IMIESA January 2020

www.infrastructurenews.co.za

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

I N F R A S T R U C T U R E D E V E LO P M E N T • B U I L D I N G • M A I N T E N A N C E • S E RV I C E D E L I V E RY

Innovation drives Drakenstein PAT station Roads & Bridges

The road funding conundrum

Geotechnical Engineering The DIP advantage

Cement & Concrete Levelling the cement playing fields

Environmental Engineering Repairing a flooddamaged spillway

ISSN 0257 1978

V o l u m e 4 5 N o . 0 1 • J a n u a r y 2 0 2 0 • R 5 5 . 0 0 ( i n c l . VAT )

INSIDE

VOLUME 45 NO. 01 JANUARY 2020 www.infrastructurenews.co.za

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

I N F R A S T R U C T U R E D E V E LO P M E N T • B U I L D I N G • M A I N T E N A N C E • S E RV I C E D E L I V E RY

Innovation drives Drakenstein PAT station Roads & Bridges

The road funding conundrum

Geotechnical Engineering

The DIP advantage

Cement & Concrete Levelling the cement playing fields

Environmental Engineering Repairing a flooddamaged spillway

ISSN 0257 1978

V o l u m e 4 5 N o . 0 1 • J a n u a r y 2 0 2 0 • R 5 5 . 0 0 ( i n c l . VAT )

Deemed a first of its kind in South Africa, the award-winning Leliefontein Pump-As-Turbine Station in Drakenstein Municipality generates electricity while transferring water. P6

22

ROADS & BRIDGES | CAPSA Rising above the floods

Regulars

Social Labour Plans

Editor’s comment President’s comment Africa round-up Index to advertisers

3 5 10 55

Cover Story Innovation drives Drakenstein PAT station

6

Geotechnical Engineering The DIP advantage Definitive geotechnical work unveils bumper edition

12 15

Information Technology Preventing ransomware attacks

16

Municipal Focus Nelson Mandela Bay heading for Day Zero?

35

Environmental Engineering Retaining the sea 36 Repairing a flood-damaged spillway 38

Dams & Water Storage 40

Urban flood control

Cement & Concrete Levelling the cement playing fields Five costly housing errors to avoid Profit above quality Auditing integrated operations Marine protection for Point Promenade

42 44 45 46 47

Water Management 17

Pipes, Pumps & Valves Demand grows for plastic pipes Fight losses with pressure reduction

Giving back to communities

18 21

The need for a new approach

48

Transport, Logistics, Vehicles & Equipment Accelerating concrete paving projects Bomag provides the competitive edge

51 52

Roads & Bridges | CAPSA

36 29

WATER & WASTEWATER Improving water resilience: a private sector perspective

Rising above the floods 22 Designing with statistical certainty 24 The road funding conundrum 26

Building Materials

Water & Wastewater

Industry News

Improving water resilience: a private sector perspective 29 Reuse schemes a win-win for PPPs 33 Securing our water resources 34

Energy

42

CEMENT & CONCRETE Levelling the cement playing fields

Face brick forms part of iconic design

53

Semane welcomes new CEO

Run-of-river power

51

54

55

TRANSPORT, LOGISTICS, VEHICLES & EQUIPMENT Accelerating concrete paving projects

IMIESA January 2020

1

Joint Conference with

IMESA & IAWEES Institute of Municipal Engineering of Southern Africa & International Association of Water, Environment, Energy and Society

EVENT: VENUE: DATES: THEME:

84TH IMESA Conference in collaboration with IAWEES Cape Town International Convention Centre 28-30 October 2020 Synergy through Engineering

Earn 2.5 CPD points by attending

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EDITOR’S COMMENT

A turning point

MANAGING EDITOR Alastair Currie SENIOR JOURNALIST Danielle Petterson JOURNALIST Nombulelo Manyana HEAD OF DESIGN Beren Bauermeister CHIEF SUB-EDITOR Tristan Snijders CONTRIBUTORS Pieter Gouws, Belinda Herbst, Randeer Kasserchun, Kyle Poolman, Konrad Röhrs, Herman Smit, Simeon Tassev, Peter Townshend, Hanine van Deventer PRODUCTION & CLIENT LIAISON MANAGER Antois-Leigh Botma PRODUCTION COORDINATOR Jacqueline Modise GROUP SALES MANAGER Chilomia Van Wijk BOOKKEEPER Tonya Hebenton DISTRIBUTION MANAGER Nomsa Masina DISTRIBUTION COORDINATOR Asha Pursotham SUBSCRIPTIONS subs@3smedia.co.za PRINTERS Novus Print KZN +27 (0)31 714 4700 ___________________________________________________

W

elcome to 2020, a year that will be definitive for South Africa’s infrastructure economy and the interconnecting industries that all achieve their end goals via the broader construction industry. I’m confident we will see an upturn, the extent of which will be dependent on how the three tiers of government communicate and collectively execute tasks.

In Q4 2019, we witnessed mayoral changes in the metros of Johannesburg, Nelson Mandela Bay and Tshwane. It is critical that the final management teams are aligned and non-political when it comes to infrastructure delivery and investor confidence. Within the mix, the Department of Trade and Industry (DTI) is also crucial in protecting and stimulating the local economy. That includes interventions for essential industry lobby groups against uncompetitive trade.

A prime example is the approach being taken by The Concrete Institute (TCI), representing its cement manufacturing members, to counter the rising volume of imports from Asian countries, some of which may not be compliant. Either way, these imported products are around 45% cheaper than locally produced cement. It’s an untenable situation, especially since importers are not invested in South Africa and don’t have to comply with local legislation and taxation.

TCI has applied to the International Trade Administration Commission of South Africa (ITAC) for a safeguard action. If the ITAC agrees, this will impose a general tariff on all imported cement. Additionally, TCI has applied to the DTI for designation status. Sectors that are designated must have a specified percentage of local content. If approved, all government-funded projects will have to buy local cement.

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

PUBLISHER Jacques Breytenbach 3S Media 46 Milkyway Avenue, Frankenwald, 2090 PO Box 92026, Norwood 2117 Tel: +27 (0)11 233 2600 www.3smedia.co.za ANNUAL SUBSCRIPTION: R600.00 (INCL VAT) ISSN 0257 1978 IMIESA, Inst.MUNIC. ENG. S. AFR. © Copyright 2019. 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: Ingrid Botton Tel: +27 (0)31 266 3263 Email: imesakzn@imesa.org.za NORTHERN PROVINCES Secretary: Ollah Mthembu Tel: +27 (0)82 823 7104 Email: np@imesa.org.za

Government interventions National Treasury and associated departments like Auditor-General South Africa, Salga and Cogta are respectively all well aware of the facts concerning state-owned entity (SOE) and municipal performance.

They are all drilling down into underperforming bodies in a proactive way that is very encouraging. We won’t see it in the 2019/20 results, but hopefully good performance will be non-negotiable by 2020/21.

SOUTHERN CAPE KAROO Secretary: Henrietta Olivier Tel: +27 (0)79 390 7536 Email: imesasck@imesa.org.za WESTERN CAPE Secretary: Michelle Ackerman Tel: +27 (0)21 444 7114 Email: imesawc@imesa.org.za FREE STATE & NORTHERN CAPE Secretary: Wilma Van Der Walt Tel: +27 (0)83 457 4362 Email: imesafsnc@imesa.org.za All material herein IMIESA is copyright protected and may not be reproduced either in whole or in part without the prior written permission of the publisher.

The views of the authors do not necessarily reflect those of the Institute of Municipal Engineering of Southern Africa or the publishers. _____________________________________________ Novus Holdings is a Level 1 Broad-Based Black Economic Empowerment (BBBEE) Contributor, with 135% recognised procurement recognition.

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SOEs are traditionally major infrastructure investors, but maladministration across the board has negated this. Masses of tenders have been issued, but in many cases not effectively due to supply chain and service provider irregularities. That hopefully ends in 2020. For many SOEs, their future may depend in part on public-private partnerships (PPPs).

Business rescues The employee stress levels within SOEs are building and they need revitalisation plans that work. Eskom is a far more complex challenge to solve, and we’ll see how this unfolds in 2020 and beyond. South African Airways (SAA) is potentially a more workable and immediate example that could be remodelled faster.

SAA has been in operation since 1934 and is our proud carrier and an ambassador for South African tourism. The fact that it went into business rescue was an essential step to stem sustained losses and does not detract from the exceptional pilots and crew members that man these aircraft. It comes down to historical deficiencies in public sector management.

Hopefully, in 2020, the SAA brand will survive as a revitalised and PPP-owned national airline that takes us forward.

Within the private space, the same is true for those employed in some of South Africa’s most prestigious construction companies, celebrating decades of excellence, but now under business rescue and possible extinction. Leading consulting firms are also feeling the pinch and face similar pressures. These businesses also need protection and support, given that construction is a major GDP contributor.

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.

struct www.infra

urenews.co

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.za

Infrastructure News

magazine The official of the Institute Engineerin g of Municipal Africa of Southern

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floodRepair ing a y damag ed spillwa

1978 ISSN 0257

n c l . VAT ) R55.00 (i y 2020 • • Januar 5 No.01 Vo l u m e 4

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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 January 2020

3

Joint Conference with

IMESA & IAWEES Institute of Municipal Engineering of Southern Africa & International Association of Water, Environment, Energy and Society

CALL FOR ABSTRACTS for paper and poster presentations

THEME

SYNERGY THROUGH ENGINEERING

CATEGORIES • Environment

• Energy

• Water and Sanitation

• Financial, Legal and Regulatory

• Transport, Roads

• Data management

and Stormwater

A B S T R AC T S S U B M I T T E D BY

06 March 2020 (poster presentations and abstract submissions)

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

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

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IMESA The Institute of Municipal Engineering of Southern Africa & International Association of Water, Environment, Energy and Society

CONFERENCE ENDORSED BY

PRESIDENT’S COMMENT

IMESA

Rules of engagement

W

elcome to 2020 – a year that brings with it a host of new oppor tunities.

The world over, it’s an exciting time to be a municipal engineer, whether in the developed or developing world. Cities and their urban populations keep growing, with a corresponding demand for infrastructure ser vices. Therefore, the demand for construction professionals should be exponential, but that’s interdependent on an enabling environment and adequate financial resources.

In the South African context, we have access to skills and funding, but their implementation is severely constrained for all the wrong reasons. Key ones include wasteful expenditure, maladministration, and a growing debt burden, all of which threaten to over whelm many of our municipalities.

Compounding the problem is a prevailing culture of non-payment for key ser vices like electricity and water. Illegal connections are another factor; even when prepaid meters are installed as a countermeasure, they are frequently tampered with and bypassed.

With national government inter vention and municipal policing, we can put a halt to underper forming municipalities and turn them around. However, combating non-payment may be a bit more challenging. This behaviour requires ongoing community engagement to clearly show that non-payment is selfdestructive. It negatively impacts on ser vice deliver y and economic growth, destroys jobs and creates heightened health, safety and security issues. It also leaves our municipal managers and engineers with a sense of powerlessness. 2020 is the year to put a stop to this.

Knowledge is power As IMESA, we’ve always focused on continuous professional development. But given the challenges, we understand that our role has become far greater than this. We need to step into the breach and become more proactive and operational.

We’ve been invited by Salga and Cogta to work jointly to help address engineering and technical skills gaps. At our October 2019 conference, National Treasur y also indicated its willingness to engage and assist in procurement training. IMESA has called for senior-level discussions with all three organisations. Hopefully, these will be convened in early Februar y.

Membership drive There’s never been a more important time to join IMESA, the industr y association that represents your sector. This view is supported by the steady growth in membership applications. We received around 160 alone at the 2019 IMESA Conference.

During Februar y and March, I will be visiting regional IMESA branches where I look for ward to engaging with members and supporting efforts to recruit new ones.

One of our goals is to work with branches and help them formulate specific training and development plans. Where practical, IMESA will then provide an enabling framework.

Examples include regional training workshops, like those held in 2019 in Durban, Kimberley, Nelspruit and Newcastle. These workshops were well received and will be extended to other national centres in 2020.

IMESA 2020 Conference

way for the 84th IMESA Conference, themed ‘Synergy Through Engineering’. This year’s event will be co-hosted by the International Association of Water, Environment, Energy and Society (IAWEES). It’s always rewarding and relevant to share global best practices, especially where these can be applied locally.

The Call for Abstracts opens on 13 March 2020 and there are six broad categories, namely: - Data management - Energy - Environment - Financial, legal and regulatory - Transport, roads and stormwater - Water and sanitation.

Our 2019 conference stimulated some of the most open and proactive debates to date.

The 2020 one will be even more engaging, as participants press for collective solutions.

Randeer Kasserchun, president, IMESA

In the meantime, preparations are well under

IMIESA January 2020

5

COVER STORY

Innovation drives Drakenstein PAT station

Aerial photograph of Leliefontein reservoir with the pump station in the foreground

Deemed a first of its kind in South Africa, the Leliefontein Pump-As-Turbine Station in Drakenstein Municipality generates electricity while transferring water.

O

riginally intended to be a booster station to supply water to Wellington during summer peak demand, Leliefontein’s location within Drakenstein The Leliefontein PAT Station has won numerous awards: • 2019 CESA Award for projects with a value of less than R50 million • 2018 SAICE National Projects Division award for the most outstanding civil engineering project for water engineering • innovation award at the 2019 Greenest Municipality Competition (Western Cape)

Municipality’s bulk water network is prime for a productive mini hydropower station.

While using pumps-as-turbines (PATs) is not a new technology, Leliefontein uniquely uses the same set of pumps to pump water and generate electricity by reversing flow through the pumps. This is achieved by the innovative use of active front-end variable-speed drives (AFE VSDs) to lower the speed of the PATs to generate electricity at the available flow rates, a series of actuated valves, and some creative pipework. The power generated at the station is fed back into the municipal grid, offsetting the power consumed during pumping.

Purpose of the project The bulk water supply to Drakenstein

6

IMIESA January 2020

Hein Henning, engineer: Water Operations, Drakenstein Municipality

COVER STORY

comes from the Wemmershoek Water Treatment Works to Leliefontein reser voir in Paarl. It consists of a 100 Mℓ and 36 Mℓ reser voir, ser ving the town of Paarl.

This gravity pipeline also supplies water to Wellington’s Con Marine and Newton zone reser voirs, at a maximum capacity of 19 Mℓ/day.

There are periods when the supply from Wemmershoek is interrupted, either due to planned maintenance or unplanned repair work. When this occurs, water from the Leliefontein reser voirs can gravitate towards Wellington at a maximum capacity of 11.2 Mℓ/day. According to Hein Henning, engineer: Water Ser vices Operations, Drakenstein Municipality, this

Leliefontein operation in turbine mode

ABOVE Pump station entrance ABOVE RIGHT Pump station inside – below normal ground level RIGHT Actuator controls above normal ground level

capacity is currently sufficient to meet Wellington’s winter demand, but not its summer demand.

The upgrading of the Leliefontein-toWellington supply system was included in Drakenstein Municipality’s bulk water masterplan and a pump station was identified as the most suitable method to increase the conveyance capacity to 30 Mℓ/day. However, the initial plan meant that the pump station was only going to

be used a few weeks in the year, with the pumps standing idle most of the time. A new plan had to be made to utilise the installation for most of the year.

Solving the problem “Drakenstein Municipality appointed Aurecon Consulting Engineers to assist with solving the problem and many brainstorming hours were spent to come up with a solution. The PAT concept was eagerly adopted by all parties and the crunch time to get the correct design, technology, equipment and approvals started,” says Henning.

“The budget was also a major factor to be considered. Due the topography of the Leliefontein reser voir site, the pumps would have to be installed below ground to ensure sufficient suction head.”

A PAT is essentially a centrifugal pump, which can be used as a turbine by reversing the direction of water flow through the pump and reversing the rotation of the pump shaft. An options analysis determined PAT to be the preferred turbine option for this installation because it offered

IMIESA January 2020

7

COVER STORY

the PATs had to be reduced to 30 Hz or approximately 900 rpm to achieve this.

