IMIESA September 2022

www.infrastructurenews.co.za

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

INFRASTRUCTURE DEVELOPMENT • SERVICE DELIVERY • ROADS • BUILDING • MAINTENANCE • ENERGY

Trenchless Technology

Sewer network inspection and maintenance

Pipe Systems

The exciting evolution of plastic pipe

Water & Wastewater

Blue Drop and No Drop audits underway

M&D Construction Experts in water infrastructure

IN THE HOT SEAT Quality is non-negotiable and we use the best technology available to ensure we supply our customers with world-class products made in South Africa.”

Christo Le Grange Quality Manager, Hall Longmore I S S N 0 2 5 7 1 9 7 8 Vo l u m e 4 7 N o . 0 1 • J a n u a r y 2 0 2 2 • R 5 5 . 0 0 ( i n c l . VAT ) I S S N 0 2 5 7 1 9 7 8 Vo l u m e 4 7 N o . 0 9 • S e p t e m b e r 2 0 2 2 • R 5 5 . 0 0 ( i n c l . VAT )

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INSIDE

VOLUME 47 NO. 09 SEPTEMBER 2022

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28 www.infrastructurenews.co.za

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

INFRASTRUCTURE DEVELOPMENT • SERVICE DELIVERY • ROADS • BUILDING • MAINTENANCE • ENERGY

Trenchless Technology

Sewer network inspection and maintenance

Pipe Systems

The exciting evolution of plastic pipe

Water & Wastewater

Blue Drop and No Drop audits underway

M&D Construction Experts in water infrastructure

Regulars

SAPPMA

Editor’s comment President’s comment Index to advertisers

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6

Infrastructure news from around the continent

I S S N 0 2 5 7 1 9 7 8 Vo l u m e 4 7 N o . 0 1 • J a n u a r y 2 0 2 2 • R 5 5 . 0 0 ( i n c l . VAT ) I S S N 0 2 5 7 1 9 7 8 Vo l u m e 4 7 N o . 0 9 • S e p t e m b e r 2 0 2 2 • R 5 5 . 0 0 ( i n c l . VAT )

ON THE COVER M&D Construction Group, a leading multidisciplinary construction company, has earned a solid reputation for its ability to build world-class water supply infrastructure. This includes state-of-the-art water and wastewater treatment plants, as well as reservoirs and water towers. P6

IN THE HOT SEAT Hall Longmore’s growth over close to 10 decades is the result of a concerted focus on product innovation, backed by best-in-class steel pipe manufacturing techniques.

IMIESA speaks to quality manager Christo Le Grange about the company’s latest investment in automated radiographic testing technology at its Duncanville factory.

P10

16

TRENCHLESS TECHNOLOGY

8

Vehicles & Equipment

12

Information & Communications Technology Connecting Africa to the internet by land and sea

14

Blue Drop and No Drop audits are underway The Ozone and UV Revolution

16

Concrete Retaining Block Systems

18

New 4x4 Step Block caps add a clean finish

Precast Pipes, Culverts & Stormwater Moulded by design: the versatility of precast systems

22

24

Pipelines Twin-Wall pipe reintroduced to the South African market

22

PRECAST PIPES, CULVERTS & STORMWATER

40 41

42 45

46

Cement & Concrete

Inner-city Renewal The Onyx: engineered for the future

A new all-rounder in the heavy-duty truck class ELB awarded GEHL partner dealer status

Water & Wastewater

Trenchless Technology The Rolkon Way Healthy pipelines essential for sustainable living conditions

Roads & Bridges

10

Asset Management Improving asset management capacity within municipalities

37

Roads and economics are interlinked 38 Promoting the use of waste in road construction 39

Hot Seat Switching over from analogue to digital radiographic pipe inspection

34

Instrumentation Customised IoT pressure management solutions

Africa Round-up

Quality is non-negotiable and we use the best technology available to ensure we supply our customers with world-class products made in South Africa.”

