’s water resources are under tremendous pressure from a growing population, ongoing development, pollution, wetland destruction, alien invasive plants and the effects of global warming. Here are some simple ways to save water through behavioural changes.

1

Calculate your current water use

Rand Water has developed a calculator to help individuals understand their water consumption. The calculator poses a set of questions, such as how many times a day does a person wash their hands, flush the toilet and whether they have a swimming pool.

Visit the Water Wise website to find out more.

2

Draw up a plan

A Water Wise report generated from this data will show where most of the water is used. If it’s in the shower, reduce showering time. Plan on how much water can be saved. The Water Wise website has a lot of great information on saving water and reducing consumption.

3

meter is a great way of detecting if there are water leaks.

4

Make small stickers or posters

5

Watering the garden

Remember that some habits are hard to change. Make interesting posters to display around as a reminder. This is a fun activity one can do with children.

Time of day is very important when it comes to watering a garden. The earlier, the better. Try to water the garden in the morning before 07h00 or in the afternoon after 18h00. Only water when plants show signs of needing water.

Read water meters

Learn how to read a water meter to see how much water is consumed daily, weekly and monthly. More importantly, a water

6

Use greywater

7

Install a rain gauge

rainy seasons. There is no need to water a garden if there has been enough rainfall.

8

Harvest rainwater

9

Hydrozone

This can be as simple as putting a bucket outside when it rains, or installing a rain tank and directing water from the gutters into the tank. This method can also reduce the water bill.

Grouping plants according to their watering needs saves water and money.

Divide the garden into high, medium, low and very low water zones. Then water accordingly.

10

Mulch

Mulching a garden saves water, protects plant roots and prevents weeds.

Mulch helps with retaining soil moisture, making it easy to maintain a garden and reduce the amount of water needed.

The amount of water available for use remains the same, and despite plans to increase storage capacity through the building of new dams or water transfer schemes, predictions are that the demand for water will outstrip supply by 2025. Be Water Wise.

Reusing greywater in the garden is another great way of saving water. Make sure that the greywater is suitable for the types of plants you have in the garden. Visit the Water Wise website for more information.

This is a simple way of measuring how much water is needed for a garden during

FOR MORE INFORMATION ON HOW TO BECOME WATER WISE, VISIT:

facebook.com/WaterWiseRSA

www.randwater.co.za

www.waterwise.co.za/site/home.html

twitter.com/water_wise

IMIESA June 2023

39

RENEWABLE ENERGY & ELECTRIFICATION

UCT GOES THE RENEWABLES ROUTE TO LOWER ENERGY COSTS The University of Cape Town (UCT) is phasing in rooftop solar photovoltaic (PV) systems across 30 of its campus buildings as a power saving solution. Alastair Currie speaks to Omaira Jajbhay, graduate engineer: Power and Energy, SMEC South Africa, about the firm’s innovative design approach in developing optimal electrical engineering building ser vices for the client.

U

CT was established in 1829 as the South African College and was granted full university status in 1918. This makes it the oldest university in South Africa, and the longest existing institution of its kind in sub-Saharan Africa, ranking 226th globally according to the Quacquarelli Symonds (QS) World University Rankings 2022. Put another way, this means that UCT is in the top 18% of all universities worldwide, underscoring its vital role in championing research and tertiar y education in Africa.

However, sustaining this focus requires dedicated energy, which has become an increasingly scarce commodity in South

A panoramic view of UCT’s main campus

Africa given the ongoing load-shedding experienced across the countr y as national utility, Eskom, implements a daily round of rolling power cuts to protect a constrained grid. In addition to being a major impediment to society in general, rising Eskom tariffs have also made electricity increasingly costly, motivating the need for alternatives like renewable energy.

In UCT’s case, the decision was made to go the solar PV rooftop route as a complementar y power source for the existing standby diesel

Omaira Jajbhay, graduate engineer: Power and Energy, SMEC South Africa

40 IMIESA June 2023

generator (genset) backup systems, with the solution designed and project managed

by SMEC. As Jajbhay explains, it’s a model intended to achieve operational and financial efficiencies.

Buildings earmarked for solar PV The 30 buildings selected on UCT’s main and allied campuses will now be progressively equipped with rooftop systems.

Those selected in the first

RENEWABLE ENERGY & ELECTRIFICATION

phase comprise the Baxter Theatre, UCT Graduate School of Business, the Molecular and Cell Biology building, and UCT’s Meulenhof administration facility.

Their combined PV outputs will equate to around 500 kWp; in all instances, the PV panels installed will be Tier 1, which is the highest industr y standard globally.

“What makes this solar project distinctive is that it’s a grid-tied system.

In other words, batter y storage is intentionally not part of the design. When load-shedding occurs, the solar PV system will automatically sync with the gensets and run in parallel, thereby contributing towards lower diesel consumption costs,” says Jajbhay, who is the lead design engineer and project manager responsible for all implementation phases.

Baxter Theatre, the largest of the four buildings, will be installed with a 151 kWp system. This will also be the first installation to be fully commissioned before successively moving on to the other three buildings in Phase 1, with the overall project costs valued at around R8 million for scheduled completion by the end of 2023.