It was decided to change the singlequadrant VSDs required for pumping to AFE VSDs. The AFE drives allowed for fourquadrant operation, meaning they could change the speed of the PATs in pump and generation modes as well as allow discharge of power into the grid at the required power quality. This solved the problem of having to slow down the PATs to allow them to generate electricity at the available residual pressure.

Construction contracts

Motor control centre with generator in the backroom

several advantages, including lower capital costs, no increase in footprint of the pump station, ease of maintenance, and utilisation of off-the-shelf equipment.

Pump station design The main objective of the project was to design and build an efficient and easily upgradable pump station. The design approach for the pump station is as follows: • three end-suction centrifugal pumps in two duty/one standby configuration, with allowance for a fourth pump in future; each pump supplied with a 185 kW fourpole induction motor • stainless steel suction and deliver y pipework, with suction and deliver y isolation valves and discharge nonreturn valves • a motor control centre (MCC) equipped with three 185 kW VSDs (with spare cubicle for future drive), logic controller for automatic control and monitoring of the installation, and changeover compartments for the mains and backup generator power • 550 kVA diesel standby generator for

8

IMIESA January 2020

backup power during pumping •1 MVA transformer for bulk power supply • radio telemetr y and monitoring SCADA at the municipal offices • u nderground HDPE suction (DN900, drawing from Leliefontein reser voirs) and deliver y (DN630, pumping into the existing DN500/450 AC pipeline towards Wellington) pipelines, with of ftake isolation valve chambers • pump station building to house the pumps, MCC room and diesel generator with LED lighting • e lectrified security perimeter fence, including access gates and paved access road to the pump station.

Challenges of converting pump to PAT The generated power quality (frequency, voltage and power factor) and per formance of the PAT station in generation mode had to comply with the South African Grid Code and Drakenstein Municipality by-laws. The frequency of electricity in the network is 50 Hz but, with the available water pressure, it could not be achieved by the PAT system.

By slowing down the rotational speed of the PATs, it allowed the system to generate electrical power at the available residual pressure. It was found that the speed of

The civil works and the mechanical and electrical works were put out as two separate contracts, with Aurecon managing the tendering and contract administration on behalf of Drakenstein Municipality.

The civil contract, under taken by JVZ/Vakala Construction, was completed in September 2017.

The mechanical and electrical contract, with Hidro-Tech Systems as main contractor, commenced in Januar y 2017, with most of the installation works completed in Februar y 2018. The subcontractor to HidroTech for the electrical part was Black Arc Electrical and Spectrum Communications was responsible for the SCADA and telemetr y. The pumps were supplied by KSB and the electrical motors by Motorelli.

The pump station is currently fully operational and producing clean electricity delivered directly into the municipal electrical network.

“Leliefontein is a true marriage between the civil, mechanical and electrical engineering disciplines, and ser ves as an example of how municipalities can use low-cost, off-the-shelf equipment like centrifugal pumps and induction motors to generate clean power using potential energy in their existing infrastructure,” says Henning.

“Thinking out of the box is the name of the game, which will ensure a sustainable and affordable supply of water to all consumers in Drakenstein.”

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INFRASTRUCTURE NEWS

FROM AROUND THE CONTINENT

ETHIOPIA Tangible energy and infrastructure solutions

AFRICA Bringing rail to the continent The African Export-Import Bank (Afreximbank) and Thelo DB have signed a memorandum of understanding (MoU) that will give both parties an opportunity to develop, finance and operate railway projects across Africa.

The pair have agreed to collaborate to modernise the continent’s railways, thereby promoting trade, investment, and economic and skills development. Both see the urgent need for efficient and effective transportation and logistics on the continent, particularly in the freight railway sector.

African governments have long been discussing the importance of the regional integration of infrastructure projects as one of the ways to both free and speed up the movement of goods in order to stimulate intra-African trade.

Professor Benedict Oramah, president, Afreximbank, affirmed the two companies’ commitment to supporting trade on the continent. “That includes creating capacity to deliver to the markets. With Thelo DB’s capacity to deliver and operate railway mobility systems, and Afreximbank’s ability to finance projects, we have an incredibly strong team,” he says.

Thelo DB is looking at projects in Southern, East and West Africa, which the company believes are home to corridors that transcend country borders.

The MoU is part of the realisation that the African Continental Free Trade Agreement will face challenges without the logistical capacity to move goods.

“The MoU solves a very important part of the puzzle for us, which is, when we’re doing these big capital projects, how do we finance them? Rather than building our own expertise as Thelo DB, working in an integrated manner with Afreximbank magically gives us a solution to that challenge. So, we can now sit down with our clients and say not only do we bring technical capacity of a global standard, we bring you unbelievable capital mobilisation in the MoU we signed,” says Ronald Ntuli, chairman, Thelo Group.

10

IMIESA January 2020

Earlier this year, Siemens signed a memorandum of understanding (MoU) with the Investment Commission of Ethiopia to address the country’s energy and infrastructure sector challenges, to assist the government, stabilise and expand the existing grid infrastructure, and explore island solutions for industrial hubs/parks and microgrid solutions for remote villages.

The Ethiopian government’s Growth and Transformational Plan II has a goal to achieve universal electricity by 2025.

Currently, 56% of the Ethiopian population does not have access to electricity. In line with this plan, Siemens will install a solar-hybrid plant in Sodo supplying reliable, sustainable and affordable electricity to the FruitBox Farm, as well as to the surrounding communities.

“The FruitBox Farm project is a key Siemens lighthouse project aimed at demonstrating the importance of corporates aligning to a national vision that will ultimately benefit the lives of people in different societies,” says Sabine Dall’Omo, CEO, Siemens Southern and Eastern Africa. “Government plans supported by business initiatives are essential and play a crucial role in moving economies forward and ensuring economic prosperity for all,” she adds.

Apart from providing electricity to the FruitBox, the project will provide electricity to a nearby school, which has approximately 300 students, as well as 150 households, impacting roughly 1 500 people.

The project goes beyond rural electrification by creating 200 direct new jobs, even in challenging environments. Through this initiative, students from surrounding areas will be trained on how to operate and maintain the microgrid and integrate the agricultural value chain through oil and juice production.

GHANA Agreement signed for high-speed railway

SOUTH SUDAN Electricity to spur development The government of South Sudan recently commissioned a US$38 million (R554 million) upgraded power distribution system financed by the African Development Bank (AfDB) to restore reliable electricity supply to Juba’s CBD and boost suburban livelihoods.

The Juba Power Distribution System Rehabilitation and Expansion Project is the first in a series of major energy sector interventions by the AfDB to improve livelihoods and build resilience in South Sudan. The project aims to scale up electricity access and use in South Sudan’s rapidly growing urban communities, and to stimulate economic activity and boost incomes.

Inaugurating the upgraded facility, President Salva Kiir said, “This project will spur development in the countr y, where more than 70% of lighting relies on generators and others on kerosene.”

On completion, the upgraded power distribution system will consist of a 145 km, 33 kV medium-voltage distribution line and a 250 km low-voltage distribution line with 145 new transformers installed. At least 20 000 domestic and commercial consumers will be connected.

The government is focused on developing its hydro and renewable energy resources, with an aim to generate 10 MW to 40 MW of renewable energy. The government also plans to invest in a 1 080 MW Grand Fula hydropower project to generate and distribute power across various states in South Sudan.

The African Development Bank (AfDB) has thrown its weight behind a concession agreement for the construction of a high-speed railway in Accra, Ghana’s capital.

The Accra Skytrain project, representing an investment of US$2.6 billion (R37.9 billion), is a highcapacity public transport system that is completely automated and cost-efficient, using pneumatic propulsion technology. The system will transport more than 380 000 passengers annually and create some 5 000 jobs during its implementation phase.

“This is what Africa wants: finalised agreements,” says Akinwumi Adesina, president, AfDB Group.

“What we want is for Africa to invest in Africa. We want to see this kind of thing happening all the time.

This project will modernise Ghana, providing green transport for its citizens.”

Solomon Assamoah, fund manager for infrastructure investment, believes that this project will profoundly transform Ghana’s economic capital. “This is a major contribution to infrastructure development in Ghana, and in Africa as a whole. We need mass transport. This project will help overcome traffic gridlock,” he explains.

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GEOTECHNICAL ENGINEERING

The DIP advantage Driven ductile iron piling (DIP) is a simpler, faster and safer method of installing piles compared to other conventional techniques.

D

evised in Europe around 35 years ago, DIP is a wellproven technology. The ductile iron material was originally developed for large-diameter water and sewer pipe lining projects. The same principle led to the fabrication of high-strength pipes for driven piling systems.

Recognising the advantages of DIP for the local market, GeoGroup company Geopile Africa introduced the technology to South Africa in 2012. Since then, Geopile has completed more than 50 DIP projects, ranging from bridge to building construction installations.

The DIP approach is especially well suited for challenging ground conditions with limited

Lift shaft piles, fitted with Y32 full-length rebar

geotechnical information. The penetration rate of each pile is recorded per metre. In the case of end-bearing piles, they are driven to practical refusal, with the final penetration ‘set’ dictating when the pile is complete.

“Continuous flight auger piles and driven cast in situ concrete piles tend to refuse where boulder/cobble obstructions occur,” explains Warwick Nel, New Business and Project Manager, Geopile Africa. “In other words, they often fail to penetrate through to reach suitable founding material.

“The only traditional method that can compete with DIP in this geology is percussion drilling. However, the latter option is very expensive, requiring a specialised drilling head and the insertion of a casing to cast the pile. DIP is, therefore, the most competitive approach,” he continues.

Trial installation The point is well illustrated by a recent Geopile Africa project in Stellenbosch, Western Cape.

Here, the geology included the presence of a 2 m to 3 m boulder layer interspersed in a loose sandy clay matrix. Individual oblong-shaped boulders were up to 800 mm in width and length.

Faced with these challenges, the client’s professional team had recommended a deep

12

IMIESA January 2020

Geopile rig in action installing DIPs

raft foundation. However, shortly before the commencement date for construction, Geopile Africa was invited to carry out a trial installation to argue the case for a DIP design.

“This provided the perfect opportunity to prove that we could drive our DIPs through the boulder layer to reach bedrock,” Nel explains. The trial was carried out free of charge and Geopile was subsequently awarded the project. The DIP solution cost around R1 million less than the raft foundation option for the Stellenbosch project and was faster by approximately two months.

Before test piling commenced, two rotary cored boreholes were drilled by Geomechanics, a GeoGroup sister company, to verify the depth to bedrock. Geopile Africa then proceeded with the installation of three DIP piles, which all comfortably penetrated the boulder layer.

These piles were installed using a 30 tonne hydraulic excavator fitted with a purposedesigned demolition hammer specified by the DIP manufacturer. This hammer achieves an output of approximately 280 tonnes per blow at up to 400 blows per minute.

“We reached refusal in medium-hard sandstone bedrock at between 6 m and 11 m from platform level,” says Nel.

Construction phase For the actual project, a combination of 118 mm and 170 mm diameter DIPs were

GEOTECHNICAL ENGINEERING

used, installed open-ended and/or with driving shoes. The latter keeps the pipe free of debris, ensuring a 100% concrete fill.

“Open-ended piles were used in lift and stair shafts where resistance to shear meant that the piles needed to carry some tension,” he expands.

The open-ended piles, socketed into the medium-hard sandstone bedrock, provided tensile resistance from skin friction on both the inside and outside of the pile. These piles were reinforced with a centrally located Y32 bar with an ‘L’ protruding 500 mm (or to the underside of the pile cap reinforcing cage).

Piles with driving shoes were installed for compressive column loads. They were filled with 30 MPa concrete, thus providing 5% more load carrying capacity. Compression piles were fitted with a Y16 rebar to centrally place the load plate: 200 mm x 200 mm x 30 mm for 118 mm/7.5 mm piles (550 kN SLS) and 250 mm x 250 mm x 40 mm for 170 mm/9 mm piles (990 kN SLS).

Low-cost housing development Other Geopile Africa DIP projects currently

Observation of the set penetration rate achieved

under way include a low-cost housing development in Cape Town. This development entails the construction of a three-storey apartment building that will tie into an existing one.

The current building rests on a raft foundation, while the new one will be supported by a DIP installation. As with the Stellenbosch project, DIP proved to be the most costeffective approach.

30 years delivering Geotechnical Services in Africa

The Group employs over 200 people and has over 50 drill rigs in operation.

A long term strategy of continual staff development and upgrading of equipment has ensured longevity of the group.

The GeoGroup of companies is an industry leader in delivering the following services to Africa:

• Geotechnical investigations • CPTU & in-situ testing • Exploration drilling • Sonic drilling • Water boreholes • Geophysical/geotechnical Instrumentation • Driven ductile iron pile solutions

0861 436 632

+27 (0)86 663 3896

info@geogroup.co.za

Franki Africa provides dedicated expertise in: • • • • • • •

Piled Foundations Lateral Support Ground Improvement Near Shore Marine Works Design – Build Foundation Repair & Underpinning Liquefaction Mitigation

As part of the connected companies of Keller, Franki Africa offers a comprehensive range of geotechnical and marine engineering services including both design and construction for the General Construction, Civil Engineering and Mining Industries. Call Franki today about your next project.

+27 11 531 2700 | franki.co.za | info@franki.com

GEOTECHNICAL ENGINEERING

Definitive geotechnical work unveils bumper edition Reflecting the rich history of the Franki legend, the Fifth Edition of the widely acknowledged ‘Blue Book’ on geotechnical engineering incorporates elements of its holding company, the Keller Group, and many of Keller’s state-of-theart ground improvement and grouting technologies.

T

he book, entitled A Guide to Practical Geotechnical Engineering in Africa, was officially launched by Keller’s Professor Michal Topolnicki, senior technical advisor, at the 17th African Regional Geotechnical Conference in Cape Town, held between 7 and 9 October 2019. The conference was attended by both local and international delegates, including senior board members of the ISSMGE.

A celebrated tradition This latest edition maintains the 50-year tradition of updating this now well-established textbook every 10 years. The book also mirrors the evolution and changes within Franki, from a small piling company in the era after the Second World War to the leading geotechnical engineering company in the African region.

The first two editions, published in 1976 and 1986, respectively, entitled A guide to piling and foundation systems, illustrate Franki as a piling company and the Southern African branch of the worldwide Belgian-owned Franki group. Franki started as a small piling company in Southern Africa after the Second World War and expanded into a significant piling company during the 1950s and 1960s.

Co-authors Dr Nicol Chang (right) and Gavin Byrne at Franki’s Diamond Sponsor stand at the 17th African Regional Geotechnical Conference

The First Edition was authored by then managing director Ian Braatvedt, with a foreword by the legendary Professor JE Jennings.

The second two editions, published in 1996 and 2008, respectively, are both titled A Practical Guide to Geotechnical Engineering in Southern Africa. They demonstrate Franki’s change of logo and ownership, as well as the evolution into a geotechnical contracting company offering a wide range of geotechnical products, and marine engineering capability.

The development of Franki’s in-house geotechnical design capability is demonstrated by the significant sections on design and the coauthoring of Gavin Byrne as a senior member of the Franki team, for both these editions.

Final cover section Sept2019 vector.indd All Pages

New chapters The new Fifth Edition, co-authored once again

by Gavin Byrne – together with Dr Nicol Chang as technical director of Franki and Dr Venu Raju as the Keller Group’s director: Engineering and Operations – depicts Franki’s expansion through the African continent and the Indian Ocean Islands.

The ownership of Franki Africa by the Keller Group, the largest geotechnical contractor worldwide, is reflected in the significant change and evolution of the book’s content, the inclusion of colour into the graphics and illustrations, as well as the doubling of the pagination from 270 pages in the First Edition to 540 pages in this Fifth Edition.