Christo Le Grange Quality Manager, Hall Longmore

Soil Mechanics Bedding, embedment, backfill and compaction

Cover Story M&D always ‘finds the best way’ to build water infrastructure

IN THE HOT SEAT

The exciting evolution of plastic pipe 28

Prompt attention to spalled joints helps prevent costly repairs Making construction attractive to the youth Kariba sluice gates rehabilitation ongoing

48 49 51

Electrification 26

Upgrading electricity services in KwaDukuza Local Municipality

46

CONCRETE RETAINING BLOCK SYSTEMS

52

Save the date 25-27 October 2023

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EDITOR’S COMMENT MANAGING EDITOR Alastair Currie SENIOR JOURNALIST Kirsten Kelly JOURNALIST Nombulelo Manyana EDITORIAL COORDINATOR Ziyanda Majodina HEAD OF DESIGN Beren Bauermeister DESIGNER Lizette Jonker CHIEF SUB-EDITOR Tristan Snijders CONTRIBUTORS Pieter Crous, Alaster Goyns, Chetan Mistry, Stewart Russell, Mike Smart, Bhavna Soni PRODUCTION & CLIENT LIAISON MANAGER Antois-Leigh Nepgen GROUP SALES MANAGER Chilomia Van Wijk BOOKKEEPER Tonya Hebenton DISTRIBUTION MANAGER Nomsa Masina DISTRIBUTION COORDINATOR Asha Pursotham SUBSCRIPTIONS subs@3smedia.co.za ___________________________________________________ ADVERTISING SALES KEY ACCOUNT MANAGER Joanne Lawrie Tel: +27 (0)11 233 2600 / +27 (0)82 346 5338 Email: joanne@3smedia.co.za ___________________________________________________

PUBLISHER Jacques Breytenbach 3S Media Production Park, 83 Heidelberg Road, City Deep Johannesburg South, 2136 PO Box 92026, Norwood 2117 Tel: +27 (0)11 233 2600 www.3smedia.co.za ANNUAL SUBSCRIPTION: R600.00 (INCL VAT) ISSN 0257 1978 IMIESA, Inst.MUNIC. ENG. S. AFR. © Copyright 2022. All rights reserved. ___________________________________________________ IMESA CONTACTS HEAD OFFICE: Manager: Ingrid Botton P.O. Box 2190, Westville, 3630 Tel: +27 (0)31 266 3263 Email: admin@imesa.org.za Website: www.imesa.org.za BORDER Secretary: Celeste Vosloo Tel: +27 (0)43 705 2433 Email: celestev@buffalocity.gov.za EASTERN CAPE Secretary: Susan Canestra Tel: +27 (0)41 585 4142 ext. 7 Email: imesaec@imesa.org.za KWAZULU-NATAL Secretary: Narisha Sogan Tel: +27 (0)31 266 3263 Email: imesakzn@imesa.org.za NORTHERN PROVINCES Secretary: Ollah Mthembu Tel: +27 (0)82 823 7104 Email: np@imesa.org.za SOUTHERN CAPE KAROO Secretary: Henrietta Olivier Tel: +27 (0)79 390 7536 Email: imesasck@imesa.org.za WESTERN CAPE Secretary: Michelle Ackerman Tel: +27 (0)21 444 7114 Email: imesawc@imesa.org.za

Rallying behind SOUTH AFRICA

T

his year has been one of the worst on record for Eskom power outages, and predictably it had a negative impact on South Africa’s Q2 2022 GDP performance within the context of a highly volatile international commodities market. The upside is that while South Africa’s Q2 GDP figures are down by around 0.7%, there was a sustained upward trend in the previous two consecutive quarters.

Moving forward, global supply chain constraints will continue to be affected for the foreseeable future as the Russia-Ukraine conflict continues.

The higher cost of international borrowing also presents challenges at a time when the South African government has stated its commitment to progressively lowering the public debt burden.