“For these projects, we use an ideal DC (power of the modules) to AC (power of the inverter) ratio of 1.2, which provides an excellent yield. For the Baxter Theatre, for example, the inverter will be 125 kW to cater for the 151 kWp solar PV output,” says Jajbhay.

The groundwork Following an in-depth analysis of UCT’s

peak and off-peak demand, the first step in the design process was to carr y out a detailed structural inspection on each of the four buildings’ roofs.

“We needed to per form individual weight calculations to determine their capability to handle a solar installation. We also needed to factor in Cape Town’s seasonally high wind conditions. Plus, in most cases, there were existing HVAC installations, water tanks and transformer installations to consider, so each of the four buildings presented a different set of scenarios.

Provision has also been made for walking space for routine maintenance,” Jajbhay continues.

Buildings with a flat concrete roof like the Molecular and Cell Biology building can support larger 660 W panels fixed to a ballast mounting system to counter wind loads, with the roof also being able to withstand the weight of the mounting structure. In contrast, the Meulenhof building will have a flush-mount installation since the tiled roof itself has a 30-degree tilt, while the Graduate School of Business will feature a standard fixed-tilt mounting system supporting 660 W panels.

Additionally, the Baxter Theatre will have a flush-mount installation consisting of 420 W panels due to the roof’s original tilt, orientation configuration and the building’s heritage grading. The panels are smaller because the roof is made of corrugated sheet, and its structural integrity must be considered.

“The benchmark for rooftop solar PV in South Africa is to position the panels in

When load-shedding occurs, the solar PV system will automatically sync with the gensets and run in parallel, thereby contributing towards lower diesel consumption costs.”

a north-facing orientation and to set them at a tilt of 0 to 30 degrees. However, the greater the tilt, the greater the weight and wind impacts, so that always needs to be considered. For the concrete roof system and the Graduate School of Business, we’ve managed to get this down to a 10-degree tilt to achieve the best result given the wind factor,” Jajbhay explains.

Grid connectivity The solar system will be connected to the City of Cape Town’s grid, following its voltage frequency at the point of connection. When a power outage occurs, and the city’s grid is shut off, UCT’s generators will kick in as normal, and the solar system will then automatically follow the frequency of the generators via a genset controller.

From a monitoring perspective, all solar PV installations with an output greater than 100 kWp require a Scada system in terms of City of Cape Town regulations. However, for systems lower than this, per formance can still be monitored in real time via the OEM app supplied with the inverters. This will aid SMEC in refining UCT’s evolving solar PV footprint. And if, at a latter stage, load-shedding becomes a thing of the past, then SMEC’s design caters for the possibility of selling, or wheeling surplus power back to the city.

“For any solar PV installation, a professional design methodology is essential. It’s definitely not an add-on system. Each project needs a dedicated approach that meets the end-user requirements. For UCT, it’s a tailormade solution that reduces their carbon footprint, cuts their energy bill, and keeps the university operational and connected with its approximately 30 000 students,” Jajbhay concludes.

IMIESA June 2023

41

PLANNING & BUILDING SA’S METROS | GEOMATICS

Defining the natural ground level is the foundation for approved development The importance of determining the natural or altered ground level before any construction commences can never be neglected in pre- and post-construction activities at a municipal level. First and foremost, this legal verification requires the sign-off of a professionally registered land surveyor, and the implications of not adhering to this stipulation have major legal implications.

By Hans Kaderli* and Altus Strydom**

T

here are a range of complexities that must be considered. These include the imposition of natural ground height restrictions, stormwater management and issues with lateral support of buildings or structures.

Land surveyors are often requested to conduct surveys where natural ground height is crucial. Examples include setting

out building positions and floor heights from approved building plans. At times, it is then discovered that the contour detail on the plan and the actual ground contours totally disagree.

Other key criteria include: • confirmation of the vertical building line of the roof height or floor level, as defined by the relevant local authority

• confirming the horizontal building line of the building, as defined by the relevant local authority • resolving disputes with natural flow of water over or across property • resolving disputes with cut and fill during construction • addressing disputes where garden walls are used as retaining walls • responding to disputes where there are discrepancies between contours on plans that don’t conform with the status of the terrain.

In the case of sectional title surveys, land surveyors must issue a certificate prior to lodgement with the surveyor general noting that no building encroaches building lines or height restrictions.

This needs to be determined by actual survey and research. Equally important for all buildings is the confirmation of flood lines to counter disputes that might arise during severe storms, the 2022 Kwazulu-Natal floods being a case in point.

But what is the true definition of natural ground level?

In general terms and definitions, most of the municipal zoning schemes refer to natural ground level as:

42 IMIESA June 2023

PLANNING & BUILDING SA’S METROS | GEOMATICS

• the level of the land in its unmodified state, or • when altered with the municipality’s approval, for the purpose of development, the altered ground level, subject to certain conditions.

Once the basic infrastructure is installed in any land development, where the natural ground level is altered – and therefore not in the original state – it cannot be referred to as ‘natural ground level’ unless approved by a local authority or similar institution.

Determination of natural or altered ground level In this respect, it must be stressed that the determination of natural or altered ground level is the function of a spatial and mapping specialist (i.e. a professional registered with SAGC) and not a planning function.