First Edition, 1976

Second Edition, 1986

2019/09/08 13:48

The cover design for the Fifth Edition.

Franki, as a member of the Keller Group, provides a wide range of geotechnical engineering design and construction services

The new edition incorporates the deep foundation, lateral support, design, marine and limited ground improvement content of the Third and Fourth editions, and adds Keller’s extensive range of ground improvement, grouting and associated design methodologies.

Trenchless technology and the introduction to Limit State Design are an added feature of the comprehensive publication. Franki’s key suppliers are acknowledged and provided with advertorial space and reference to their products/equipment.

The foreword by Professor Peter Day, recognised internationally for his delivery of the Terzaghi Oration as a leading geopractitioner of the African region, is greatly appreciated for its recognition of the contribution of the ‘Blue Book’ to the geotechnical industry. The authors would like to thank all in the Keller Group and Franki for their contributions and support in the preparation of their new publication.

Third Edition, 1995

Fourth Edition, 2008

IMIESA January 2020

15

INFORMATION TECHNOLOGY

Preventing ransomware attacks Ransomware is targeting government departments.

Simeon Tassev* explores what can be done to stop it.

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he City of Johannesburg recently became the latest victim of high-profile ransomware attacks targeting government departments. This follows on from the City Power attack in July, which encrypted databases, applications and networks, and resulted in users being unable to purchase electricity units for prepaid meters.

Ransomware attacks targeting the public sector have become a trend, not only in South Africa but across the globe. In order for the public sector to ensure that it can protect itself from future attacks, it needs to reconsider security protocols and practices to make itself less of a target and prevent repeated attacks.

Why are governments being attacked?

The simple answer: because they are seen as ideal organisations to target. Cybercrime is all about the money, and the public sector is potentially highly lucrative. Despite its name, ransomware is often not only about holding data to ransom; there is typically a time bomb attached that will destroy the data if the ransom is not paid.

Governments provide critical services and are in possession of large volumes of data that

they cannot afford to lose or have exposed.

Recovery is often difficult and costly – so much so that the ransom demands are seen as the lesser of two evils, so a successful attack is more likely to yield profitable results.

These attacks are not limited to South Africa, nor are they a new occurrence. The attack on the National Health Service (NHS) in the UK in 2017 seems to have ushered in an era where threats of this nature are a frequent occurrence across the globe. In fact, an article in the New York Times stated, “More than 40 municipalities have been the victims of cyberattacks this year”. The article also states that 22 cities across Texas were simultaneously held hostage for millions of dollars after an attack infiltrated their computer systems and encrypted their data.

Invest in security Attacks on public sector organisations are on the rise, and ignoring the threat is no longer an option. Once a successful attack has been perpetrated, it is highly likely that hackers will attempt the same tactic again because it is a low-risk strategy with high potential reward. The only solution is to invest in security to close loopholes and potential vulnerabilities.

Often, cyber attackers gain entry as a result of human error, most commonly by an employee clicking on an infected link or attachment.

Consequently, stricter controls need to be put into place and greater effort placed on education and security awareness. Data itself needs to be protected via encryption to make it more difficult to steal, or to use once stolen.

Effective backup and recovery solutions also need to be in place, along with best practice security processes, tools and maintenance.

All systems must be kept up to date with the latest patches, updates and definitions.

Once an attack occurs, a post-mortem analysis is a critical step in understanding how the incident occurred and what vulnerabilities exist and need to be addressed. This is the only way to work towards preventing another attack. While every attack is different and its anatomy and methods may change, it is essential to ensure that the same attack strategy cannot be used again.

Ultimately, data is the target in ransomware attacks. It is imperative to understand what data exists, where it is stored, what it is used for and what the impact is if it is stolen or compromised. If data is not being effectively managed, then a breach will likely send any organisation into a tailspin, as it scrambles to understand what data has been affected and what the impact is.

Prevention is definitely better than the cure. *Simeon Tassev is the managing director at Galix.

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IMIESA January 2020

MUNICIPAL FOCUS | NELSON MANDELA BAY

Nelson Mandela Bay heading for Day Zero?

Nelson Mandela Bay is moving to have itself declared a drought disaster area, as water in the metro’s largest supply dam has dropped below abstraction levels.

D

uring late 2019, Nelson Mandela Bay Municipality advised residents to reduce water consumption to 50 litres per person per day. This call came as water abstraction at the Impofu Dam – the metro’s largest supply dam – was halted due to prevailing drought conditions, and the municipality’s combined capacity of major supply dams dropped below 34%.

This despite rain in November resulting in the Churchill Dam over flowing; however, former mayor of Nelson Mandela Bay Mongameli Bobani noted that Churchill Dam is only a third of the size of Impofu Dam, and the rain had no significant increase in the average dam levels.

Trouble at Impofu During a visit to the Impofu Dam, Barr y Martin, senior director: Water and Sanitation, Nelson Mandela Bay Municipality, noted that the lowest intake point of the dam is now above the water level of the dam, requiring abstraction of water at the dam to stop.

“Approximately 100 mm rain was measured in Kareedouw during recent rain, but it did not result in any significant inflow in Impofu as yet,” he said. The Impofu and Churchill dams are both located on the Kromme River, allowing for the possibility for Churchill Dam to overflow and fill Impofu Dam. Although Impofu Dam has dropped below abstraction levels, Martin said the municipality hopes to still abstract some of the remaining water.

“This Impofu Dam is currently at 16% and we might still be able to drop the level to 9%, as we hope to float a barge on the dam with pumps fitted on it. We will then pump water from the dam into the inlets of the tower to distribute it to our consumers,” he explained.

“The most critical issue is that we must cut back on water consumption. We found that too many people use more than 1 000 litres of water a day. In a drought situation, it is criminal. We need to stick to 50 litres per person per day.”

Drought declaration Andile Lungisa, MMC for Infrastructure,

Engineering, Electricity and Energy, Nelson Mandela Bay Municipality, said the necessary steps were being put in place to implement a drought declaration.

“Work is now being put into place to ensure that the necessary interventions are put in place to manage our water with a greater emphasis on conservation and the reporting of leaks.

“Water is a precious natural resource to which our residents have a constitutional right, which means we are reliant on sufficient rainfall to deliver on this priceless source for our constituencies,” said Lungisa.

The metro has been experiencing a dry period of below-average monthly rainfall since November 2015, resulting in declining dam levels and water storage capacities.

In September 2018, good rains occurred in very specific catchments and the average dam levels increased from 17.82% to 53.03%. This rainfall created a false sense of security as certain catchment areas did not receive significant rainfall and average dam levels have since continued to drop.

IMIESA January 2020

17

PIPES, PUMPS & VALVES

Demand grows for plastic pipes Despite a struggling economy, the Southern African Plastic Pipe Manufacturers Association (SAPPMA) has reported a steady growth in membership and influence over the past year, says CEO Jan Venter.

S

peaking at the Association’s 15th Annual General Meeting, Venter said the importance of having a dedicated, non-profit organisation that offers technical support and coordinates activities in the plastic piping industry cannot be over-emphasised.

“Judging by the growth in the market and new applications we’ve seen in recent years, it’s clear that plastic is no longer seen as an ‘alternative’ pipe material,” he pointed out.

“It has grown to a dominant position in piping systems worldwide, with an estimated share of more than 50%. In South Africa alone, around 150 000 tonnes of plastic pipe (PVC and HDPE) are produced annually and used across a wide spectrum of industries, including mining, civil, irrigation, industrial, telecommunication and building.”

Plastic piping systems are relied upon to provide integral, long-term and extremely important infrastructure to the country – including sewerage, telecommunication, gas and electricity supply. Moreover, South Africa is rapidly becoming an arid country where water is a scarce resource.

“With increasing demand and inconsistent rainfall, we can no longer afford the huge losses in pipelines (estimated to be in the

18

IMIESA January 2020

order of 40%). We need piping systems that are reliable, leak-free and durable. HDPE and PVC pipes answer this call with distinction, as they won’t rust or corrode over time. They are more cost-effective in applications where soil is aggressive, offer extended lifetimes of up to 100 years and are highly suitable for the rehabilitation of old pipelines,” Venter said.

Growing need for an independent standards body SAPPMA was formed 16 years ago with the purpose of creating absolute customer confidence in the plastic pipe industry and to ensure the long-term sustainability of the industry with top-quality piping systems.

According to Venter, the importance and scope of this task continues to grow each year as the industry develops both in complexity and competitiveness.

“Never before has the need for technical development and maintaining quality been so prevalent. In the past, manufacturers only needed to focus on one standard per product line, and then perhaps only superficially. These days, there are around 124 national standards that they need to satisfy,” Venter explained.

Jan Venter, CEO, SAPPMA

Because SAPPMA’s sole focus is on a relatively small (but crucially important) sector of industry, it is in a unique position to detect and address problems much earlier than any other organisation. Through closely monitoring the quality of the products its members produce, SAPPMA ensures full adherence to all relevant national standards.

Only pipes that are independently tested

and audited are allowed to bear the SAPPMA logo.

Technical marketing and problem-solving SAPPMA also fulfils an indispensable need in the marketplace for technical marketing and problem-solving.

“We have become a repository of technical information and are frequently called upon by municipalities, engineers and decisionmakers to assist with scoping a project, specifying standards or making technical decisions,” Venter continued.

For this reason, SAPPMA has appointed a technical manager to assist with queries and offer professional advice, while the association’s technical manual for PVC and HDPE piping systems (regularly updated and distributed) continues to be indispensable to designers and decision-makers in the piping business.

During 2019, SAPPMA hosted regular workshops for both members and nonmembers alike focusing on different aspects of quality. SAPPMA will again be hosting similar sessions in main centres during 2020.

Factory audits Factory audits will continue to be a key factor in the success of the association and are seen as an important differentiator that sets members apart from non-members.

Announced and unannounced audits were completed on all manufacturing and installing

In South Africa, around 150 000 tonnes of plastic pipe (PVC and HDPE) are produced annually and used across a wide spectrum of industries

members during 2019 and SAPPMA has reported an increase in quality awareness and compliance.

New SAPPMA board and recognising contributions SAPPMA announced the names of its new board of directors who will be responsible for leading the association in the next financial year. Jan Venter will remain chairman and CEO, assisted and supported by Terence Hobson (Sun Ace SA), Don Coleman (Sizabantu Piping Systems), Renier Viljoen (Rare Plastics), Mark Berry (Safripol), Trevor Woolward (Pipe-Tech Manufacturing), and Lizl du Preez (PipeFlo).

Alaster Goyns (Pipes CC), Lesley Geyser (Rare Plastics) and George Diliyannis (Safripol) received SAPPMA Merit Awards for 2019. This an annual award that was instituted in 2008 with the aim of recognising and rewarding the input and effort of individual SAPPMA members.

Looking ahead “We are excited about the opportunities that await us in the year ahead, but also mindful of the challenges our members are facing,” said Venter. “I once again urge them not to lose their long-term view, particularly in terms of quality, and not be tempted to take shortcuts that will later come back at a cost.

“Difficult conditions always provide new challenges. It also reinforces the need for a central organisation such as this.

Together, we are making a difference!”

Venter concluded.

Treat your water-energy like gold Unmet efficiency with up to 10%-20% energy cost reduction Super high flow rate Designed for superior cavitation resistance High regulation capabilities

+27 (0)11 383 4000 www.macsteel.co.za

20

IMIESA January 2020

ROADS & ASPHALT PIPES, PUMPS TECHNOLOGY & VALVES

Fight losses with pressure reduction South Africa loses millions of litres of water every year due to pipe leaks and bursts.

IMIESA speaks to Rowan Blomquist, CEO, Macsteel Fluid Control, pressure from 80 bar to repeatedly 13 bar in one of South about addressing faced the threat Africa’s deepest vertical mines. water losses.

What is the first step to consider when addressing water losses?

RB Pressure management is one of the most important interventions to consider when attempting to drive down water losses. The common factor in every water system is the fact that leakage is driven by pressure. Reduce the pressure, even for a short period, and you reduce leakage.

Possibly one of the simplest solutions in this regard is the use of pressure-reducing valves (PRVs). These offer a way to easily and cost-effectively control the maximum pressure entering a zone. As the local supplier for Bermad products, Macsteel Fluid Control offers a range of PRVs that can help utilities to protect their water supply.

Can you provide examples of how PRVs have successfully reduced water losses?

Bermad recently worked with Monterrey, one of the largest cities in Mexico, to install PRVs at strategic points in the system to manage the pressure. Having experienced significant growth over the past 50 to 60 years, the city

of insufficient water supply.

Bermad recommended the 7PM Flow Compensated PRV – a hydraulically operated, diaphragm-actuated water PRV that automatically optimises downstream pressure according to the water demand.

A total of 16 of these were installed over a period of six months. The average pressures have since fallen from 7 bar to 8 bar to between 1.7 bar and 2.9 bar, and the minimum flow range reduced by 50%, while the maximum flow was reduced by 15%.

The city experiences fewer pipe bursts and has secured significant financial and water savings.

Another example is the installation of a multistage pressure-reduction system to reduce

Rowan Blomquist, CEO, Macsteel Fluid Control

The mine was experiencing regular pipe bursts as a result of the PRV system failing or overshooting.

Bermad and Macsteel Fluid Control were able to develop a solution using our WW-8”-82055-Y-S-ISO-40-EB-NN-FVIU valve.

The new system uses a PN 100 PRV slave to reduce pressure from 80 bar to 30 bar, as well as an 800-series singlechamber valve to further reduce the pressure from 30 bar to 13 bar.

The new system has successfully resolved the mine’s water pressure challenges, significantly reducing maintenance costs and increasing the mine’s uptime.

Why is pressure management important in the South African context?

Considering South Africa loses an estimated 37% of its potable water through leaks – representing approximately R7 billion in potential revenue – it is clear that PRVs have significant potential to secure water savings in South Africa.

How is Macsteel Fluid Control supporting the local economy?

After supplying a number of well-known products for over 40 years, Macsteel

Fluid Control is now manufacturing quality Bermad products locally.

In line with government’s drive to boost local production, Macsteel Fluid Control has worked closely with Bermad to fine-tune the local casting and assembly of Bermad control and air valves to the necessary standards. The locally cast product will be identical to the imported product in terms of quality and performance.

In this way, we can offer a wide range of quality PRVs, providing costeffective solutions for any pressure management issue while supporting the local economy.

IMIESA January 2020

21

ROADS & BRIDGES | CAPSA

Rising above the floods The positive impact that infrastructure investments have on rural communities is well illustrated by the Ga-Ntata project in Limpopo.

The condition of the low-level Molotsi River Bridge prior to its demolition: severe damage had been caused due to flooding and poor founding conditions

Motlatswi River: the existing low-level bridge was completely damaged and had settled

The completed high-level bridge across the Motlwatsi River

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IMIESA January 2020

ROADS & BRIDGES | CAPSA

Placement of the precast deck panels and construction of the bridge decks

Construction in progress on the new Molototsi Bridge, with the old one in the foreground

pile caps, piers, abutment walls and bridge decks were constructed using ‘W’ durability specification concrete.

The diaphragm beams were designed to be pre-stressed and were manufactured as precast concrete elements. Beams were delivered to site by trucks and launched to the tops of the piers and abutments by cranes. A total of 84 beams were installed to form the bridges. The 250 mm thick decks were cast in sections.

Greenfield route

T

he village of Ga-Ntata is situated between the Motlatswi and Molototsi rivers, with access previously provided via low-level bridges. When these were extensively damaged by major floods occurring between 2000 and 2005, they subsequently became impassible during similar extreme weather events. An urgent inter vention was needed to restore the community’s access and mobility.

In response, two new high-level standard river bridges were constructed and have since ser ved as a catalyst for socioeconomic growth within Ga-Ntata, located in the Greater Letaba Local Municipality, approximately 135 km nor th-east of Polokwane.

Nyeleti Consulting was appointed by Roads Agency Limpopo for the planning, design and construction super vision of the new bridges. Construction commenced in October 2015 and was completed in May 2018.