Managing inflationary pressures To curb inflation, and smooth out the peaks and troughs in the domestic market, the Monetary Policy Committee of the South African Reserve Bank (SARB) took the decision to opt for a further interest rate hike in September 2022. As Dr Rashad Cassim, deputy governor, SARB, stated, “Our objective is to look past the immediate supply shock, focus on the period after it has subsided, and ensure inflation stabilises at that point.” The ultimate objective is “moving towards a more balanced or neutral interest rate setting.”

While higher interest rates do burden borrowers, the current 9.75% lending rate is still favourable when you consider that it peaked at around 17% back in 2003. Higher interest rates also attract money market investors and promote a muchneeded savings culture in South Africa that reduces social dependence on the state.

A macroeconomic policy that works The key to repositioning for sustained growth is a sound macroeconomic framework that is conducive to attracting both foreign and domestic investors.

FREE STATE & NORTHERN CAPE Secretary: Wilma Van Der Walt Tel: +27 (0)83 457 4362 Email: imesafsnc@imesa.org.za All material herein IMIESA is copyright protected and may not be reproduced without the prior written permission of the publisher. The views of the authors do not necessarily reflect those of the Institute of Municipal Engineering of Southern Africa or the publishers. _____________________________________________

Put the right skills in place Allied to this is the pressing need to address engineering and financial skills deficits in the municipal and SOE environment that contribute towards poor asset management and reactive maintenance interventions.

Bringing back the role of the traditional town engineer – universal in countries like the UK – with oversight for infrastructure project preparation, programme management and execution, would make an immediate and positive difference. Plus, there is no shortage of experienced and qualified candidates from the private sector who would be willing to step forward and do their civic duty.

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

www.infrastructurenews.co.za

IMESA

@infrastructure4

Infrastructure News

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

INFRASTRUCTURE DEVELOPMENT • SERVICE DELIVERY • ROADS • BUILDING • MAINTENANCE • ENERGY

Trenchless Technology

Sewer network inspection and maintenance

Pipe Systems

The exciting evolution of plastic pipe

Water & Wastewater

Blue Drop and No Drop audits underway

M&D Construction Experts in water infrastructure

Novus Holdings is a Level 2 BBBEE Contributor: novus.holdings/sustainability/transformation

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

Rather than imposing prescribed assets legislation, for example, a focus on ease of doing business and policy certainty would encourage the local pension industry to step forward voluntarily in support of South Africa’s Infrastructure Fund.

Before that, we need an urgent revamp of major impediments that include current public-private partnership (PPP) legislation. We also need to put forward a far greater array of bankable projects to mobilise available funding and provide a constant pipeline of work for our construction industry – one of our most vital and enabling assets.

At present, the construction sector is 24% smaller than it was before Covid-19 hit but, as with the FIFA 2010 World Cup, that can change ‘overnight’ with optimal PPP implementation. Alongside renewable energy projects – of which the larger ones can take three years or more to build and commission – we need immediate investments in roads, water and wastewater, and social housing.

IN THE HOT SEAT Quality is non-negotiable and we use the best technology available to ensure we supply our customers with world-class products made in South Africa.”

Christo Le Grange Quality Manager, Hall Longmore I S S N 0 2 5 7 1 9 7 8 Vo l u m e 4 7 N o . 0 1 • J a n u a r y 2 0 2 2 • R 5 5 . 0 0 ( i n c l . VAT ) I S S N 0 2 5 7 1 9 7 8 Vo l u m e 4 7 N o . 0 9 • S e p t e m b e r 2 0 2 2 • R 5 5 . 0 0 ( i n c l . VAT )

Cover opportunity

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

IMIESA September 2022

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Call for ABSTRACTS

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PRESIDENT’S COMMENT

IMESA

Final countdown to the

85TH ANNUAL IMESA CONFERENCE We are now weeks away from our 85th IMESA Conference, an annual event that brings together industry experts from across South Africa and the globe.