This is a specialised field of survey where the density of ground survey points determines the accuracy of the contours. There are technical formulas that need to be applied to derive a certain accuracy of contours for design purposes.

The following are practical examples: If ground survey points are spaced at 20 m intervals, it is not possible to accurately determine 0.5 m contours on sloping terrain.

The bigger the slope, the more closely the survey points need to be spaced.

If a dispute arises on a building site where 0.1 m to 0.3 m height differences are in dispute, then the spacing of ground survey points during the initial survey should have been 1.5 m to 2.5 m apart.

When confronted in court, only a person that is registered as a professional land surveyor or professional surveyor and registered in terms of the Geomatics Profession Act (No. 19 of 2013) will be able to survey and determine natural ground level.

Survey specification for a contour of natural height survey Engineers, planners, architects or anybody that needs accurate heights or contours must be aware that a technical specification must be included in their request for proposal.

The person specifying accuracy must take the following into consideration: • the purpose of the survey and design accuracy required • accuracy of the surveyed point – to achieve the desired plan accuracy, the slope of the terrain plays an enormous role in the density of points surveyed • design tolerance of equipment used.

Internationally accepted standards are between

5 cm and 10 cm for contour surveys of building sites. Most conventional ground survey instruments (total stations) can achieve this accuracy but when GPS, drone and aerial survey equipment are used, the design tolerance must be specified as well.

Plan accuracy The next question then is what should the accuracy of contour lines be on a plan?

Internationally accepted standards vary, but in general indicate that the vertical accuracy standard requires that the elevation of 90% of all points tested must be correct within half of the contour interval.

Here’s an example to illustrate the point.

With a contour interval of 1 m, the map must correctly show 90% of all points tested to be within 0.5 m of the actual elevation. The effect of this is that if an engineer wants to design to 10 cm accuracy, 90% of points surveyed must be within an accuracy of 5 cm to accurately depict the situation on the ground.

Ways to determine natural or altered ground There are various ways of determining natural or altered ground, which include the following: • actual ground survey methods and creating digital terrain models • aerial survey methods • sourcing old contour plans and referencing them to the current state of the land • data filed with the Office of the Chief Directorate: National Geo-spatial Information.

The methodology used is dependent on the accuracy required. For example, you cannot determine 1 m contours by aerial survey if the terrain is not clear of tall grass, trees and shrubs.

Relevant court cases The importance of the correct determination of natural or altered ground level is addressed in various court case outcomes. For reference, readers can access a range of court cases online referring to natural ground level disputes.

Typical legal challenges refer to stormwater issues. In general terms and definitions, most of the Municipal Zoning Schemes refer to stormwater as water resulting from natural processes. Within this context, a judgment regarding stormwater addressed in the

South Gauteng High Court – Pappalardo vs Hau (Case No. 63/08) – is worth noting.

Effectively, it says that you can only pass on water to an adjoining property when you can prove it’s ‘natural water’. Hence the verification of the original natural ground level becomes important to that proof. In absence of proof, the water cannot be passed on. This judgment clearly expresses the importance of having the natural or altered ground level recorded before any construction commences.

Height restrictions There were several cases where natural ground height was decided and ruled on, and all of them confirm the definition of natural or altered ground level as discussed above. Legal cases to note are Du Toit vs Knysna Municipality and others (2954/2014), and Buchanan vs Hope and other (654/2010).

Imposition of height restrictions on municipal planning level Without the presence of the natural or altered ground level, and permanent reference marks for the datum of such ground level, the imposition of any height restriction (by any method) becomes a difficult, if somewhat impossible, task in any developed area.

Methods of defining a height restriction are vast. Possibilities include: A 3D surface parallel to and above the existing natural or altered ground level.

After consultation with a sample group of architects/draftspersons, it is apparent that this method is an acceptable approach.

However, not all professionals drafting

PLANNING & BUILDING SA’S METROS | GEOMATICS

F or municipalities, it is good land administration practice to record natural ground level (or in some cases altered ground level) in building control.

Municipalities can assess all development and building plans and approve these prior to construction. Otherwise, the risk for the municipality is that they could issue a clearance/occupation certificate after construction and the owners might then start holding the municipality liable.

In a nutshell, the municipal occupation certificate says what you have built is according to plan.

Solutions

building plans have software that can produce such a surface. It must be stressed that the correct input data is of utmost importance with this method.

Determination by a plane that is parallel to and above a certain height to the plane that is defined by connecting the highest cadastral beacon to the lowest cadastral beacon. This method is simple and can be calculated by most software packages.

Determination of the centroid of a property and imposing a height restriction in a plane above that point. This method becomes challenging when a very irregular figure is dealt with.

A certain plane on a height from street level to a distance away from the street and then following the natural ground level of the property.

Different height restrictions can also be given to properties in close proximity by simply classing them in the percentage of slope of the land.

The purpose of this article is not to question the method of calculating the height imposition, but to stress the importance of recording the correct data to impose same.

Which Acts regulate the production of plans for municipal construction purposes?