The two existing low-level bridges crossing the Motlatswi and Molototsi rivers, respectively, were demolished to make way for the new structures. These comprise the Molototsi Bridge, which has a 100 m long span and is 13.52 m wide, and the Motlatswi Bridge, with its 60.75 m long span and 13.52 m width. These new bridges are now part of the north-south

corridor link between the R81 (Giyani road) and D3180 (Modjadjiskloof road).

Precast elements Designed to accommodate 6 m scour, the Molototsi Bridge crossing consists of a four-span, simply suppor ted, precast beam-type deck with reinforced concrete wall-type piers and abutments founded on 900 mm oscillator piles (12 m deep).

Each deck span consists of twelve M10 precast beams with a top slab cast in situ. Ancillar y bridge elements include new Sanral standard F-type parapets.

Additionally, all deck expansion joints are asphaltic plug-type joints.

Aside from having just three spans, all the design and construction elements featured on the Molototsi Bridge are common to the new Motlwatsi River crossing. In both instances, for example,

The scope also included the realignment and upgrading of the existing 3.25 km gravel access road to sur faced standard.

The horizontal geometrical alignment was completely realigned due to the encroachment of the Ga-Ntata village on the existing road reser ve. A bypass road alignment design with dedicated access to the village was adopted and implemented.

The new road, which crosses over both bridges, followed a greenfield approach for more than 90% of its length. The geotechnical investigation showed that the in situ soils exhibited pinhole characteristics and had the potential for soil collapsibility. Due to the low in situ density and stiffness of the material, impact compaction was applied to improve its properties. This also resulted in a more cost-effective pavement design structure.

“In the end, the project turned out to be a huge success for all stakeholders and demonstrates how value engineering approaches and teamwork can create world-class infrastructure even in the remotest rural areas,” concludes Pine Pienaar, CEO, Nyeleti Consulting.

The new road followed a greenfield approach for more than 90% of its length

IMIESA January 2020

23

ROADS & BRIDGES | CAPSA

Designing with statistical certainty Ensuring repeatable quality hinges on accurate laboratory and field data, which requires a systematic approach that can be statistically proven and validated.

S

howcasing excellence, the Conference on Asphalt Pavements for Southern Africa (CAPSA) celebrated its 50th anniversar y in 2019 and brought together local and international experts.

These included Ané Cromhout, a JG Afrika pavement engineer, who presented an insightful paper, titled ‘The Impact of probability density function (PDFn) on indicators relating to pavement per formance for flexible pavement structures’. The paper was co-authored by Paul Olivier, managing director of JG Afrika, together with JG Afrika pavement specialist Dr Emile Horak.

PDFns are used to describe the probability distribution of a continuous random variable and are an invaluable tool for optimum road design, quality control, and durability.

“PDFns minimise the ‘data-cleaning’ process by removing outliers to efficiently detect localised pavement structural weak spots that would other wise have been hidden due to the law of averages,” explained Cromhout. “Application of the analysis process using PDFns is nearly limitless, enabling engineers to make better judgement calls and apply critical thinking to the way in which data is handled.”

Cromhout cited a runway pavement project where JG Afrika used PDFns to significantly improve the quantification of deterioration across the pavement mat, or width. PDFns were employed to monitor change over time in material stress response. In turn, deflection bowl parameter analyses were used to identify areas in the pavement structure that were relatively weak.

Ané Cromhout, The runway was a JG Afrika sur veyed using a falling pavement engineer, presenting at weight deflectometer CAPSA (FWD) along the centreline and at of f-sets of 5 m, 10 m and 15 m, to the right and left of the

centreline. Subgrade PDFns demonstrated an innovative comparison over the width of the pavement. During construction, shapes of the PDFn were used to gauge good quality standards.

Cromhout explained how the development of the PDFns started as “a dire need to track the trend of pavement materials and their subsequent weakening over time.” In projects relating to per formance monitoring (pavement management systems), FWD data is readily available over longer monitoring timeframes.

“By comparing apples with apples, the PDFn cur ves show whether a pavement is failing at a faster rate than designed and creates an opportunity to timeously inter vene to extend the life of the structure,” she explained. “Ever ything that fails over time due to fatigue will not have a typical normal distribution, but rather a lognormal distribution. This fur ther complicates matters when giving feedback on the 90th percentiles.

“Numerical iteration is used to obtain the exact percentiles for distribution cur ves that do not follow Gaussian normal distributions. The thought was to let the data lead the design engineer to the distribution type that best models the data, and not merely assume a hypothesis and misuse data to ‘prove’ predetermined biases,” she continued.

Thin asphalt surfacing At CAPSA 2019, Horak also presented a paper, titled ‘A paradigm shift on permeability of thin asphalt sur facing’.

“Typically, the PDFn of density and voids in the mix (VIM) have been shown to follow the normally distrubuted bellshaped cur ve,” said Horak, summarising key points. “The average and mean values

ROADS & BRIDGES | CAPSA

may be inside the density or voids range specifications. However, there may be values beyond the known precipice of density and voids, which is noteworthy considering that experience shows that asphalt sur facing fails due to the outliers and not, as previously thought, the values of the averages.

“Statistical procedures should, therefore, be re-examined to reflect the PDFns of as-built results to provide a better appreciation of variability outside the specified ranges,” he continued.

The vacuum sealed (VS) method provides more consistent and accurate results at a higher range of VIM than the older saturated sur face dr y (SSD) method. This is significant, as a rise in voids also implies a high probability that they are interconnected. Horak, therefore, recommended that the VS method be used as standard laborator y procedure when permeability aspects are monitored.

Vertical and horizontal permeability He also noted that various aspects relating to the construction and mix design could contribute significantly towards vertical permeability. Factors such as microcracks due to rolling technique or cold compaction and the continued use of rolled-in-chips (RIC) are now known to be the main facilitators of water intrusion into asphalt layers.

Horizontal permeability in asphalt layers can be between 3 and 10 times higher than vertical permeability. For this reason, asphalt layers often display confusing signs of permeability in areas where the traditional indicators, such as VIM, may not support this.

“Fur thermore, ver tical and horizontal permeability are seldom measured separately in the laborator y,” he

explained. “In South Africa, the field permeameter (Mar vil) is also prone to measurement error.”

He recommended that the prior rendition TG35 specified EN test method, which can measure horizontal as well as vertical permeability, be used for both types of measurements. This is in addition to adjusting the Mar vil test method to measure either ver tical or horizontal permeability by var ying the diameter, while also addressing the repeatability issues resulting from messiness of the Mar vil test itself.

Moreover, Horak noted that asphalt density specifications and statistical quality assurance procedures allowed for lower densities than originally specified.

For example, a minimum of 93% or lower specification implies that VIM is already 7% or higher. This lift-off point is often achieved by default, as 92% compaction is frequently allowed for individual values, and this implies that there are field air voids as high as 8% beyond the precipice. He thus recommended that VIM be measured according to the VS method and the 7% or *5 lift-off values closely monitored during construction.

Horak also suggested that permeability potential be calculated via published correlation relationships with voids and other aggregate packing information.

This should be used as a benchmark to determine permeability potential even before more detailed field or laborator y measurements of permeability are undertaken.

Hot mix He also noted that it had recently become apparent that permeability potential of hot mix asphalt (HMA) could be monitored via binar y aggregate principles that were correlated with Bailey ratios and porosity

calculations from grading and aggregate packing. An improved understanding of the interconnectedness of voids can be established and used in a benchmark-type quality assurance and control approach to determine whether an asphalt layer is prone to high permeability.

“Moreover, the actual indirect benchmarking of permeability can be under taken using international studies based on a wide variety of published information that is linked to packing principles, VIM and pore size of interconnected voids,” he added. “It can discern between highly variable and less variable permeability of HMAs – even if only used to determine the PDFn of the derived permeability.”

Performance-based testing Cromhout also participated in a workshop on the optimal design of asphalt that was held on the last day of CAPSA 2019. It continued the focus of a workshop that was held at CAPSA 2015 to transition South Africa towards per formance-based testing and the finalisation of TRH8.

The new design criteria have already been specified by one local city and in new Sanral contracts, with other client bodies expected to follow suit.

Meanwhile, a Road Pavement Forum task group has also been established for the implementation of Manual 35/TRH 8 and has involved all client bodies in the process.

Notably, Specialised Road Technologies, a JG Afrika sister company, also exhibited its new digital video analysis technology at CAPSA 2019. Developed specifically for Airports Company South Africa, the technology is also being enhanced to create a road-asset register in a geographic information system platform for Bakwena Platinum Toll Concessionaire.

IMIESA January 2020

25

ROADS & BRIDGES | CAPSA

The road funding conundrum

S

At 750 000 km, South Africa’s road network is the 10th largest globally.

This extensive network faces heavy usage and requires significant funding for ongoing maintenance and repairs.

By Danielle Petterson

outh Africa needs R86 billion to sustain its current road network. To address the identified backlog, a further R30.1 billion is needed. “The total cost requirement is therefore R116 billion and for 2017 we were allocated only R67 billion,” Saied Solomons, CEO, Sabita, told delegates at CAPSA 2019.

The fuel levy ser ves as one of the main methods of collecting funds for road construction and maintenance; however, there would need to be substantial increases in this levy for it to cover the real costs. “To reach the R116 billion we need, we would need a R2.85 increase in the levy per annum, and that will never happen – politically, socially, economically, it cannot be done,” said Solomons. In fact, he argued that the efficiency of the fuel levy is decreasing year on year.

More concerning still is that older vehicles have higher fuel consumptions and are generally owned by poorer individuals. “Those that are less well-off are paying more to travel the same distance on the road. That’s one of the inequities of the current fuel levy mechanism,” said Solomons.

With this in mind, it is important to consider the various mechanisms available to collect road funding.

Common funding models “Politicians and road management professionals have been grappling for decades over how to secure adequate funding for

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IMIESA January 2020

the operation and maintenance of their countries’ road systems, without alienating the ver y road users whose journeys they are tr ying to improve,” said Don Smith, senior technical director, IMC Worldwide.

However, he stressed, “There is rarely, if ever, one single solution to the problems facing road funding decision-makers. It’s a real conundrum. Ever y countr y faces a slightly different set of challenges and, for that reason, a carefully worked-out blend of solutions is needed in ever y case. And for any given countr y, the ideal solution changes from time to time as well.”

Globally, there are three common road funding models in place: 1. General taxation General taxation is used in most countries.

Revenue is collected from the general population via taxes and duties, and paid into a central fund before being allocated through the annual budgeting process.

However, this is closely linked to the health of the economy and the effectiveness of the taxation system.

2. Dedicated road funds Several dedicated road funds were set up in the 1980s, 1990s and early 2000s, in response to some countries’ problems with raising money for road networks.

According to Smith, the World Bank was a major promoter of this, as were other major development finance institutions seeking to protect their investments into road infrastructure.

The principle is that the road users generate most of the revenue. It requires the central government to draw up special legislation that establishes a road fund as a separate entity and a dedicated fund. The road user charges are made up of existing taxation elements paid by road users, which are ring-fenced within the fund.

“This requires the central government to let go of a certain amount of control over a big percentage of its income, and I think this is one of the problems that comes with setting up a dedicated road fund. Many central governments still find it ver y hard to let go in practice,” said Smith.

ROADS & BRIDGES | CAPSA

TABLE 1 Extracts from 2019 Estimates of National Expenditure, Vote 35 (in ZAR)

2012/13 9 728 055

2015/16 12 843 488

2014/15 11 916 947

2012/13

2013/14

Provincial Road Maintenance Grant – supplementary funding to provinces Medium-term expenditure 2014/15 2015/16 2016/17 2017/18 2018/19 2019/20 2020/21 2021/22

7 981 845

8 737 775

9 361 498

9 531 744

A ‘pay-as-you-use’ model is also problematic because rural and access roads have lower traffic volumes. You must, therefore, be realistic about collections and a proxy payment must be set up, such as a fuel levy.

3. Tolling According to Smith, tolling can be a ver y successful way of getting new infrastructure paid for on parts of the strategic road networks. Tolling often operates as a concessionaire and has worked successfully in several countries, including South Africa.

2016/17 2017/18 13 915 586 15 944 823

Medium-term expenditure 2018/19 2019/20 2020/21 2021/22 18 624 158 21 177 224 21 751 034 21 599 001

2013/14 10 497 184

10 478 194 10 753 663

Overcoming funding challenges Agreeing with Solomons, Smith argued that consideration must be given to how to supplement the fuel levy as more efficient engines, hybrid and electric vehicles make a noticeable impact in the funds collected.

Other sources such as vehicle licence fees, per-kilometre charges and congestion charges are all possibilities to supplement income. Where avoidance is possible, such as with open tolling, this must be seriously considered. Tolls are only effective on a limited scope and do not solve the bigger road funding problem, says Smith.

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He points out that many of the problems associated with road funding issues are less technical than institutional. “There are perfectly good solutions, but if the other parts of the jigsaw aren’t in place, they can come unstuck against institutional, social or political resistance that can, in the worst case, render them unworkable,” he stresses. The Gauteng Freeway Improvement Project (GFIP) in South Africa is a perfect example of this.

“We can’t just invent money – we have to work out a better system of making the overall ecosystem work,” he says. There are three options:

ROADS & BRIDGES | CAPSA

1. Increase the level of funding 2.

Do more with less (maximise value for money) 3.

Improve public understanding of the need to pay more.

To achieve the best balance, there must be investment in establishing good systems, programmes, plans, and regulator y structures. Most important, however, is that the money is collected, regardless of the method.

The road funding model is a complex and intricate one, and any change has a knock-on effect. Any of the aforementioned systems can work, so long as the right processes are in place. Importantly, Smith stressed the significance of changing public perception to the point where road users see it as their duty to pay.

A closer look at SA Addressing CAPSA 2019 delegates on behalf of the Department of Transport’s Prasanth Mohan, Solomons noted that non-payment is the Achilles heel of South

Africa. This culture of non-payment takes a ver y short-term view but has an enormous longterm impact.

If users do not pay with cash, they will pay in other ways, such as with time and vehicle usage, as roads become increasingly congested. “The old adage goes, ‘you pay for good roads, whether you have them or not’, so it is better to have them,” said Solomons.

Aside from non-payment, government faces several challenges, including: • planning and approvals • procurement processes and requirements • lack of budgets vs poor progress and expenditure • community access roads and bridges • lack of information (e.g. road condition, traffic data, non-financial data).

“There is no good feedback loop to the Department of Transport or National Treasur y as to how funds were spent

and the results of that spending, which would provide more motivation for the funds to be used properly,” said Solomons.

Nevertheless, he stressed that South Africa does have a steady source of road funding (see Table 1). However, South Africa’s road infrastructure development agenda, especially key strategic projects, will be dependent on the resolutions made around the GFIP.

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WATER & WASTEWATER

Improved rooftop water storage and booster pump system to provide backup and uninterrupted water distribution through the building

Improving water resilience: a private sector perspective The private sector is heavily impacted by the major risk of water security, leading to grave financial consequences. By Hanine van Deventer, Konrad Röhrs and Belinda Herbst

S

ince 2017, the term ‘Day Zero’ has caused great concern to businesses, and raises questions by those dependent on these businesses. The dam levels in the Western Cape have since recovered significantly, leading to relaxed water restrictions, but this does not entirely reassure the private sector of uninterrupted municipal water supply.

Water is a precious commodity that needs to be wisely managed to serve the ever-growing

Belinda Herbst, candidate civil engineer, AECOM SA

population and promote economic growth.