T

his year’s conference, themed ’Adapting to our Changing World’, takes place in Boksburg at the Birchwood Hotel and O.R. Tambo Conference Centre (Birchwood) between 2 and 4 November – and for those that haven’t registered, there’s still time.

With this being our first in-person conference since 2019, it is a pleasure at last to be able to offer our traditional format where delegates can look for ward to an excellent range of presentations, networking opportunities, as well as engagement with a diverse array of exhibitors fielding innovative products and solutions. There will also be a knowledge bar where delegates can listen to short presentations during the breaks and speak directly to the presenters.

Good spread of municipalities attending Based on confirmed registrations so far, it’s ver y encouraging to see the growing number of delegates representing local and district municipalities, many of whom will be attending for the first time. The conference is endorsed by the South African Local Government Association (Salga), and we value their involvement as a strategic alliance partner in expanding IMESA’s membership base, as well as our mandate of promoting excellence in municipal engineering.

In addition to Salga, representation from Consulting Engineers South Africa (CESA), National Treasur y and the Engineering Council of South Africa (ECSA) will enable

proactive debate on key issues. These include the importance of professional registration, addressing gaps in engineering skills within municipalities, as well as the best ways to alleviate procurement and tender bottlenecks.

International perspective Adding an international perspective, David Jenkins, CEO of the Institute of Public Works Engineering Australasia (IPWEA), is our keynote speaker and will share his insights on infrastructure asset management – a top priority in any municipal environment worldwide.

Along with IMESA, and allied associations globally, IPWEA is a member of the International Federation of Municipal Engineering (IFME). The latter will be sending a delegation to the conference, headed by Sanne Hieltjes, president of IFME, from the Netherlands.

Water reclamation and reuse workshop Ahead of the 85th IMESA Conference, we’ll be hosting a separate one-day workshop at Birchwood on 1 November 2022. This workshop will explore the best practice application of the recently released document entitled, A Water Reclamation and Reuse Guide for South African Municipal Engineers.

This guide was officially launched by the Water Research Commission (WRC) on 1 September 2022 and is a collaborative effort led by the WRC in conjunction with IMESA, as well as stakeholders represented by the Water Institute of Southern Africa.

Bhavna Soni, president, IMESA

Given South Africa’s increased frequency of devastating droughts, plus surging population growth, it’s clear that water security is a pressing concern going for ward in what is already a water-scarce countr y. Wastewater reuse is a widely accepted practice in both developed and developing nations that include Singapore and Namibia.

For this reason, reuse has been identified as one of the most viable strategies in South Africa to augment drinking water supply. So far, however, there’s been limited success in implementing reuse projects within the local municipal environment, hence the need for a series of capacitybuilding workshops. For further information on the 1 November workshop at Birchwood, email technical@imesa.org.za or visit www.imesa.org.za.

In the meantime, I would like to extend my thanks to the organising committee, our sponsors, exhibitors and delegates for their participation in what is certain to be a rewarding and memorable 85th IMESA Conference. I’ll see you there!

IMIESA September 2022

5

COVER STORY

M&D always ‘finds the best way’ TO BUILD WATER INFRASTRUCTURE M&D Construction Group (M&D), a leading multidisciplinary construction company, has earned a solid reputation for its ability to build world-class water supply infrastructure. This includes state-of-the-art water and wastewater treatment plants, as well as reservoirs and water towers.

O

ver the past six years, M&D’s Civils and Infrastructure Division has successfully delivered 10 reservoirs and two water towers of various sizes. The company has undertaken these projects on behalf of leading local municipalities and water authorities. They include Magalies Water, Umgeni Water, Johannesburg Water, City of Ekurhuleni, and Breede River Municipality.

This is in addition to two private sector client bodies, namely Heineken and Impala Platinum.

Reservoirs and water towers are very complex structures to construct, relying on specialist skills, experiences and capacities.