Each municipality has its own specifications and management structures and should be scrutinised by professionals prior to construction. Aspects that need to be noted are the following: Internal municipal documentation: The town planning scheme or land use management regulation in operation at the time of

44 IMIESA June 2023

application specifies height and building line restrictions.

Building plan submission: Building plans

are controlled by the National Building Regulations and Building Standards Act (No. 103 of 1977), but each municipality has its own interpretation.

Here, relevant clauses to note include: Administration Part A6 – Site Plans (c): the direction of true north, and if required by the local authority, the natural ground contours at suitable vertical intervals or spot levels at each corner of such site.

Administration Part A7 – Layout Drawing (j): where required by the local authority, the levels of the floors relative to one another and to: (i) the existing ground level surface (ii) the proposed finished ground surface.

Risk management proposal From the above commentary, it should be clear that the involvement of a professional land surveyor in all phases of pre- and post-construction are essentially for legal compliance. This includes the necessity of a comprehensive risk management survey.

The following observations support this: When looking at the relevant court cases, it is clear that in many cases the municipality was involved in the case, and this is a risk that they should not take.

All stakeholders must comply with the stipulations of the National Building Regulations mentioned above.

Unrecorded accurate natural ground level or altered ground level scenarios create risks for the public, engineers, local and central government.

Certain municipalities already request the submission of a registered professional land surveyor’s certificate (i.e. contour plan of existing ground level, being natural or altered) to determine the natural ground level before any construction activities may commence.

It is then the duty of the land surveyor to determine the various positions of the roof ridges and plot them on the predetermined natural or altered ground level to ensure that the building will – after construction – complies with the height restrictions.

Conclusion The role of a professional surveyor registered in terms of the Geomatics Profession Act is crucial in the determination of natural ground level.

To avoid future legal action and/or claims, the following is proposed: Affected parties subject the submission of any new building plans to the compulsory addition of the natural or altered ground level before construction.

The addition of final floor or roof levels must refer to permanent height reference data before an occupation certificate is issued.

All submissions must be accompanied by a certificate signed by a registered professional land surveyor that the building to be erected and depicted on the building plan complies with all horizontal and vertical height restrictions. *Professional land surveyor at TMK Land Surveyors and member of the South African Geomatics Institute **Professional land surveyor and board member of the South African Geomatics Institute

PLANNING & BUILDING SA’S METROS

CAPACITY BUILDING AND ENGAGEMENT CRUCIAL FOR INFRASTRUCTURE RENEWAL The need for greater collaboration was the underlining message as stakeholders met and discussed the role of the private and public sectors in infrastructure development and economic growth for KwaZulu-Natal at the CESA Presidential Function, held in Umhlanga, on 8 June.

D

uring his presidential address, Olu Soluade, president of CESA, stated that clear guidelines, transparent processes and supportive policies would encourage private investment and foster a conductive environment, especially in KZN following the devastating flood damage experienced in 2022.

Naomi Naidoo, board and KZN branch member, CESA, concurred, indicating that it was key to show resilience in this time of great need to rebuild the province. She asked a pertinent question to all stakeholders: “Are we rebuilding our infrastructure fast enough to enable the lives of citizens to return to some level of normality in order to create employment opportunities and to drive economic growth in KZN?”

L-R: Chris Campbell, CEO, CESA; Naomi Naidoo, board and KZN branch member, CESA; Mabuyi Mhlanga, programme manager: N2, Sanral; Olu Soluade, president, CESA; and Lavern Moodley, chief civil engineer, eThekwini Transport Authority

quality infrastructure, failing infrastructure and the absence of infrastructure in this environment are serious threats to the quality of lives of the people.”

“Moving out of the province, we are also all aware of the cholera outbreak in Hammanskraal in Gauteng. So, if we fail to address the poor, dilapidated water and sanitation infrastructure, we take the risk of inviting diseases into our homes and placing the health and livelihoods of South Africans at risk.”

Soluade added that the current water and energy challenges are stretching our resilience to the maximum, in addition to challenges related to transport systems, healthcare systems and educational institutions, to name a few.

Raising competency levels Investing in maintenance Naidoo also stressed the importance of investing in maintenance in the province and highlighted that the floods in KZN really exposed the lack of maintenance prior to the devastation. For example, she added: “KZN has a serious water and sanitation challenge, which was amplified by the floods. Poor

He acknowledged the importance of raising competency levels in the public and private sectors to achieve the necessary progress.

Soluade stated: “As engineers, we are called upon to make a difference.”

This viewpoint was reinforced by Lavern Moodley, chief civil engineer at eThekwini Transport Authority. He said there was a

need for stakeholders to work together in planning for the future of transportation in the region. He also took the opportunity to discuss various projects undertaken by the authority to enhance traffic flow in KZN’s largest city.

Meanwhile, Mabuyi Mhlanga, programme manager: N2, Sanral, shared details about the plans and projects being undertaken by the state-owned entity. This included how Sanral is actively promoting the inclusion of SMMEs in the construction industry by providing opportunities for them to participate and contribute to projects, particularly on the N2/N3 upgrade programme, which she indicated is expected to take 60 months to complete at a budget of R5 billion.

Attendees also had the opportunity to ask pertinent questions, which predominantly revolved around funding mechanisms, project timelines, stakeholder engagement, sustainability considerations, and plans for transportation and road networks.