South Africa is a water-scarce country and some projections estimate that we currently exploit roughly 98% of our available water supply resources. In certain respects, the term ‘load-shedding’ will potentially not only be synonymous with the provision of power, but with that of water as well. The ability of all stakeholders to respond wisely, lawfully and fairly in a water crisis becomes a daunting and complex minefield, especially

Hanine van Deventer, senior engineer, AECOM SA

to enterprises not the requirements.

knowledgeable

of

Actions to improve resilience It is important that all municipalities – as water services authorities (WSAs), as custodians of the law, and as water service providers (including sanitation services) – proactively increase their own resilience, and similarly encourage and incentivise their endusers to do the same to cohesively improve

Konrad Röhrs, associate engineer, AECOM SA

IMIESA January 2020

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WATER & WASTEWATER

their response to water crisis conditions as a community.

Various commercial, industrial, retail and government clients approached AECOM SA during the prevailing water stress period brought about by the multiyear drought in the Western Cape, with the projected crisis of large-scale interrupted water supply, to alleviate their reliance on municipal water supply. Their objectives were primarily driven by commercial (loss of income) and liability concerns (safety and insurance requirements). However, idealistic aspirations of reduced long-term utility costs and reduced, or independency of, municipal water supply also played a role.

The influence of time constraints played a significant role. Some clients noticed the looming crisis, requested budget and engaged early. Some were more structured, but many left it too late and were required to respond to all these critical concerns simultaneously to manage the immediate and evident crisis.

The emergency solutions and mitigations encountered were, in some instances, quite innovative, while others were more radical, sometimes inadequate, high risk and beyond the legislative framework. Typical alternative water sources and water saving initiatives considered included, inter alia: •W ater saving initiatives: replacement of conventional sanitar y fittings with water saving technology (in many instances, there was a misconception of what these technologies were and their effectivity), alteration of air-conditioning systems, conversion to dual plumbing water systems and addition of water suppression systems to supplement fire extinguishers.

•W ater sources: rain- and greywater

Plant treating basement drainage sump water to drinking water standard – enough to serve in excess of the building’s complete water demand

har vesting, reclaimed groundwater har vesting (collection of seepage groundwater or borehole water), blackwater and greywater treatment, potable water tanker supply and use of bottled drinking water.

• Other: work from home to reduce business interruption; supplying employees with imported water instead of them having to queue for water during business hours and sparing them the inconvenience.

Challenges When faced with the daunting task of implementing infrastructure to combat an unprecedented event, stakeholders can often over- or, worse, underestimate the level of inter vention required. Needless to say, time was of the essence as Day Zero crept closer, with several aspects to consider, including: • P rivate sector companies are seldom knowledgeable or equipped to deal with water crisis inter ventions on a regular basis, possibly leading to an unwitting and/or hasty approach to implementing solutions.

•W

hen inter ventions first star ted, legislation and guidelines for water resiliency measures for private application were progressively made available on different online forums. However, the general awareness, timeous and correct understanding and interpretation thereof posed a significant challenge to most clients. In cer tain instances, this had the potential to: (1) prevent the correct implementations from taking place from the start; and (2) cost time and resources from the business itself to determine the best course of action for implementing water-resilient inter ventions under limited time, shifting risk parameters with potential long-term legal and cost implications.

• The objectives for business water resiliency inter ventions can differ considerably – from alleviating reliance on municipal supply to an attempt of going off the municipal grid completely, as well as complying with auxiliar y obligations (e.g. tenant agreements, public relations, etc.) to ensure water supply in times of interruption. The type of inter vention can impact significantly on the timeline and cost of the inter ventions.

Conclusions

Water storage tanks to provide two days’ backup and the introduction of alternative water supply

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IMIESA January 2020

While assisting the private sector, AECOM obser ved and identified several challenges that restricted the implementation of water saving measures, be it technically, economically or legislatively.

Water management is not the forte of most private sector businesses that take on water resilience inter ventions. They are thus, in many instances, unfamiliar with related legislation and restrictions.

Emergency situations force people to react without being sufficiently informed, where a lack of guidance could further exacerbate the situation.

WATER & WASTEWATER

Typically, many private entities do not realise the risks associated with sourcing, treating and using alternative water. They do not necessarily understand the legal restrictions, as well as the ongoing operation and maintenance, monitoring and compliance required. Beside the risks, there are capital and operational costs at stake. Facilitated procedures and assisted management of some of these activities can improve water security and benefit stakeholders, notably the City of Cape Town’s Guideline for Installation of Alternative Water Systems, published in Februar y 2019, being a step in the right direction.

Not all inter ventions are equal either – various scenarios trigger different legislative requirements that need to be understood by the private sector, as their water system initiatives bear consequences that could impact authorities’ future strategies and operational procedures. Water resource yields and water quality are not a longterm guarantee. Groundwater drainage sump yield is dependent on groundwater tables. This may also drop to levels with

insufficient or no yield, especially during higher abstraction periods associated with water stress conditions.

During the water crisis, the private sector expected some level of support from the regional and provincial WSAs. However, at the time, formulated plans were in many instances not readily available, and measures were not implemented within a more ideal period of time to assist the private sector. Although the water crisis was experienced in Cape Town, water stress situations can occur anywhere and at any time – making the lessons learnt from the Western Cape drought all the more valuable on a national level.

Recommendations Based on the experiences during the Western Cape drought, the recommendations allude to two major stakeholders: private property owners who wish to become more water resilient, and WSAs who must be proactive in facilitating water resilience initiatives to the end-users they ser ve and assist in managing a vulnerable resource.

Private property owners can become more resilient against water stress conditions by: • reviewing their commercial and insurance obligations in terms of maintaining water supply • r educing their water dependency and consumption • familiarising themselves with the national and provincial legislation, regulations and restrictions in terms of water use and development of alternative water sources and systems • engaging with their local WSA on the local application and management of the national mandates according to local by-laws, restrictions and standards • c onsidering local private-public par tnerships in developing alternative water sources.

Early stakeholder engagement can clarify many uncer tainties and expedite procedures to establish a realistic and viable resilience plan.

WSAs need to consider the following activities: • Water sources: Review the security,

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WATER & WASTEWATER contribution and sensitivity of its water resources respective to drought conditions. This includes pollution control measures (acid mine drainage, wastewater, poorly treated effluent).

• Have a realistic water resiliency plan: Also properly communicate the plan to the public and facilitate transition.

• Infrastructure: Review the ability and readiness of its bulk infrastructure to be able to operate intermittently at reduced flows and/or pressures. Consider contingency plans and inter ventions to reduce or control non-revenue water.

• Legislation: Ensure end-users have ease of access to all legislative regulations that govern and facilitate their water use. Provide guidelines and ensure that authorities’ technical and public leaders have a good understanding to enable them to direct and facilitate queries. Ensure that by-laws are flexible and adequate to facilitate the private sector, and well defined in the case of emergency conditions accommodated for.

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•G overnance and decision-making: Ensure that the responsibilities, delegation of authority and decisionmaking forums in the national, provincial and managerial governance environment operated in are clearly defined and understood in the event of water management, to avoid conflict in attending to water management during water stress periods. The forums should not only be ver tically aligned, but also horizontally aligned to adjacent and related governance and management structures – e.g. environmental, procurement, agriculture and sanitation, among others.

• Communicate and collaborate: Reach out and educate the various end-users in different spheres such as industrial, commercial and retail, government entities and schools. Facilitate stakeholder forums and par tner with the end-users in elevating their water resiliency measures. Use different media to inform the public and end-users; for example, an interactive and informative radio broadcast.

08:58

• Commercial strategy: When the water supply reduces, so does the revenue stream; however, the overheads and maintenance costs could potentially increase. Have a cash flow and commercial strategy for implementation during water restrictions and negotiate and communicate these in advance. Consider options for public-private par tnership opportunities within stakeholder forums.

Provide incentives to bulk water users to increase their resiliency and reduce their dependency on the WSA during water stress times.

The Draft Cape Town Water Strategy, published in Januar y 2019, states: “The future is uncer tain, and the cost of ver y severe restrictions is much higher than the cost of insuring against this likelihood by providing additional water supply capacity.”

This emphasises the impor tance for private and public sectors to work together to achieve mutual success. Lessons learnt from the Cape Town water crisis should further be shared to inform future water resilience planning.

WATER & WASTEWATER

Reuse schemes a win-win for PPPs Proven technologies are providing a strong business case for bulk water reuse; however, to successfully implement reuse schemes, it is important to remove the barriers to public-private partnerships (PPPs).

G

overnment needs to attract private sector funding to meet its water and sanitation infrastructure development requirements. Heavy water consumers can benefit, in turn, from the lower price of recycled water. And yet PPPs in this sector have yet to blossom to their full potential, says Chris Braybrooke, GM: Marketing, Veolia Water Technologies South Africa

Water reuse potential Many industrial companies in South Africa already use recycling technologies to reuse their process water. In minimising their water bill, these companies have been able to optimise production costs, while reducing environmental footprint, to improve business per formance. Braybrooke believes that there is significant scope to upscale such processes in South Africa, with an abundant supply of municipal wastewater and large, concentrated industrial basins with suitable process water demands.

The effectiveness of such a scheme is demonstrated by the Veolia-built and -operated Durban Water Recycling (DWR) Project, which recycles 47.5 MLD of municipal sewage to a near-potable

standard for direct reuse by Sapref and Mondi Paper. These companies benefit from a >60% saving in water tariffs as well as significantly enhanced drought supply security.

The benefits to the city are also immense.

At capacity, the plant reduces the city’s water consumption by 7%; the volume of potable water saved each day can be redistributed to 220 000 households.

Capital investment requirements for future bulk potable water supply infrastructure, as well as for expanding marine outfall pipeline capacity, can also be delayed.

“It has also created a long-term revenue stream from a levy raised on the production of recycled water and reduced the city’s operating costs, with the subsequent reduced cost of water ser vices to Durban’s citizens. And beyond its economic, social and environmental benefits, the DWR Project remains a model of success for PPPs in Africa’s water and sanitation sectors,” says Braybrooke.

A replicable PPP model With greater financial pressure on both industr y and municipalities to do more with less, there is great potential to replicate

such a PPP in many other towns and cities across South Africa. Yet, doing so requires overcoming several barriers, namely: • achieving greater buy-in from government to direct water reuse for industrial consumption • ensuring wastewater treatment plants are equipped with modern, effective technologies • sensitising the public to this long-term water security guarantee • where financing is a challenge, duplicating the DWR PPP, where a consortium of investors provided capital layout with no cost to the city.

“Government has acknowledged that it needs the support of the private sector to meet its infrastructure funding requirements. A proven technology portfolio for water reuse is creating an abundance of potentially economically viable applications,” says Braybrooke.

“At a time when government and business need to optimise their spend, let’s work together to identify the economic opportunities of wastewater reuse relationships between municipalities and industr y across South Africa.

“Wastewater is a resource.”

IMIESA January 2020

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WATER & WASTEWATER

Water is fast becoming the most in-demand natural resource. As the population expands, more water will be needed, and planning at local and national government – in partnership with industry – is required to protect this essential natural resource.

By Herman Smit*

Securing our water resources Herman Smit, managing director, Quality Filtration Systems

G

lobal trends in water reuse and a change in the paradigm of water and waste resource recover y management via decentralised facilities will ensure water security in the future. The fundamental principle of water reuse is using the right water for the right purpose, ever ywhere and all the time. That means aiding and accelerating the natural process of cleaning the water to make it suitable for its intended purpose – from irrigation to industrial uses to drinking.

The South African water crisis is potentially only months away from surpassing the countr y’s energy crisis.

The national water and sanitation depar tments have neglected basic human rights, due to poor planning, lack of maintenance and corruption, syphoning funds that were allocated to national water solutions.

Localise treatment As is the norm in many foreign cities, domestic water recover y returns water back to drinking water standards.

Megaprojects are not required to solve the South African water crisis.

Rather, water solutions lie in smaller, simpler projects that assist with water supply and do not rely on hundreds of kilometres of pipelines transporting water around the countr y.

Advanced technologies provide a smaller footprint, less operator involvement and less dependency on chemicals for water treatment. QFS has brought first-world technologies to South Africa and localised them

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IMIESA January 2020

to be more affordable for South African applications.

Singapore doesn’t have freshwater sources and is a leader in water reuse. The country recovers 100% of its wastewater.

Called NEWater, not ‘recycled’ or ‘reused’ water, the nomenclature helps to change consumer perceptions.

Water recover y, along with desalination, will provide the solutions to augment other water sources. QFS is currently constructing an emergency desalination plant of 1.4 MLD in the Eastern Cape for drinking water, and a recover y plant of 1.5 MLD at a textile mill.

QFS takes domestic wastewater directly back to drinking water with membrane treatment. We have successfully installed more than 40 plants – a combination of desalination, reuse of industrial wastewater, process water and mine water. The worldclass technology we use is proven to produce drinking water to World Health Organization standards.

Rural wastewater facilities compete with many other ser vices on the budgets of local authorities, and are often neglected, suffering insufficient maintenance and incorrect operation.

The wastewater facilities are also under pressure to produce water good enough to release into a natural source.

However, this ‘liability’ can be turned into an income stream using the correct technology to produce safe irrigation or industrial water. *Herman Smit is the managing director of Quality Filtration Systems – herman@qualityfilters.co.za.

SOCIAL LABOUR PLANS L-R: Executive Mayor of Umfolozi Cllr Simangaliso Mgenge – assisted by Bheki Nowele, GM: Communities and Corporate Relations, RBM; Induna Bhekokhwakhe Mthiyane of kwaMbonambi; Induna Themba Sithole of KwaSokhulu; and Deputy Mayor Cllr Simangele Thabethe – cuts a ribbon at the testing centre, while other councillors and stakeholders look on

Giving back to communities The world leader in heavy mineral sands extraction and refining, Richards Bay Minerals (RBM) is committed to making a meaningful contribution by ploughing back millions in infrastructure projects.

W

orking in conjunction with Umfolozi Local Municipality (ULM), RBM recently handed over two buildings – a community service centre and a vehicle testing facility. Combined, the projects are valued at over R32 million. More than 50 work opportunities were created during construction.

The Thusong community centre brings together important government departments, including Social Development, the South African Social Security Agency (SASSA),

The Thusong Service Centre brings together important government departments

Community Safety and Liaison, and the Independent Electoral Commission.

“We believe in ‘beyond mining’ and we want to leave a legacy for future generations to know that RBM puts people before profits,” said Bheki Nowele, GM: Community and Corporate Relations, RBM, speaking during the handingover ceremony.

“We know that in some areas people complain that mining companies do not give back to the community. At RBM, we are working hard to change this perception,” Nowele continued. He added that RBM will work closely with ULM to ensure there is satisfactory service delivery by various government departments.

Cllr Simangaliso Mgenge, executive mayor, ULM, said the new facilities will assist in job creation and to grow the local economy.

“The community centre will allow people to get all the services they need closer to their residences, while the vehicle testing centre will help to ensure the safety of all road users,” he stated.

Werner Duvenhage, managing director, RBM, said the role of infrastructure is critical to the sustainability of local communities, accelerating economic growth and contributing towards poverty alleviation.

“As a respected mining company, we are driven by a sense of purpose and giving back to communities in a manner that empowers individuals. This is important to ensure that generations benefit from our myriad projects,” he explained.

He said RBM’s investment in the community service centre and vehicle testing facility were examples of a range of initiatives aimed at transforming local economies and supporting government’s agenda to promote an inclusive society.

The vehicle testing facility will bring service delivery closer to the people

IMIESA January 2020

35

ENVIRONMENTAL ENGINEERING

Retaining the sea The modular strength of concrete retaining block walls is put to the test as a marine erosion countermeasure.

H

erolds Bay is a small, quaint seaside village situated in the Western Cape, along the Garden Route. It is known for its sheltered location and idyllic beach, which, while tranquil in summer, occasionally comes under attack from the sea in the winter months. During this period, the homes built close to the beach need protection from the waves to prevent flooding and subsequent damage.

The original retaining structures built some years back were

structurally ineffective and frequently damaged during stormy conditions.