They involve the design and application of highspecification water-retaining concrete mixes.

Moreover, this technical excellence often needs to be deployed effectively in very remote areas where many of these structures are built. This presents numerous logistical challenges that necessitate careful upfront planning to ensure that the construction programme proceeds as planned.

Moreover, contractors need to be able to work well with communities located within the project footprint. This is to maximise community participation in these projects while also ensuring that local small, medium and micro enterprises (SMMEs) are able to maintain high-quality workmanship in line with that of the principal contractor. There is very little scope for error when constructing

6 IMIESA September 2022

Valued at more than R52 million, this 15 Mℓ post-tensioned reservoir has a wall height of 8.5 m and a circumference of 157 m

water-retaining structures, leading to costly delays.

with

mistakes

The spirit of Kula Nathi M&D has consistently excelled on these projects, which have always provided the perfect opportunity for the company to showcase its core values. These are also M&D’s key differentiators in the water infrastructure market. They include ‘be safe’, ‘do what you say’, ‘find the best way’ and ‘do it right’. This is in addition to Kula Nathi – isiZulu for ‘grow with us’.

Kula Nathi has enabled M&D to grow and develop a multi-skilled team that is needed to execute these projects ver y efficiently. Importantly, this team also comprises seasoned site managers and super visors who have played a key role in successfully delivering this infrastructure.

Moreover, Kula Nathi has enabled the company to nurture strong professional relationships with subcontractors and suppliers with an impressive track record in water infrastructure. Certainly, the spirit of Kula Nathi is also applied when working with SMMEs and community members on these projects.

Lenasia on behalf of Johannesburg Water. The company worked alongside Nyeleti Consulting, which was the design engineer and supervised the construction programme.

Niekie Wagener, head: Civils and Infrastructure, M&D, says that the project was a resounding success. He credits Nyeleti Consulting for having played a large role in the very positive outcome. “This was certainly one of the best reservoir engineering designs M&D has had the opportunity to implement thus far. It was extremely well designed in terms of constructability. Certainly, the very strong team of engineers that Nyeleti Consulting deployed to the project also facilitated the efficient construction of this infrastructure.

Furthermore, team dynamics between client, engineer and contractor were again very positive, creating an environment that was conducive to high levels of productivity and efficiency,” Wagener says.

This 15 Mℓ post-tensioned reservoir has a wall height of 8.5 m and a circumference of 157 m. Valued at more than R52 million, the new reservoir has brought an end to water supply interruptions in Lenasia and surrounding areas, which have been growing at a tremendous rate, placing significant pressure on existing water supply infrastructure.

Lenasia reservoir development showcases excellence

Opportunities for innovation

M&D recently deployed these extensive skills and capabilities to construct a reservoir in

The project again provided M&D with an opportunity to innovate. The wall formwork

On these projects, contractors need to be able to work well with communities located within the project footprint

The new infrastructure has brought an end to water supply interruptions in Lenasia and surrounding areas

M&D Construction Group, a leading multidisciplinary construction company, has earned a solid reputation for its ability to build world-class water supply infrastructure

was designed to be undertaken in a single 8.5 m lift – the first time a reservoir has been constructed in this manner in the country.

It was so designed by M&D to minimise construction joints in the wall, which was in line with Nyeleti Consulting’s design philosophy. By minimising the need for joint bandages, maintenance requirements have been significantly reduced over the entire life cycle of the infrastructure. Considering the substantial long-term cost saving it will provide Johannesburg Water, the solution was very favourably received by the client.

However, constructing the reservoir wall in this manner was a steep learning curve for M&D and Nyeleti Consulting. A major challenge was the very thin reservoir wall, with the post-tensioning sleeves inside the formwork restricting space through which the concrete needed to flow. To prevent honeycombing, the

concrete mix was designed specifically for this application. Windows were also incorporated into the formwork design and experimental sleeves used to increase the space in which to vibrate the concrete.