“In a nutshell, CESA’s mandate is to lobby for positive change within the regulatory environment to enable our members to better serve society,” Soluade concluded.

The Cornubia interchange in Mount Edgecombe was designed to facilitate economic development within the eThekwini region IMIESA June 2023

45

An aerial view of the site, with a section of the 630 mm diameter HDPE pipe. This measured 85 m in length once fully assembled

Countering micro flooding on Innes Road Installing underground services in urban environments requires detailed planning to minimise disruptions. A case in point is a complex stormwater project carried out for eThekwini Metropolitan Municipality, where horizontal directional drilling (HDD) proved to be the optimal approach in upgrading a network section along Innes Road in Morningside, Durban.

O

ne of the hilliest areas within the city, the topography poses grade challenges, as well as various site constraints, which had to be carefully assessed and managed. These included positioning the HDD rig within the tight space available, and the need to drill alongside or under a series of buildings and structures along the route. Another key challenge was the need to drill under the cantilever foundation of a retaining wall running adjacent to approximately 80% of the drill line.

“However, the most challenging aspect of the works was tying up the levels at the entry and exit pits across the 17 m fall of the drill grade,” explains Byron Field, director, BLOC Contractors. BLOC

46 IMIESA June 2023

was appointed as the main contractor to execute the HDD programme on behalf of the eThekwini Roads and Stormwater Department.

The drilling programme required the installation of the main stormwater trunk, which comprises a PN10 630 mm diameter HDPE pipe measuring 85 m in length. This now links all the properties in the immediate area with the city’s new main stormwater bulk line.

Technical aspects “There were some interesting technical challenges on this drill that required some innovative thinking from all members of the team and the application of an array of skills to ensure the job was delivered,” Field explains.

Some of the challenges included: • the drill length itself, which was in the order of about 120 m in length Final reamer connected to the 630 mm bullnose ready for pull-through

TRENCHLESS TECHNOLOGY Innes Road vertical profile

Innes Road horizontal profile

One of the key challenges was the need to drill under the cantilever foundation of a retaining wall that ran adjacent to approximately 80% of the drill line

• a 630 mm to 315 mm pipe reducer designed and built by RHO-Tech • a 10 000 ℓ water tank installed to ensure a constant supply of water to make the drilling mud • mud management using a combination of a TLB, 5 m3 tipper lined with plastic, and a vacuum pump.

Piloting phase

• the drill grade, which was down a slope of approximately 10% • the drill time required and the need to keep the drill head lubricated • the excessive mud produced and the need to manage this • the management of the traffic on busy Innes Road.

Some of the solutions applied included: • the design of a vertical and horizontal site profile to help manage the drill line (see Figure 1 and 2) • a 4 m deep pit constructed by BLOC for the changing of reamers and removal of the pullers • a 315 mm puller specially engineered and manufactured by HDD Engineers The HDPE stormwater pipe snaking through a section of the congested site in Morningside, Durban, in preparation for installation

The piloting process required a dedicated focus as the constraints had to be avoided both vertically and horizontally, while maintaining the correct grade throughout the drill programme.

“Furthermore, the drill had to enter pit 1 at the right location and exit at the right location at pit 2. This was not immediately achieved, as the retaining wall proved challenging as we navigated around the foundations, but after two days of careful and patient drilling we succeeded,” Field continues.

Reaming and pipe pull-back The scope required the drill team to ream to a diameter of 800 mm, which also proved to be an intensive process, taking five days to complete. During this time, the mud produced had to be constantly collected and sent to an acceptable disposal site.

“The pipe pull-back was the only day we needed full road closure. Always the

most stressful part of the HDD process, we prepped for road closure and then got the pipe in place. After tightly connecting the reamer and puller, the pull-back process began and was concluded by day’s end,” Field explains.

Recognising that most of the drilling mud had been drained, BLOC’s main concern was that there would be a cavity between the 630 mm diameter pipe and the 800 mm ream. Since the specification clearly ruled out any evidence of settlement on any of the constraints or structures, it was decided to grout the pipe in.

A job well done In the end, the project was successfully concluded on time, within budget and to the client’s satisfaction, with all the support networks in place.

As Field points out, the project’s ultimate success was based on exceptional teamwork and proactive stakeholder engagement. For eThekwini, it’s also a proven case study on how effective HDD is a trenchless option for complex works in densified urban areas.

“Growing the trenchless construction industry in South Africa is a major focus for BLOC – not only for our business to succeed, but for the development of a skills and technology base that can serve to ensure the better delivery of infrastructure projects across the country,” Field concludes.

IMIESA June 2023

47

CEMENT & CONCRETE

CONCRETE’S EXCEPTIONAL FIRE RESISTANCE BASED ON UNIQUE PROPERTIES In the design and construction of buildings and structures, the preservation of life and prevention of injury due to fire are the most critical considerations – apart from minimising damage to the structure itself – says John Roxburgh, technical specialist: School of Concrete Technology, Cement & Concrete SA.