This motivated a decision by George Municipality to construct improved beach protection measures. “The municipality wanted a new uniform wall between the beach and the road that would withstand the sea forces, but would also provide an accessible and aesthetic barrier,� says Paul Goedhart, Tuiniqua Consulting Engineers, who conceptualised the new wall. To meet these requirements, a stepped reinforced precast concrete

block wall was designed. The wall was founded on the underlying rock since the level of the beach sand varies due to the wave action. Where feasible, the old wall structure was left in place.

Where the depth of the rock level was impractical for normal excavation, the wall was built on a reinforced concrete strip footing. A reinforcement fabric was used to anchor the wall to the compacted cement-stabilised backfill material behind the wall and enough drainage was provided to reduce hydrostatic pressures. The top

The Terraforce wall protects homes close to shore

Sections of the Herolds Bay seawall

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IMIESA January 2020

An aerial perspective showing the wall layout

Bearing the brunt of the storm

ENVIRONMENTAL ENGINEERING

PROJECT TEAM

Terraforce wall construction in progress

of the wall was finished off with an in situ concrete coping.

Terraforce L13 blocks were chosen due to the substantial constructed mass that they offer. Approximately 13 500 units were produced using a 30 MPa concrete mix formulated by Mobicast, a Terraforce-licensed manufacturer. A minimum of 400 kg cement was specified per cubic metre of concrete.

“The stepped wall creates an accessible inter face between the beach and the roads/lawns,” Goedhart continues. “The blocks could also be easily secured

Storm damage

together with reinforced concrete and the transition to ramps and stairs was easy to achieve.”

Design endurance Since its completion in October 2004, the new seawall has successfully deflected the force of the sea; however, the particularly heavy storms experienced in 2006 and 2008 did result in some subsequent lowlevel damage that required remedial works.

At one point where the bedrock had been too deep to reach during the 2004 works, the foundation had been undermined, and

Engineers: Tuiniqua Consulting Engineers, George Contractor: New Heights Terraforce blocks: Mobicast

a small section collapsed. This was rebuilt on reinforced concrete caissons that were sunk down to the rock level. A gabion mattress apron was included below normal beach level to prevent a new collapse.

At another section, relatively minor damage occurred as a result of the drainage behind the wall proving inadequate to deal with excessive and rapid water ingress.

This was easy to fix, with the section being reinstalled with better drainage measures. So far, these measures have lasted until today, weathering any further power ful storms.

ENVIRONMENTAL ENGINEERING

Repairing a flood-damaged spillway Commissioned by Eastern Produce Estates SA (Epesa), the remediation of the Mambedi Lower Dam spillway represents a major feat of engineering, comprising the integration of complex structures that blend in with the environment.

By Kyle Poolman and Pieter Gouws*

L

ocated 40 km east of Louis Trichardt in Limpopo, Mambedi Lower Dam is a key water source for macadamia nut farmers, so any threat to its supply has major downstream implications. Such an event occurred when the dam suffered large-scale damage during an extreme rainfall event in February 2000. The water discharge nearly reached the regional maximum flood (RMF) peak.

The event damaged the existing concrete overflow structure and spillway channel on the right bank, leaving in its wake a nearly 80 m wide, 15 m deep donga through which water flowed freely, drastically reducing the dam’s overall capacity.

Epesa appointed PG Consulting Engineers as the main consultant for the repair of the dam’s spillway. This was based on a design for discharge just higher than the RMF. The spillway design required a full spectrum of upand downstream erosion and scour protection, as well as reinforced channel wing walls and embankment. PG Consulting approached Maccaferri Africa for assistance in designing these various water channelisation structures.

Construction started in July 2017. The overall project required the implementation of more than 12 000 m3 of gabions, Reno

mattresses and Terramesh® structures, as well as 25 000 m2 of varied geotextiles and 10 000 m2 of geosynthetic soil reinforcement.

Gabion spillway Conceptualising and later detail design of the new spillway required a rigorous repetition of ideas in order to produce an amicable and cost-effective solution for the client. The dam wall was designed as an embankment wall

by PG Consulting. Selecting the appropriate spillway was subsequently affected by various factors including the presence of some highly dispersive soils on-site, the height of the eroded embankment faces, and peak water velocities modelled as reaching almost 6 m/s.

The spillway was designed as a stepped gabion weir, with an approach apron created out of 0.3 m Reno mattresses underlined by a geotextile and an impervious liner to assist in preventing seepage through the dam core. The spillway embankment was created using a clay core to this effect as well.

A stepped gabion weir was implemented in the down chute of the spillway and currently reaches 9 m high. This was meticulously constructed, with the eventual inclusion of a concrete capping on the steps in order to protect the underlying mesh from any possible

damage due to debris crossing through the spillway during overflow.

Stepped gabion spillways have proven energy dissipation attributes due to factors such as water flow through the porous units, as well as significant aeration of water undergoing nappe or skimming flow as it flows down the steps.

This, coupled with a gabion structure’s ability to absorb a degree of differential settlement without compromising structural integrity, led to the decision of using an 80 m wide stepped gabion weir structure as the outlet of the spillway. A downstream stilling basin is also instituted using gabion energy dissipators and two counterweirs, as well as a mattress lining to prevent erosion of the underlying soils. The importance of implementing this ‘armour layer’ (in the form of Reno mattresses) in the stilling basin cannot be overstated: one of the causes of hydraulic structure failures is scour of soil at the toe, especially where flowing water meets erodible material.

The stepped weir was designed using Maccaferri’s MacRA (Maccaferri River Analysis) 2 software, with the stilling basin and approach apron lining checked using Maccaferri’s MacRA 1 software outside of the standard hydraulic design undertaken by PG Consulting.

Once hydraulic stability was confirmed, all

The new Mambedi Lower Dam spillway (Credit: Janes Gouws)

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ENVIRONMENTAL ENGINEERING

ABOVE LEFT Failed concrete overflow structure and prevailing donga LEFT Reno mattress approach apron enclosed by two wing walls ABOVE Spillway under construction: a view from tier 7 of the stepped gabion weir (Credit: Juan-Louis de Beer)

structures were checked for static stability using Maccaferri’s MacStARS 4.0 software.

Embankment protection With the decision being taken to implement a stepped gabion weir, attention turned to stabilisation and reinforcing of the wing walls on approach to the spillway, as well the embankments enclosing the stilling basin. The decision was taken to implement a reinforced soil structure (RSS) using a combination of geosynthetic soil reinforcement of varied

Soil on slopes

tensile strengths (in the form of Maccaferri’s Paragrid® geogrids) as primary reinforcement, as well as Terramesh units (gabion units with double-twist steel-wire mesh tails) as secondary reinforcement.

A MacLine SDH 150 geomembrane liner was installed behind the facing to limit the amount of water ingress into the structural fill, along with longitudinal subsoil drains to enhance the structure’s resistance to saturation. The Terramesh walls range from 4 m to 15 m in height and are designed in conjunction with geogrids of up to 150 kN/m tensile strength, checked using Maccaferri’s MacStARS 4.0 software in conjunction with BS 8006:2012 (code of practice for strengthened/ reinforced soils and Soil on other fills). slopes

The amalgamation of various structures into a single spillway of this magnitude requires the use of resources such as this 3D model created by the team at Maccaferri Africa (Credit: Barend Byliefeldt)

Conclusion The remediation of Mambedi Lower Dam will ensure improved water capacity,

providing water for livestock and farming activities in the greater Mambedi area.

Construction also stimulated job creation, with local labour being used to place and pack thousands of cubic metres of gabions and Reno mattresses. A project of this magnitude also required quality control that is second to none, including special resources such as drone imagery and 3D CAD models in order to assist the contractor in accurately constructing this mammoth structure.

The project was completed in September 2019 and received a Commendation for Technical Excellence from the South African Institution of Civil Engineering in October 2019. *Kyle Poolman, BEng (Civil), is an area manager at Maccaferri Africa and Pieter Gouws, Pr Eng, is the managing director of PG Consulting Engineers.

The 1.5 m gabion counterweirs were designed with ‘ramps’ in order to allow any wildlife that may wander into the large basin to traverse freely

IMIESA January 2020

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DAMS & WATER STORAGE

For retention dams that retain a water body as an attractive urban feature, an automatic scour gate can be used

The progressive onset of climate change is having a major impact on weather patterns, with extreme rainfall events becoming common. Urban flash flooding poses significant health and safety risks, and needs to be countered with engineered solutions. By Peter Townshend*

Urban flood control

E

xtensive urbanisation within South Africa’s cities and periurban areas has resulted in more hard surfaces being introduced into the catchments of urban water courses.

During heavy rainfall periods, this leads to high, short-duration floods that cause havoc.

In most of the well-established cities, the stormwater infrastructure is old and inadequate, and often blocked with litter and debris. Consequently, stormwater overflows

FIGURE 1 Typical routing of a flood hydrograph through fixed-orificetype outlet

and runs into the streets, flooding and damaging properties. As volumes subside, this surplus stormwater eventually enters and discharges into urban watercourses via piped systems.

For informal settlements bordering rivers – often below the flood line – shacks and belongings are frequently swept away.

Sadly, lives have also been lost, as was the case during the Easter 2019 floods in KwaZulu-Natal.

Most new developments are required to incorporate a stormwater retention facility.

Conventional structures have a fixed pipe or pipes under an earth embankment. The

Informal settlement on the banks of the Jukskei River in Alexandra

discharge after the pipes are submerged is controlled by the orifice flow formula.

The pipe sizes and height of the embankment are sized to restrict the outflow to a maximum permissible to minimise downstream flooding, or to the pre-development run-off peak. However, it requires valuable unused urban land to create the retention facility behind the pipe or culvert outlet in order to attenuate the peak flow (as shown in Figure 1).

Optimising retention space A more effective way to attenuate the inflow, as well as reduce the valuable space required for the retention facility, is to have a larger outlet, but with a control mechanism. This will discharge all flow up to the maximum without restriction, and then will control the outflow automatically to the maximum allowable discharge downstream.

The surplus water will

FIGURE 2 Using a controlled outlet to save on space for the retention of the flood waters

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DAMS & WATER STORAGE

FIGURE 3 Typical application of a controlled outlet to reduce the storage requirement for the flood

the downstream side to limit the discharge to a maximum amount to prevent flood damage downstream.

then be stored in a smaller-sized retention facility (as shown in Figure 2), which is a saving in valuable urban space.

These automatic control devices can either be diaphragm valves, for smaller urban developments, or canal control gates for larger urban watercourses (as shown in Figure 3). The downstream discharge is measured through a measuring weir, such as a partial flume.

Sediment and litter

Float control Both items of equipment are controlled by a float set to control the level of discharge through the measuring weir. If the water level is below the maximum discharge level, the equipment will remain open, but if the water level rises slightly above the maximum discharge level, the float will cause the diaphragm valve or canal gate to close slightly to maintain the maximum flow.

For retention dams that retain a water body as an attractive urban feature, an automatic scour gate can be used. This will retain the water body but will open during urban floods to release sediment-laden water. It is also controlled automatically on

Detention and retention dams also serve an important function in dropping out sediment, as well as depositing litter and debris along the water edge. As the flood recedes, litter can be easily collected. The sediment load from urban areas is large due to building and construction activity in the catchment.

Urban flooding will only get worse due to climate change. Therefore, measures must be taken to reduce the devastating effects of flooding. The building of retention dams alongside watercourses is key. Municipal authorities need to make provision for them by identifying suitable locations.

Within Johannesburg’s Alexandra township, for example, undeveloped land bordering the Jukskei River provides an ideal opportunity for the city to install retention facilities.

Once installed, these would certainly help to alleviate the annual and devastating peak flows that cause so much hardship, particularly for informal dwellers housed on the river’s banks.

ABOVE A diaphragm valve used as an automatic device to limit downstream flows

RIGHT Scour gate in KZN to pass flood waters through a weir and remove sediment 2019 Durban Easter floods

*Peter Townshend, Pr Eng, is the managing director of Amanziflow Projects.

AUTOMATIC WATER CONTROL EQUIPMENT • Spillway gates • Scour gates • Release fuse gates • Canal regulating gates • Diaphragm regulating valves • Increased water supply in dams • Sediment removal • Trouble free river offtakes • Canal flow control • Inlet control to reservoirs and dams No Electrical supply or human intervention required

No Human or Electrical intervention Required

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www.amanziflow.com info@amanziflow.com +27 082 704 1952

www.amanziflow.com

CEMENT & CONCRETE

Levelling the cement playing fields In addition to presenting their case to the chairpersons of some Parliamentary portfolio committees and unions, the South African cement industry has approached the International Trade Administration Commission of South Africa (ITAC) for a safeguard action to counter cheaper-priced imports that threaten to undermine the local sector. By Alastair Currie 42

IMIESA January 2020

T

he steady contraction in the South African cement manufacturing sector is indicative of the tough times being experienced in construction and the broader economy. This is due to a range of factors. Chief among these is a decline in public sector infrastructure expenditure, the poor performance of stateowned enterprises, lower investor appetite, and the generally high cost of doing business in South Africa.

Competition for fewer projects has forced many companies to bid at uneconomic levels, with price sensitivity intensifying. From a procurement perspective, this has opened the door to cheaper-priced imports, some of which may not comply with South African quality standards.

South Africa’s cement sector has a combined capacity of around 20 million tonnes annually. Currently, the actual local output is approximately 13 million tonnes, or 60%

of capacity. Despite this, cheaper imports continue to flow into the country.

During 2018, around a million tonnes of cement entered South Africa from countries like China and Vietnam, at prices as much as 45% lower than those of South African producers. That represents a loss of around R1.3 billion that could have been spent in the local economy. Approximately 350 441 tonnes of cement were shipped to South Africa for Q2 2019 – the most since Q3 2015. Imports from Vietnam amounted to 301 872 tonnes. Total imports have increased by 139% since 2016.

At this stage, the main buyers appear to be SMME-type builders; however, there is a concern that some of these imported products could end up forming part of important infrastructure projects.

Strict compliance Cement produced in South Africa must comply with compulsory standards. In turn, all cement

CEMENT & CONCRETE

used on local construction projects requires a Letter of Authority (LoA) issued by the National Regulator for Compulsory Standards (NRCS).

Every producer/importer must also appoint an NRCS-approved certification body – typically the SABS. However, the local cement industry questions whether all importers are compliant.

“In the case of imports, every 500 tonnes must be sampled and tested by the SABS or equivalent,” explained Bryan Perrie, managing director, The Concrete Institute (TCI), speaking during a TCI-hosted media site visit to PPC Cement’s Dwaalboom operation in Limpopo.

“On successfully passing the test, the certification body issues a certificate that is then submitted to the NRCS to obtain an LoA. This makes the process fair and transparent, as long as everyone complies,” he continued.

TCI acts as an independent body representative of the cement, concrete and broader construction industry to interact effectively with government and regulatory bodies. TCI members comprise AfriSam, Lafarge, Natal Portland Cement, PPC Cement, and Sephaku Cement.

As Perrie pointed out, South African cement producers are not trying to prevent imports. “It’s about ensuring that everyone competes on an even footing and according to set standards and legal requirements,” he explained. “This helps to ensure the overall safety of downstream concrete products and traceability of the cement when a forensic investigation is required.”

Discounting quality is not an option and South Africa’s cement producers remain committed to providing world-class products. Despite the downturn, for example, the South African cement sector invested around R1 billion in equipment, plant and property during 2018.

Unlike importers, local companies have the added expense of complying with BBBEE legislation, Mining Charter social and labour plan (SLP) stipulations, a large increase in

energy costs, and the new carbon tax – the latter translating into a 2% increase in local selling prices. That’s in addition to the spiralling costs of manufacturing and transporting cement to market in South Africa. The South African cement sector also pays local taxes, which contribute to the government’s fiscus and national development. Simply put, the current barriers to entry for importers are too low and, therefore, uncompetitive.

The cement industry is a vital component of the South African economy and critical to delivering on government’s infrastructure mandate and re-industrialisation programmes.

The cement industry is also a major employer, with most of the country’s 17 plants located in rural areas where they serve as key socioeconomic contributors.