Rukesh Raghubir, CEO of M&D, says that he is very impressed with the outcome. “I consider this project to be one of our many flagships, in terms of water-retaining structures. It demonstrates why we have remained a leader in the water infrastructure market.

“Our team that was deployed to site was able to ‘find the best way’, ‘do what we say’, ‘do it right’ and, importantly, ‘be safe’. Our spirit of Kula Nathi also prevailed throughout the project when working with subcontractors and suppliers, as well as SMMEs and community members. This also supported Johannesburg Water’s focus on ensuring that its infrastructure projects always

start benefiting constituents as early as the construction phases,” Raghubir explains.

“The project met our client’s expectations in this regard by creating jobs, as well as training and development opportunities. We also delivered a world-class reservoir that will help to provide a reliable supply of water to residents of Lenasia and surrounding areas, and that will continue to add value over its entire life cycle,” Raghubir concludes. www.mdconstruction.co.za

IMIESA September 2022

7

INFRASTRUCTURE NEWS

FROM AROUND THE CONTINENT

RWANDA Steady growth in electric mobility In an effor t to encourage electric mobility, the Rwandan government has implemented the following measures: • reduced electricity tariffs • spare par ts, charging station equipment and batteries are VAT zero rated products and are exempt from cer tain impor t and excise duties • an exemption of a 5% of withholding tax at customs • rent-free land for charging stations • free licence and authorisation for commercial EVs • 15% corporate income tax and a tax holiday for manufacturing and assembly firms.

There is now a growing fleet of electric vehicles in the capital, with the government considering electric buses to fur ther cut carbon emissions.

Just recently, a star t-up named OX Delivers introduced electric trucks that can glide through dir t roads and deliver har vest from farmers to markets, airpollution-free. Victoria Motors has also taken advantage of these incentives.

“At inception, we anticipated a slow but steady growth of the electric mobility market in Rwanda. We have, however, been surprised by the uptake of our e-mobility transpor t solutions, par ticularly after the passing of the government incentives late last year. These in a way have made the vehicles more affordable to the Rwandan market,” says Joshua Nshuti, innovations and business development manager, Victoria Motors.

“However, it is not enough to make a decision to acquire a brand-new vehicle based purely on initial cost but rather the initial cost coupled with maintenance and operational costs over the life of the vehicle. Once this approach is taken into consideration, electric vehicles always prove better value for money before even considering the comfor t, safety features and modern driving experience they offer,” he adds.

GHANA $133 million investment in water

supply infrastructure

ETHIOPIA GERD: Second turbine begins producing power The Great Ethiopian Renaissance Dam (GERD), set to be Africa’s largest hydroelectric scheme, has kick-star ted electricity production from its second turbine. Ethiopia first began generating electricity at the dam in Februar y 2022.

Currently, the two turbines, out of a total of 13 at the dam, have a capacity to generate 750 MW of electricity.

The dam is in the Benishangul-Gumuz Region of Ethiopia. Its primar y purpose is electricity production to relieve Ethiopia’s acute energy shor tage and for electricity expor t to neighbouring countries. Filling the reser voir began in July 2020. It will take between four and seven years to fill with water, depending on hydrologic conditions during the filling period.

The potential impacts of the dam have been the source of significant regional controversy. Egypt, a countr y that relies heavily on the waters of the Nile, has demanded that Ethiopia cease construction on the dam as a precondition to negotiations and has sought regional suppor t for its position. Ethiopia denies that the dam will have a negative impact on downstream water flows and contends that the dam will, in fact, increase water flows to Egypt by reducing evaporation on Lake Nasser.

8 IMIESA September 2022

The Bono Region authority and Ghana Water Company Limited (GWCL) are par tnering to improve water supply in Sunyani through a $133 million (R2.24 billion) investment.

Bono Regional Minister Justina Owusu-Banahene recently visited the construction of a new water supply facility at Abesim, close to Sunyani, along with Samuel Ason, chief engineer for GWCL in Bono.