R

oxburgh says approaches taken to mitigate fires in buildings are multifaceted and include active measures such as smoke detectors, fire alarms, sprinkler systems, smoke extraction and evacuation protocols. Passive measures include fire containment through fireresistant walls, roofs, floors and the installation of fire doors, along with clear signage to show accessible fire escape routes.

“An important component of fire engineering is to prevent the spread of fire within a building. By containing the fire, further damage to the building is prevented while minimising the heat build-up and deadly smoke emissions. Concrete is an excellent building material to use for the containment of fire,” Roxburgh explains.

He says concrete is: • non-combustible and consequently will not add to the fire load • does not produce toxic smoke or drip hot molten material • retains its structural strength under most fire conditions.

“Concrete’s fire resistance is based on its unique composition and physical properties.

It is made from a mixture of cement, water and aggregates.

These components combine to make a material with low thermal conductivity, which allows the concrete to shield other parts of the building from the heat. Even after prolonged exposure to fire, the internal concrete temperatures can remain low to both prevent the spreading of fire and protect the steel reinforcement embedded in the concrete,” Roxburgh continues.

Roxburgh says at temperatures above 300°C, concrete will start to lose its strength. But even then, high temperatures are typically localised at the surface of the concrete, with the core concrete retaining its structural integrity. This is important to prevent sudden and catastrophic collapse.

Spalling A1 building material Concrete also does not need any fireprotective coating and can slow down the transfer of heat in a building. For all these reasons, it is classified as an A1 building material, which represents the highest grade of fire resistance under the stringent European Standards.

At very high temperatures, the surface of the concrete can spall; at times, this can be explosive, depending on the rate of heat build-up. Spalling is caused by the residual water in the concrete turning to expansive steam. To control this in areas where spalling may occur – such as in traffic tunnels – polypropylene fibres can

be included in the concrete mix. The fibres melt under high temperatures to provide space for the steam to expand into.

“Most concrete buildings are not completely destroyed by fire and, in many cases, there is no adverse effect on the structure’s loadbearing capacity. Not having to demolish and replace the building means it is possible for repairs and reoccupation to take place quickly. This gives obvious economic benefits to the property owner, including reduced insurance premiums,” Roxburgh explains.

For this reason, it is not surprising that concrete is regarded as the ideal building material for factories, warehouses and power plants, particularly those with flammable materials or machines operating at high temperatures.

Mix design flexibility Additionally, concrete can be manufactured to an extensive range of specifications to suit a wide variety of requirements and applications by using different mix designs or adding different materials in the concrete mix.

“Concrete offers both aesthetic appeal and economy. Its strength, durability and natural thermal mass produce structures that require low maintenance, while providing high durability with economical energy efficiency,” adds Roxburgh.

“It is by far the most economical building solution based on initial cost, long-term durability, energy efficiency, low maintenance and operational costs, as well as opportunities for future modification and reuse should the occupancy of the building change,” Roxburgh concludes.

THE SCHOOL OF CONCRETE TECHNOLOGY Contact the SCT to discuss the best concrete technology educational path for you +27 (0)11 315 0300 | sct@cemcon-sa.org.za | www.cemcon-sa.org.za

CEMENT & CONCRETE Since 1990, AfriSam has reduced its CO2 emissions per tonne of cementitious material by 33%

Reinstating an industrial floor to a pristine finish

O The evolution of green construction

T

he sustainability drive in the construction sector is gathering momentum, with AfriSam’s product range evolving to meet current and future trends in areas like green building.

According to Hannes Meyer, cementitious executive at AfriSam, the company has made continuous progress in fields such as energy efficiency, cement extenders, water conservation and biodiversity.

This allows customers to procure products in the knowledge that the environmental and carbon impact is minimised.

“We give our customers the opportunity to support a more sustainable future for the sector by choosing construction materials that embody this commitment,” Meyer explains. “We do not just set theoretical targets for environmental performance; we are practical about what we can achieve, because we have been innovating on this front for so long.”

This is in clear contrast to a significant level of ‘greenwashing’ in this sector, where many companies advertise a sustainable approach but without credible evidence of how their targets are to be achieved.

Since 1990, AfriSam has been able to reduce the volume of carbon dioxide emissions per tonne of cementitious material by 33%.

ver time, the concrete flooring at DGB’s Franschhoek Cellar production facility had succumbed to wear and tear, requiring an intensive overhaul. The contract was awarded to Botwei Projects, with the client brief requiring the execution of a high-quality, granite-grey finish.

On initial inspection, it was found that the existing floor was curling, delaminating and riddled with bad joint specifications. This led to the decision to strip 1 700 m2 of existing cementitious flooring and start from scratch. Additionally, the client required a further 400 m2 of new flooring to be installed. On all phases, Sika’s specialist solutions were specified to ensure the best result.

Botwei Projects began with the preparation of the existing floors using Sikadur-52 ZA to seal all existing cracks by means of gravity feed. During this process, a bead of sealant is used to create a reservoir around the cracks, which are filled with the low-viscosity resin, creating a robust permanent seal.

In turn, SikaGrout-212 was used to fill all voids and defects.

The latter is a high-strength cementitious grout with shrinkage compensation properties and is the go-to product on repair projects where high-strength concrete is required. Additional repairs were undertaken using SikaQuick-2500, which, true to its name, promotes very rapid hardening, enabling early strength gain.