According to TCI, Stellenbosch University research shows that the construction industry accounts for 8% of total formal employment and 17% of total informal employment in South Africa. The cement sector directly employs more than 7 000 people and indirectly an additional 35 000 jobs are affected.

“Unless we collectively take steps to protect our industry, the cement sector as a national asset will be progressively eroded, leaving the country increasingly dependent on foreign imports,” said Perrie.

Countering with tariffs Imposing tariffs was an effective measure in the past when South Africa started receiving imports from Pakistan in 2014. The cement industry approached the ITAC with a request for anti-dumping tariffs against Pakistan. They were implemented at between 14% and 77%, depending on the source plant, and were very effective in curtailing imports.

The key challenge is that anti-dumping tariffs are country specific. As imports started tailing

off from Pakistan, they began picking up from China and Vietnam.

In August 2019, TCI applied to the ITAC for a safeguard action. If the ITAC agrees, this will impose a general tariff on all imported cement. “They came back with a deficiency letter, which is essentially a request for more information. This has now been submitted,” said Perrie.

TCI has also applied to the Department of Trade and Industry for designation status. Sectors that are designated must have a specified percentage of local content. If approved, all government-funded projects will have to buy local cement.

Community participation “Cement is key to the GDP mix for South Africa,” said Njombo Lekula, managing director: South Africa, PPC Cement, also attending the PPC Dwaalboom site visit. “Currently, local cement pricing is at 2008 levels. However, operational and compliance costs have continued to climb year on year. However, as an industry, we remain committed to giving back through SLP and other socio-economic and related transformation initiatives.”

The backlog of rural development is huge.

While government has the primary responsibility for infrastructure development in these areas, PPC, alongside other local producers, willingly accepts its civic and moral responsibility to assist.

At PPC Dwaalboom, for example, investments by the producer have greatly improved the quality of life for communities living within the vicinity of the plant. These projects also support local government infrastructure initiatives. A prime example is an SLP project undertaken for Thabazimbi Local Municipality. This entailed an approximately R2.5 million investment to upgrade a pump station. PPC is also investing in gravel road upgrades in the area, in conjunction with government. Other SLP initiatives for Moses Kotane Local Municipality include the construction of a reservoir and water supply to the Holfontein community, and an approximately R1.3 million facelift for Mochudi Secondary School. Like other producers, PPC also invests extensively in training and skills development.

“Together with government, cement producers are restoring hope and making positive change for communities. In turn, government must protect local industry,” added Perrie.

“Going forward, a partnership approach between the public and private sector is an essential component. A potential collapse in the cement and broader construction sector must be prevented at all costs,” Perrie concluded.

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CEMENT & CONCRETE

Bryan Perrie, managing director, TCI

Five costly housing errors to avoid

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sing the correct mix proportions and ensuring good site practice affect the strength, durability and economy of the finished concrete.

“First, the quality of the cement is crucial,” stresses Bryan Perrie, managing director of The Concrete Institute (TCI). “This is particularly important at present, when tonnes of imported cement of questionable quality are arriving at our ports.

“Building contractors should note that all producers and importers of cement must have a Letter of Authority (LoA) from the National Regulator for Compulsory Standards (NRCS) for each different cement type sold in South Africa.

The NRCS issues an LoA only if the cement standard complies with the required South African standards,” he explains. The validity of an LoA can be checked with the NRCS. Perrie says five common errors tend to occur when producing concrete for housing: Sand is a key ingredient in the concrete mix

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Substandard results occur when builders miss critical steps in the concreting process.

- Not realising that the ratio between the water and cement in a mix determines the strength of the concrete. “When site batching for small quantities of concrete, contractors tend to use a builder’s wheelbarrow as a unit of measurement, but this practice often produces inconsistent concrete mix proportions,” he explains.

“The contractor should ensure that the wheelbarrow is always levelled off at the top when measuring materials for mixing, to ensure that the correct, consistent mix proportion is achieved throughout. It should also be noted that two bags of 50 kg cement are equivalent to one builder’s wheelbarrow,” Perrie states.

- Another common mistake on-site is the addition of extra water to improve the workability of the concrete after an extended period of time. Simply adding more and more water significantly reduces the strength of the concrete - Concrete is often not cured using the proper technique and/or is not cured long enough.

“Newly cast concrete must be cured to ensure that hydration continues until the full potential strength of the hardened concrete is achieved and to minimise the tendency to crack. The concrete should be kept damp and not allowed to

Simply adding more and more water significantly reduces the strength of the concrete

freeze during this time. The concrete should be cured for at least five days after placing it and longer in cooler weather,” he advises.

- There is often confusion between client, specifier and contractor when it comes to finishing a concrete floor. In general, a sandcement screed should not be applied as the final wearing surface. The appropriate application of sand-cement screeds and concrete toppings is described in detail in a TCI publication, entitled ‘Sand-cement screeds and concrete toppings for floors’, which is available free of charge from TCI and downloadable from its website at www. theconcreteinstitute.org.za.

- Cracking in plaster and floors is a very common problem on most sites – a problem that can be avoided or reduced through the use of the correct types of joints to allow for movement of the structure at appropriate intervals. “Care should also be taken to allow for the movement joints between different material types, such as clay bricks and concrete blocks,” Perrie adds.

More detailed information on this subject is available from TCI’s ‘Concrete basics for building’ publication. Other specialised information leaflets on these issues can also be obtained directly from the Institute. TCI’s School of Concrete Technology also presents a variety of educational courses on concrete for all levels of experience.

CEMENT & CONCRETE

Profit above quality

The problem with 32,5 grade cement Be careful of which cement you use on your project. Although 32,5 grade cement may seem cheaper by the bag, you need 1.5 times more to achieve the same strength as 42,5. It poses serious risks in terms of strength and quality, says Anton Weavind, director of Mamba Cement, South Africa’s newest cement plant.

S

ome grades of 32,5 cement contain high volumes of fly ash and are not intended for use in general construction. In their quest for profitability, some producers and blenders make 32,5 cement where large amounts of fly ash bulk up their products.

Fly ash is abundant and cheap in South Africa, so profit margins are much higher.

The problem is that fly ash only starts to strengthen from 28 to 40 days, which means that 32,5 cement poses serious risks for most building applications.

Modern construction takes place at a rapid pace and builders don’t have time to wait for long curing times. The result is that their concrete does not reach its specified strength and buildings are compromised.

For general construction, fly ash in cement offers no benefit or value. However, for the cement producer or blender, it offers the chance to cheaply bulk up a bag of cement while still adhering to current South African regulator y standards. The more fly ash, the higher profit per bag.

WINNERS Producers & blenders of 32,5 cement LOSERS Customers, builders, projects “Just like you cannot add water to petrol and expect the same per formance or water to beer and expect the same strength, adding fly ash to cement only ser ves to reduce the quality and per formance” says Weavind. “Because of this, Mamba Cement produces 42,5R cement. It achieves the desired strength quickly, offers the best quality and better value bag-for-bag”.

The Synagogue Church of Nations building in Lagos, in which 115 people died (85 of whom were South Africans), collapsed on 12 September 2014

Banning the use of 32,5 cement China and many African countries, notably Nigeria, have restricted or even banned the use of 32,5 grade cement in construction. Concerned with a spate of building collapses and profiteering by cement manufacturers, Nigeria has changed policy on cement, which urges manufacturers to produce 42,5 instead of 32,5 grade.

Cheaper is more expensive 42,5 cement vs 32,5 cement

42,5

Cement

=

42,5 cement contains higher volumes of clinker, the ingredient that ensures strength from an early stage. This ‘pure’ cement reaches strength early after mixing, which allows construction to continue.

32,5

Cement

32,5

Cement

32,5 cement contains less clinker and more inactive fly ash, therefore more bags are needed for the same strength result. In fact, a builder would need 1.5x more to achieve the same strength.

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Audit systems for readymix and clay brick operations

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ndustry association ASPASA is extending its safety, health and environmental audits to include non-mining-related activities, including readymix, concrete and brick plants.

In many instances, these plants are Nico Pienaar, located close to the quarry or mine, or director, ASPASA even situated on the mine and make use of minerals extracted there. However, if the plants are not situated within the mine’s boundaries, they are not covered by the Mine Health and Safety Act (No. 29 of 1996), but rather need to comply with the Occupational Health and Safety Act (No. 85 of 1993). Similarly, a comprehensive environmental audit is also available based on ASPASA’s internationally acclaimed audit system, the About Face programme.

According to Nico Pienaar, director, ASPASA, the audits were developed on ISO principles and tailored to South African conditions. Guidelines and documentation are supplied to members to ensure compliance with legislation and ASPASA best practices, after which the annual audits are conducted to ensure conformity.

Inexpensive, easier to implement “The audits address the needs of the industry, as they are designed to be inexpensive and easier to implement than existing programmes,” he explains. “Yet, they are every bit as comprehensive and easily ensure that the plants audited will have the right systems and procedures in place to guarantee compliance with all legislation and best practices.

“It is especially convenient for plants that operate both the quarry or mine, as well as the auxiliary plant off-site. Rather than using multiple suppliers, the company can simply make use of the existing auditors for fewer complications,” Pienaar continues.

Audits are conducted by an independent auditor well versed and better able to work quickly and efficiently through each site with the least possible disruption. Upon completion, the auditors also compile a noncompliance report that can be used to take immediate remedial actions.

It makes sense to use a professional supplier with specially developed programmes to ensure the health and safety of the site, as well as ensure that the operation is run with the least environmental impact.

CEMENT & CONCRETE

Marine protection for Point Promenade

T

he extension and renovation of the Durban Point Promenade forms par t of a larger-scale development within the city’s water front precinct.

Constructed by Stefanutti Stocks as the main contractor, it was designed with a suspended ground floor slab, with ground beams supported on CFA piles, pile caps and associated connections.

In the ver y unlikely occurrence of a massive storm surge breaching the hightide mark, the foundations – together with a sheet pile wall – will ensure the structure remains intact. A comprehensive series of Sika products was also specified to maximise aesthetics and provide extended durability for this massive concrete structure.

On the lower club and promenade level, Sika Antisol E curing compound was used to cure the concrete. In turn, Sika’s Separol GU ZA shutter release oil was used on all the steel formwork, which formed part of the columns on the promenade and lower club level that support the upper deck. All the walls and facades on the lower club level were primed and sealed with Sika Primer-3N and Sikaflex Construction.

For the construction and expansion joints in the existing effluent trench, plus

Sikagard-705 L Silane was used as a concrete protection treatment on the front face of the structure below the cantilever to counter the ingress of chlorides

the lower club and promenade level, Sika’s closed-cell polyethylene backing cord was used as a joint former, followed by Sika Primer-3N as a joint primer to the face of the joints. Given the importance of the joints and the requirement for a totally waterproof seal, Sikaflex Pro-3 i-Cure was specified for this crucial task. The Sikadur-31 DW and Combiflex SG bandage system was recessed below the Sikaflex Pro-3 i-Cure as a secondary seal to ensure all joints would be totally watertight.

On the top promenade level, Sikadur-52 ZA, which is a low-viscosity crack injection resin, was used to permanently fill all shrinkage cracks

in the upper deck concrete structure.

Sikalastic-152, applied together with a glass-fibre mesh, ensured a watertight barrier over all these shrinkage cracks.

Additionally, the stainless steel handrails along the promenade were anchored using SikaGrout-212.

Finishing touches included the application of SikaTop Armatec-110 Epocem bonding primer, together with Sika’s Monotop range of mortars for general defects. To counter the possibility of graffiti, and facilitate its removal, Sikagard-850 AG, a singlecomponent anti-graffiti coating, will be applied on the northern and southern side of the promenade.

To mimic the habitat of waves gently caressing the shoreline, the cantilever on the seafacing side was designed with lines and curves

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WASTE MANAGEMENT

The need for a new approach South Africa lags key developed countries by approximately 20 to 30 years in the field of sustainable waste management practices. While this presents environmental threats, it also creates exciting opportunities to reverse the present situation and establish a much-needed secondary resource economy.

By Alastair Currie

A

keynote speaker at Landfill 2019, Professor Linda Godfrey – principal scientist at the CSIR and extraordinary associate professor at North-West University – delivered a presentation entitled ‘Why the diversion of waste from landfill requires improved landfill management’. This highlighted the intrinsic value of domestic solid waste and provided practical solutions for capitalising on the worth of viable materials discarded annually, which runs into billions of rand. Alongside this is the urgent need to tackle current landfill management practices.

These include the need for transitioning current uncontrolled and controlled dumpsites to engineered landfills; improved operation of disposal sites, including ensuring that incoming waste is compacted and covered correctly; and greater compliance with licence conditions.

Improved education and awareness are also required to address the often intentional burning of waste, which presents a major environmental impact.

Professionally engineered airspace utilisation must focus on containing non-productive waste, while creating separate solutions

Professor Linda Godfrey, principal scientist, CSIR

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for collecting and sending back productive materials for reuse, recycling and recovery.

The process requires greater private sector involvement in the form of public and private sector partnerships to enable the diversion and commercialisation of reusable waste long before it reaches any landfill site.

However, the starting point is to ensure that every landfill is designed and built to ensure that their composite geosynthetic lining systems are functional and effective.

Every landfill must also have a comprehensive closure plan in place.

WASTE MANAGEMENT “The Department of Environment, Forestry and Fisheries went through a process some four years ago to have all landfill sites licensed for operation or closure,” said Godfrey. “However, are the compliance conditions understood and are we now monitoring compliance against these licence conditions? We need to work collectively to ensure that this happens.”

Profitable waste streams From a commercial standpoint alone, Godfrey pointed out that by targeting just three main municipal solid waste streams, some 60% to 70% of waste (by mass) could be diverted from landfill towards value recovery, in the process creating much-needed jobs. These streams comprise construction and demolition waste, organic waste, and paper and packaging waste.

Currently, informal waste reclaimers are filling a major recycling gap by collecting and introducing recyclables into the South African value chain, but a more coherent strategy needs to be implemented to integrate and uplift this sector on a broader scale. Examples include the widespread introduction of separation at source, the development of materials recovery facilities, greater support for SMMEs, and Department of Trade and Industry support for secondary

manufacturing – ensuring much needed end-use markets. One of the pressing concerns raised by the African Reclaimers Association is the need for funding support and access to equipment and facilities.

But how far have we come in moving up the waste hierarchy in terms of current legislation?

Sadly, we still predominantly collect, transport and dump. According to the last official government statistics (2011), as much as 90% of our waste is still sent to landfill. That equates to at least R17 billion worth of resources being thrown away in a hole in the ground annually, despite the waste hierarchy being embedded in our waste policy.

“While there’s always an opportunity to go back and mine these disposal sites at a later stage, that doesn’t address the immediate socioeconomic and environmental priorities,” said Godfrey. “The cost of remining a landfill site is very expensive. And where this does occur in Europe, for example, the motivation is often the value of the land itself for future developments.”

Leapfrogging the gap Can developing countries leapfrog from uncontrolled dumping to a circular economy without going the route of destructive technologies, such as incineration, adopted by developed nations? Some international

experts believe not. “However, I believe it is possible, as we’ve been implementing aspects of a circular approach for decades now – granted, driven more by need than by design,” Godfrey continued.

“We can drop technologies into South Africa tomorrow, with some level of localisation where required, using available proven technologies,” she asserted. “We don’t need to reinvent the wheel when it comes to technology uptake.

With adequate PPP funding, the potential will be far greater in terms of coordination and execution.”

The main issues seem to be a lack of alignment when it comes to agreeing on which technologies are most appropriate for South Africa, the lack of political will to make the transition, and a lack of investment in alternatives. Godfrey recommended focusing on simple strategies that yield immediate returns, which comes back to the three main municipal waste streams mentioned earlier.

By diverting these three waste streams, only 20% to 30% residual waste is left. This waste “can instead be disposed of at fewer, regional engineered landfill facilities that are correctly designed, constructed, operated and monitored,” said Godfrey.