A water intake that will feed a drinking water plant with a daily capacity of 55 000 m3 will be constructed as par t of the project.

Furthermore, elevated and groundlevel tanks with a combined capacity of about 16 500 m3 will be included in the future facilities. In addition, 10 000 household meters will be installed as part of the project to improve the water supply in Sunyani, along with the construction of two booster stations, 93 km of transmission pipelines, buildings to house laboratories and chemical storage, and a power line to serve the entire region.

TRENCHLESS TECHNOLOGY | SEWER REHABILITATION COVER STORY

KENYA Water supply system in Naivasha Industrial Park The system, inaugurated by President Uhuru Kenyatta of Kenya, will supply water to the Inland Container Depot (ICD) and the Special Economic Zone (SEZ).

Rift Valley Water Works Development Agency, appointed by the Kenyan government, carried out all the work. The development project required a US$8.42 million (R139 million) investment and involved the construction of five large boreholes, the laying of pipes, storage tanks, the installation of pumps, and the construction of kiosks to supply the local communities.

In addition to water supply, the project improves wastewater management in the Naivasha SEZ and ICD, including reticulation and effluent disposal systems.

With deliver y of the future facility beginning in 2025, ear thworks are anticipated to begin towards the end of July 2022. GWCL currently supplies residents in Sunyani town through groundwater pumping stations. By storing rainwater, the utility hopes to ease pressure on the water table.

NAMIBIA First Bitcoin ATM goes live

The first Bitcoin ATM in Namibia is now operational at Maerua Mall in Windhoek via the Cr ypto Kiosk.

Operating in full compliance with the Namibian Financial Intelligence Centre, the Cr ypto Kiosk requests cer tain information from the user before transacting, such as Namibian ID number, postal address and a selfie of the client. Additionally, if a client is transacting more than N$5 000 (R5 530), they will need to submit their residential address and a copy of the identity document to comply with current regulator y policies.

Users of the Cr ypto Kiosk can buy or sell Bitcoin and Ethereum, two of the biggest cr yptocurrencies.

A Bitcoin ATM can liquidate cr yptocurrency into cash directly from cr ypto wallets, and turn cash into cr yptocurrency, sent directly to cr ypto wallets. Bitcoin ATMs look like traditional ATMs but do not connect to a bank account, and instead connect directly to a cr ypto exchange or private wallet.

There are currently 38 317 Bitcoin ATMs located in 77 different countries.

IMIESA September 2022

9

HOT SEAT

A technician manning the new digital RT operator station.

The three control screens (from left) show a live view of the pipe in the test bay, enabling the operator to perform a visual inspection for potential weld defects; the middle screen shows the X-ray image; and the third screen is the reporting system

SWITCHING OVER FROM

ANALOGUE TO DIGITAL radiographic pipe inspection Hall Longmore’s growth over close to 10 decades is the result of a concerted focus on product innovation, backed by best-in-class steel pipe manufacturing techniques. IMIESA speaks to quality manager Christo Le Grange about the company’s latest investment in automated radiographic testing (RT) technology at its Duncanville factory.

Christo Le Grange, quality control manager, Hall Longmore

What is Hall Longmore’s current production focus and capabilities?

CLG Hall Longmore has two factories in South Africa, namely our Duncanville plant in Vereeniging, and the Wadeville facility in Germiston. Combined, these plants have the potential to produce around 230 000 tonnes of steel pipe annually.

These state-of-the-art manufacturing facilities feature the most modern pipemaking equipment, as well as specialist coating and lining application processes.

Our two main products are electric resistance welded (ERW) pipe and spiral welded steel pipe employing the submerged arc-welding (SAW) process. ERW pipe is manufactured in Wadeville for the oil and gas markets, as well as the water sector, with a strong export focus. In turn, our Duncanville factory specialises in the production of SAW products, with around 98% of our production serving the bulk water infrastructure market locally and in Africa.