Final touches In the next stage, Sikafloor-20 PurCem was trowel applied at 6 mm.

A high-strength polyurethane cement hybrid screed, this product is odourless, non-tainting when used in food processing areas, and thermal shock-resistant when used in Industrial freezers.

Finally, Sika Primer-3N and Sikaflex PRO-3 polyurethane joint sealant were used to prime and seal the joints.

All in all, the project not only met and exceeded the customer’s brief, but it also provided an elegant floor to match the world-class winery in which it resides.

Sustainability journey In a carbon-intensive industry like cement manufacturing, it is difficult to reduce the carbon impact without a depth of expertise and constant investment in innovation, says Marieta Buckle, process engineer, AfriSam. It is also important to consider the cost implications of any changes, given South Africa’s need for a just transition to a sustainable future.

“In our position as a developing country, our future will demand the construction of millions of houses – structures that require considerable quantities of cement,” says Buckle. “The way we pursue our just transition must take into account the affordability of these homes for the vast majority of citizens.”

AfriSam has therefore been cautious in how it sets and publicises its sustainability targets, while all along continuing to prioritise research and development into how to achieve lower-carbon products. Having considered a wide variety of options available, it has implemented strategies that have the least cost impact on customers and the market.

Sika’s Sikafloor-20 PurCem polyurethane hybrid screed superseded the client’s expectations with its robust, yet elegant and durable finish

IMIESA June 2023

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IMESA MESA

IMESA AFFILIATE MEMBERS PROFESSIONAL AFFILIATES

AECOM siphokuhle.dlamini@aecom.com AFI Consult banie@afri-infra.com Alake Consulting Engineers lunga@alakeconsulting.com ARRB Systems info@arrbsystemssa.com Asla Construction (Pty) Ltd johanv@asla.co.za BMK Group brian@bmkgroup.co.za Bosch Projects (Pty) Ltd mail@boschprojects.co.za BVI Consulting Engineers marketing@bviho.co.za CCG puhumudzo@ccgsytems.co.za / info@ccgsystems.co.za Corrosion Institute of Southern Africa secretary@corrosioninstitute.org.za Dlamindlovu Consulting Engineers & Project Managers info@dlami-ndlovu.co.za EFG Engineers eric@efgeng.co.za Elster Kent Metering Mark.Shamley@Honeywell.com EMS Solutions paul@emssolutions.co.za ERWAT mail@erwat.co.za ESCONGWENI BPH ENGINEERS (PTY) LTD info@escbph.co.za Gabion Baskets mail@gabionbaskets.co.za GIBB marketing@gibb.co.za GIGSA secretary@gigsa.org GLS Consulting info@gls.co.za Gorman Rupp Cordeiro@gormanrupp.co.za Gudunkomo Investments & Consulting info@gudunkomo.co.za Hatch Africa (Pty) Ltd info@hatch.co.za HB Glass Filter Media info@hardybulkinglass.com Herrenknecht schiewe.helene@herrenknecht.de Huber Technology cs@hubersa.com Hydro-comp Enterprises info@edams.co.za Infrachamps Consulting info@infrachamps.co.za INFRATEC info@infratec.co.za IQHINA Consulting Engineers & Project Managers info@iqhina.co.za iX engineers (Pty) Ltd hans.k@ixengineers.co.za Izinga Holdings info@izingalabezi.co.za JBFE Consulting (Pty) Ltd issie@jbfe.co.za JG Afrika DennyC@jgafrika.com KABE Consulting Engineers info@kabe.co.za Kago Consulting Engineers kagocon@kago.co.za Kantey & Templer (K&T) Consulting Engineers ccherry@ct.kanteys.co.za Kitso Botlhale Consulting Engineers info@kitsobce.co.za KSB Pumps and Valves (Pty) Ltd salesza@ksb.com KUREMA Engineering (Pty) Ltd info@kurema.co.za Lektratek Water general@lwt.co.za Loshini Projects muzi@loshini.co.za Makhaotse Narasimulu & Associates mmakhaotse@mna-sa.co.za Mariswe (Pty) Ltd neshniec@mariswe.com Martin & East gbyron@martin-east.co.za M & C Consulting Engineers (Pty) Ltd info@mcconsulting.co.za Mhiduve adminpotch@mhiduve.co.za MPAMOT (PTY) LTD mpumem@mpamot.com Mvubu Consulting & Project Managers miranda@mvubu.net Nyeleti Consulting naidoot@nyeleti.co.za Odour Engineering Systems mathewc@oes.co.za Prociv Consulting & Projects Management amarunga@prociv.co.za Rainbow Reservoirs quin@rainbowres.com Re-Solve Consulting (Pty) Ltd maura@re-solve.co.za Ribicon Consulting Group (Pty) Ltd info@ribicon.co.za Royal HaskoningDHV francisg@rhdv.com SABITA info@sabita.co.za SAFRIPOL mberry@safripol.com SAGI annette@sagi.co.za SALGA info@salga.org.za SAPPMA admin@sappma.co.za / willem@sappma.co.za SARF administrator@sarf.org.za.co.za SBS Water Systems marketing@sbstanks.co.za Silulumanzi Antoinette.Diphoko@silulumanzi.com Siroccon International (Pty) Ltd admin@siroccon.co.za SiVEST SA info@sivest.co.za Sizabantu Piping Systems (Pty) Ltd proudly@sizabantu.com Siza Water (RF) Pty Ltd PA@sizawater.com Sky High Consulting Engineers (Pty) Ltd info@shconsultong.co.za SKYV Consulting Engineers (Pty) Ltd kamesh@skyv.co.za Smartlock jp.alkema@smartlock.net SMEC capetown@smec.com SOUTH AFRICAN VALUE EDUCATION Sabiha@savegroup.co.za Southern African Society for Trenchless Technology director@sasst.org.za SRK Consulting jomar@srk.co.za Star Of Life Emergency Trading CC admin@staroflife.co.za TPA Consulting roger@tpa.co.za V3 Consulting Engineers (Pty) Ltd info@v3consulting.co.za VIP Consulting Engineers esme@vipconsulting.co.za VNA info@vnac.co.za Water Institute of Southern Africa wisa@wisa.org.za Wam Technology CC support@wamsys.co.za Wilo South Africa marketingsa@wilo.co.za WRCON ben@wrcon.co.za WRP ronniem@wrp.co.za Zutari Rashree.Maharaj@Zutari.com