Are SA’s landfills too cheap?

Can it be accomplished right now? The answer is yes. “A question I often put to municipal officials is, ‘What would you do if you woke up tomorrow and didn’t have a landfill?’” said Godfrey.

“The responses typically include statements like ‘We’d implement separation at source; we’d compost our organics; we’d drive greater recycling.’ My response then is, ‘Why aren’t you doing it already?’”

Clearly stated, it is too easy to collect and dump our waste and it’s ostensibly cheaper… or is it? Municipalities sometimes state that alternatives like the compositing of organic waste are too costly. Relative to current landfilling, yes, but consider

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the downstream commercial benefits for farming communities.

The more direct question is to ask municipalities what their airspace is worth to them. The responses are certainly revealing, ranging from R100 to R600 per tonne, as there is no standard tariff scale. Simply put, South African airspace is still cheap, relative to alternative technologies, and sometimes free in the case of municipal dump sites that don’t provide weighbridge assessment and charging.

In the EU, the cost per tonne easily exceeds R1 000 in many countries, plus some impose an additional tax to discourage landfill disposal. In the UK, gate fees are dependent on the downstream process technology, with fees increasing from composting to anaerobic digestion, to landfilling.

“South Africa still has a way to go in these respects,” stated Godfrey. “One of our key challenges is our price-sensitive approach. In response, we must transition to engineered landfills, as this serves twin purposes: to reduce the environmental impacts of our current dumpsites, and to increase the capex and opex costs of landfill sites, which will automatically increase our disposal costs, making alternative waste treatment technologies more competitive.

“Right now, landfilling remains South Africa’s predominant technology choice and, for this reason, the country’s secondary resources economy is not growing. That’s not sustainable on all fronts and requires urgent public and private sector engagement to map the way forward,” she added.

“The most recent Greenhouse Gas Inventory for South Africa showed that the waste sector was the second largest contributor to total methane emissions in 2010, contributing 37.2% of total methane. By applying our collective wills and minds, we can mitigate this threat while unlocking a circular vision that creates new jobs and a sustainable future that preserves our country” Godfrey concluded.

TRANSPORT, LOGISTICS, VEHICLES WASTE MANAGEMENT & EQUIPMENT

Accelerating concrete paving projects Wirtgen’s investment in technology is making slipform paving faster and more cost-effective.

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ompatible with Wirtgen’s SP 15i und SP 25i slipform pavers, AutoPilot 2.0 eliminates the need to measure, mount and remove stringlines. The 3D system is suitable for paving concrete safety barriers, curbs, gutter profiles, or traffic islands, in addition to road surfaces with a width of up to 3.5 m using the inset method and 2.5 m using the offset method.

The 3D control system includes a tablet that both controls the machine and is attached to the Field Rover survey pole. Two GPS receivers mounted on the machine communicate with a GPS reference station at the job site.

“The global navigation satellite system (GNSS) controls the steering and transverse tilt of the slipform paver fully automatically,” explains Waylon Kukard, sales manager, Wirtgen South Africa. “In combination with an ultrasonic sensor or a robot-controlled total station, it also precisely controls the machine height. Thanks to a certified standard interface, the SP 15i and SP 25i can be equipped with AutoPilot 2.0, as well as 3D systems from other leading suppliers.”

Sensors on the machine take highly accurate readings during the paving process. These systems constantly compare the target and actual values of the paving parameters. If a The Wirtgen SP15i slipform paver communicating with the AutoPilot 2.0 field rover

digital 3D terrain model is not available for a project, the Wirtgen Field Rover can be used to generate a new digital data model directly on-site. A further plus is that existing machines can be easily upgraded with AutoPilot 2.0.

“In the case of composite radii or tangent sections, where it is important that all the tangents are dead straight, the process saves an enormous amount of time,” explains Kukard.

He cites the feedback from US company Talley & Armstrong, which is one of the first concrete contractors in North America to upgrade to AutoPilot 2.0.

“Their experience provides a strong business case for AutoPilot 2.0’s adoption in the South African market,” Kukard continues.

Customer feedback According to Talley & Armstrong’s Clay Armstrong, the first AutoPilot system was already easy to use, but upgrading the SP 15i with the new system brings other major benefits.

Paving a curb gutter profile

“The AutoPilot 2.0 system is much more userfriendly,” Armstrong explains. “The system gives us the ability to make changes to the model regardless of whether it was imported or created from ground points or the usual stakes set up for curb/gutter profiles.

“We can change both the vertical and horizontal alignment during the paving process to compensate for any defects. Changes to the vertical curve were difficult or not at all possible with the previous version,” says Armstrong.

“Now we can make numerous changes and even delete or add points to an existing model.

“We can change individual points on a vertical curve and pull them apart as far as it takes to smooth a route. If we know, for example, that point A and point B are connected by a straight gradient, we can theoretically delete all intermediate points that don’t match or return to the original model. And we can also change the percentage of the gradient in the model if we find that it’s incompatible with on-site conditions,” he adds.

Talley & Armstrong has eight Wirtgen moulds, ranging from a curb gutter profile 15 cm wide to a 1.50 m wide sidewalk mold. An adapter plate also makes it possible to attach the moulds from an older paver to the SP 15i.

“We believe that slipform paving as a technology has major growth potential within our regional market, creating opportunities for contractors at all levels. The introduction of AutoPilot 2.0 is a prime example of how Wirtgen has simplified the technology without compromising on quality results,” Kukard concludes.

IMIESA January 2020

51

TRANSPORT, LOGISTICS, VEHICLES & EQUIPMENT

Equipment selection and utilisation is a key differentiator for construction contractors as margins shrink and competition intensifies across Southern Africa.

Bomag provides the competitive edge

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ounded in Eswatini in 1982, Inyatsi Construction Group Holdings works locally as well as cross-border in neighbouring countries that include South Africa, Mozambique, Namibia and Zambia. Projects range from road and bridge construction to multistorey buildings, water purification works, shopping malls, airports, irrigation schemes and township developments.

“Ours was the first company in Eswatini to recognise the advantages of working with articulated dump trucks (ADTs), when we bought four Bell B18A ADTs from Bell Equipment back in 1991,” says Kevin Grey, production technology manager, Inyatsi.

“Thereafter followed more Bell 18 t, 20 t and 25 t ADTs and articulated haulers across the proven D- and newer E-model ranges.

This equipment has formed the backbone of our material haulage fleet for many years on large infrastructure projects and aggregate quarries,” he continues.

The Bomag BF300P paver is capable of paving up to 300 tph and widths from 1.7 m up to 4.2 m, making it suitable for both highway and township work

L-R: Donald Bokkelkamp, plant manager, Inyatsi Construction Group Holdings, with Charlie Boucher, manager, Bell Swaziland, and Kevin Grey, production technology manager, Inyatsi

Compaction and asphalt Inyatsi’s Bomag compaction fleet is also supplied and supported by Bell Equipment.

Included in the fleet are Bomag BW212 smooth-drum and padfoot rollers, a Bomag BW24RH pneumatic-tyred roller, Bomag tampers and walk-behind rollers, and a Bomag MPH125 recycler.

Recently, Inyatsi expanded this line-up to meet production demands on largerscale projects in Eswatini. These include the construction of a 30 km long water canal from Lusip Dam to the Lusip Irrigation Scheme.

“We bought three Bomag BW211 smoothdrum rollers with padfoot clamshells and 30 Bomag BVT65 tampers that were used extensively to compact backfilled sections,” says Donald Bokkelkamp, group plant manager, Inyatsi.

Inyatsi was also recently awarded two major roads projects of 11 km and 14 km, respectively, to complete the route connecting the new Mswati III International Airport to Manzini.

Combined, the Inyatsi management team has in excess of a 120 years of experience in asphalt production and paving. The asphalt plant situated at Sikhupe is a Ciber iNova unit capable of mixing up to 120 tph. The plant is a continuous counterflow type with a pugmill mixer that ensures proper binder coating and homogeneous mixes.

At the heart of the operation is a Bomag BF300P capable of paving up to 300 tonnes per hour and widths from 1.7 m up to 4.2 m, making it suitable for both highway and township work.

“Proper compaction is vitally important and is ensured with the use of the compacting screed of the Bomag BF300P paver, which in turn is supported by the use of a Bomag BW141AD50 vibratory double-drum roller with an operating weight of 7 t,” Bokkelkamp explains. “The drum width of 1.5 m ensures an excellent static point loading of 23 kg/cm or 75 kN.” The Bomag BW24RH pneumatic-tyred roller rounds off the final compaction. This roller has an operating weight of 24 t, which can be increased to 27 t with additional ballast.

To further support its road teams, Inyatsi has also added three new Bell 670G graders, two of which have been fitted with Trimble laserlevelling equipment.

BUILDING MATERIALS

Face brick forms part of iconic design The newly built Mcebisi Michael Msizi Public Library in the Eastern Cape provides a dedicate learning space constructed from face bricks – a mutually aesthetic and economically sound building material.

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he Mcebisi Michael Msizi Public Librar y forms par t of the municipal precinct of buildings situated along Keet Street in Kareedouw, Eastern Cape. The building consists of two parts: the public librar y with accompanying administrative and ser vice areas, and a small public conference component with ablutions.

Debbie Wintermeyer, architect, The Workplace Agency, explains that the design of the Mcebisi Michael Msizi Public Librar y ensured the approximately 650 m² building remained modest in scale and expression, while still maintaining integrity and status as an important municipal building.

“We wanted to create a community precinct for Mcebisi Michael Msizi with facilities located off an open foyer area, that was simple to use, multifunctional and crafted in response to the beautiful natural surroundings. We also incorporated a small courtyard and front arrival foyer into the plans as a way to increase usable spaces.”

Material of choice The librar y makes use of Corobrik’s Firelight Satin face brick, which Wintermeyer says was chosen for its consistent colour and shape and used with the red-tinted flush joints, gave a slick, sheer appearance on completion.

“The Firelight Satin face brick was used inside and out the librar y, with minimal brick detailing in the form of roller-course lintels, bullnose brick coping at the top of walls and squint bricks at the window reveals. We are particularly proud of the face brick buttress wall with its clerestor y lighting over the top and the buttresses with bookshelves in between.”

The librar y’s interior main space was constructed in a variety of scales, ranging from the large face brick buttressed back wall and clerestor y windows, to the low, intimate study nooks and children’s section in the north. The material palette was kept to a minimum, with expressed steel frame and the face bricks the primaries in the rugged framework.

“The Mcebisi Michael Msizi Public Librar y is another captivating example of what can be achieved when using quality products and an innovative design,” says Musa Shangase, commercial director at Corobrik.

“This Eastern Cape community will benefit from the town’s first dedicated, modern librar y building, which has been constructed to maximise on the natural temperature regulators while working into the surrounding aesthetic. The inclusion of Corobrik’s durable face brick range means that generations to come will get to enjoy full use of this facility.”

The librar y – which is a recipient of the SAIA-EC Regional Commendation – was funded by the Eastern Cape’s Department of Sports, Recreation, Arts and Culture and Public Works and opened to the public this year. Shangase believes the longstanding par tnership between Corobrik and government has resulted in many iconic buildings, such as this, which were enhancing the lives of South Africans ever ywhere.

ABOVE & BELOW The Mcebisi Michael Msizi Public Library in Kareedouw is the community’s first dedicated, modern library building (Credit: David Dettman)

IMIESA January 2020

53

INDUSTRY NEWS

Semane welcomes new CEO Engineering solutions provider Semane, which was spun off by Anglo American in 1998, has appointed Muzi Siyaya as its new CEO. Muzi Siyaya, new CEO of Semane

M A STRONG FOUNDATION FOR INFRASTRUCTURE SUCCESS ROCLA is South Africa’s leading manufacturer of pre-cast concrete products.

Surpassing 100 years of product excellence.

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uzi Siyaya holds an MBA from Wits University and joins Semane after spending six years at GIBB Engineering as group executive responsible for business development and strategy. Siyaya has more than 20 years’ experience, having previously held senior management and executive roles at MTN, Cell C and Dimension Data subsidiary Plessey.

“The board believes Muzi’s multifaceted experience will direct Semane into a new trajectory. He has broad business skills and experience in managing growth in a rapidly evolving business landscape,” says executive chairman Joel Mokgohlwa.

Siyaya is taking over from founding CEO Joe Araujo, who is retiring from the company after 21 years at the helm and will continue in a consulting capacity. On behalf of the company and its stakeholders, Mokgohlwa extends the board’s profound gratitude and appreciation to Araujo for his impeccable service and leadership, which have seen Semane grow to its current market position as a respected engineering solutions consultancy, delivering sought-after expertise and experience.

Semane boasts clients such as Anglo American, Foskor, Exxaro, Rio Tinto, Seriti, BHP and Gold Fields.

“I was attracted to Semane because it is a well-managed business that has stability, an enviable track record, a good culture and a great team. The framework for good governance that was laid by Anglo American 21 years ago is evident in the business today,” says Siyaya.

“Semane is a company poised for its next growth trajectory.

From that standpoint, I feel I can make a difference. I look forward to getting to know the people at Semane, our clients and partners.”

ENERGY

Run-of-river power

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wned by a special purpose vehicle, Butama Hydro Electricity Company, Sindila is a high-head run-of-river plant with a total gross head of 402 m driving two 2.8 MW pelton turbines. The project represents an investment of US$20 million (R295.8 million) into the Uganda power sector and created well over 500 jobs at peak employment – the majority of which went to workers from the local community.

Metier, via its Lereko Metier Sustainable Capital (LMSC) fund, is the majority investor.

Minority shareholders alongside Metier are: KMRI, the original project developers; Fieldstone Africa Investment Resources (FAIR); and WK Power. FAIR, a development support arm of Fieldstone, provided development funding alongside LMSC, as well as active development support.

WK Power, a wholly owned subsidiary of South Africa-based company WK Construction, was the civil engineering procurement and

Community benefits

construction contractor. WK Power is also the operator via its Ugandan entity, Sindila Hydro Construction.

The project is funded by a combination of debt and equity, with debt provided by the Overseas Private Investment Corporation. The project development was also supported by the UNEP Seed Capital Assistance Facility.

The Ugandan and South African offices of SMEC provided owner’s engineer and project management services; Aurecon acted as the lender’s independent engineer; and Synergy Global Consulting provided social and environmental management support during construction.

SMEC deployed a Ugandan resident engineer supported by a technical review team based in Nairobi, Kenya, and a project management team operating out of Johannesburg. This blend of resources provided cost-effective support to Butama Hydro Electricity Company, epitomising SMEC’s motto of ‘local people, global experience’.

The project has also implemented a range of socio-economic development projects in the area. The local economy is based on subsistence and cash farming. Local households have no formal infrastructure services. Project initiatives include a standpipe water reticulation system for households who previously had to collect water from the river, a bean planting programme and other agricultural support, and a planned solar-homes programme to provide electricity to households in the vicinity of the plant.

Since April 2019, operations have been slightly hampered by an unstable grid connection; however, the project is working closely with UETCL and the Rural Electrification Agency of Uganda, which are in the process of implementing a major grid strengthening programme between the project site and Fort Portal, the nearest major town. This will improve the stability of power evacuation.

Going forward, the project will generate approximately 28 GWh of electricity per year, which will be purchased by UETCL under a 20-year power purchase agreement.

INDEX TO ADVERTISERS

AmanziFlow

41

IMESA

ASPASA

46

JPCE

2, 4, 56 49 IFC

Rocla

54

SAPPMA

19

Sika

37

Circuit Water Engineering

OBC

Lafarge

Drakenstein Municipality

OFC

Macsteel

20

Sizabantu Piping Systems

IBC

ELB Equipment (Hammerhead)

50

Mamba Cement

45

South African Bitumen Association

28

Franki

14

Mather+Platt

31

The Water Show

32

Geo Group

13

Much Asphalt

27

Wirtgen

11

IMIESA January 2020

55

I M E S A A F F I L I AT E M E M B E R S

IMESA

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