VEHICLES & EQUIPMENT

Class-leading trommels added to ELB line-up

M

DS track, static The M515 heavy-duty and recycling trommel is ideal for cleaning dirty material and can handle trommels, as well rocks up to 800 mm in size as apron feeders, are designed to handle a wide range of media that include blasted rock, riprap, as well as varying substrates such as clay, limestone and even recycled concrete rubble. But, most importantly, it’s their enhanced processing efficiencies and ability to handle oversize materials that makes Terex Corporation’s MDS brand a market leader.

Locally, the MDS range will be sold and supported by ELB Equipment, which is also currently the dealer for Terex’s Powerscreen scalper and screen series.

From an operational perspective, trommels pass on major production benefits given their ability to separate up to four streams of aggregates quickly and efficiently. The process starts with the separation of soil and fines at the feed-end, moving through to larger rocks and oversize rock up to 1.5 m at the discharge end.

In terms of performance, MDS’s heavy-duty static trommel units are capable of processing 500-750 tonnes per hour (tph), while its tracked trommels deliver in a range of 300-750 tph, depending on the model.

Typical applications include quarrying, sand and gravel operations, and recycling.

The latter application is a growing market, particularly for construction and demolition waste processing. Here, they aid in separating and sorting different types of recyclable materials, such as wood, plastics, metals and aggregates that could otherwise end up in a landfill.

Trommels have the ability to separate up to four streams of aggregates quickly and efficiently

IMIESA June 2023

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VEHICLES & EQUIPMENT

Island runway rehabilitation Located in the western Pacific Ocean, some 1 500 km due east of the Philippines, Yap International Airpor t is undergoing extensive rehabilitation to cater for connections to Guam and Palau. The project star ted in April 2022 for scheduled completion around April 2024.

C

entral to the project is GPPC Inc’s Lintec CSD2500B containerised asphalt mixing plant, which was set up on-site in January 2023.

This will produce the approximately 26 000 tonnes of hot mix asphalt required to resurface the 1 950.72 m long and 60.96 m wide runway.

An ideal choice for both small and big projects, the CSD2500B provides an output of up to 160 tph in 2 500 kg batches.

During this process, its double screen drum technology combines the heating and screening of aggregates in a single unit.

This eliminates the need for a hot elevator and vibrating screens, greatly reducing fuel consumption and maintenance.

islands,” says Jefferson Gayas, project manager, GPPC Inc. “Getting hold of quality materials can be difficult, and equipment is often in short supply. It’s also rare for projects or consecutive jobs to take place on the same island, so the ease with which the CSD2500B can be relocated makes that task much less of a headache.”

An expanding OEM footprint Manufactured and supplied worldwide, the Lintec CSD2500B forms part of a comprehensive line-up produced by Lintec & Linnhoff, which has helped to deliver some of the world’s most prominent construction achievements. These include the Hong

Jefferson Gayas, project manager, GPPC Inc., with the Lintec CSD2500B at the jobsite on the Yap islands

Kong-Zhuhai-Macau bridge; Yas Marina Circuit, Abu Dhabi; The Palm Island, Dubai; Storebaelt Bridge, Denmark; Merdeka 118 Tower, Malaysia; and the first polder project in Singapore.

The Lintec CSD2500B containerised asphalt mixing plant provides an output of up to 160 tph in 2 500 kg batches

Ease of mobility and setup Once delivered to the jobsite by land or sea, the rigid nature of the containers also significantly lowers plant setup costs due to their high stability on suitably compacted soil.

In these instances, a concrete foundation is not required. Then from an operational viewpoint, their enclosed structure provides a clean and tidy industrial appearance, while also enhancing security via a single, lockable main access door.

“There are several unique, major challenges that are present when working on remote

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48

Rand Water

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Sizabantu Piping Systems

IFC

SMEC South Africa

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52 IMIESA June 2023

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Creating Concrete Possibilities