10 IMIESA September 2022

Which pipe specifications are produced at Duncanville?

At Duncanville, we produce SAW pipes up to a maximum length of 19.2 m. Depending on the requirement, diameters range from DN500 to DN2 400 and wall thicknesses from 6 mm up to 20 mm.

What are the key quality control systems in place?

In line with international standards, steel pipe manufacturers globally are required to employ RT technology to performing non-destructive testing (NDT) on each welded pipe section as it comes off the production line. Inspection and fault detection are performed via a specialist fluoroscopic X-ray machine designed for industrial applications.

However, before each pipe reaches the X-ray test bay, there are a series of quality control steps required. For SAW pipe, the first requirement is the correct setup of the steel coil feed to ensure a sound and proper weld in line with specific codes and specifications.

Is RT a compulsory requirement?

RT is a mandatory requirement for SAW pipe in terms of the American Petroleum Institute standards, as is ultrasonic testing for ERW pipe. Locally, RT is also a supplementary requirement stipulated by water utilities for SAW pipe, in addition to hydrostatic pressure testing.

When was the first RT system installed and why opt for an upgraded unit?

Our first RT facility was installed at the Duncanville plant around 1994 and has been in daily use since then. It was cutting-edge technology at the time, back in the days when analogue X-ray systems were the norm.

In the ensuing decades, however, the rise of digital electronic technologies has made analogue obsolete.

While our analogue RT unit has stood the test of time, it was clear that we needed to move into the digital world sooner rather than later and to provide our factory technicians with the

current technology; with digital RT, inspection times will drop dramatically.

Being digital, the latest RT systems are designed to integrate into the plant’s IT infrastructure. In the past, X-ray test parameters needed to be inputted manually within the analogue environment. However, thanks to digital RT, the process is now almost 100% automated, which makes it far more accurate in terms of defect detectability. All the operator needs to do is type in the unique pipe ID and the system takes care of the rest.

Who supplied the digital RT system and how much did it cost?

All the components for our new inline RT system have been sourced from Balteau, a leading OEM based in Belgium. Locally, the supply and commissioning of this custom solution has been carried out by NDT specialist H. Rohloff, and the overall project cost is estimated at around R5 million.

To protect against radiation, strict safety protocols have been implemented. The operator control room is shielded from the X-ray inspection bay by a specially designed steel door that if opened accidently, automatically shuts everything down immediately.

To the best of our knowledge, this is the first digital RT system installed to date within the South Africa steel pipe manufacturing industry and it is capable of X-raying up to a 40 mm pipe wall thickness. The system has taken around five months to install and commission.

The SAW pipe mill at our Wadeville factory currently has a similar analogue X-ray device to the one now decommissioned in Duncanville.

So, once we’ve optimised the new system here, our next project will be to transition Wadeville to digital RT.

How different is analogue versus digital RT technology?

There is a massive technology gain. Ten times faster inspection speeds are now possible without sacrificing quality of testing.

The RT system incorporates an uninterrupted power supply backup system, which provides added assurance during load-shedding

Hall Longmore’s new digital RT system undergoing commissioning trials in the X-ray test bay at the Duncanville factory

An overview of the RT setup

Additionally, the process is more accurate, fully computerised and delivers enhanced traceability. This time constraint liberation leads to increased quality throughput and costeffective manufacturing.

The operator station on the new system has three screens. The first shows a live view of the pipe in the test bay, enabling the operator to perform a visual inspection for potential weld defects; the middle screen shows the X-ray image; and the third screen is the reporting system.

Information is recorded as raw data in exhaustive detail. This means that at any time – even 10 years later on a possible pipe failure dispute – all the data can be recalled and re-analysed as if you were X-raying the pipe for the first time. That’s in comparison to analogue, where the report only records the once-off findings of the inspector.

We’re proud to say that, even with the old analogue system, we’ve been consistently below this threshold.

And in closing?

At Hall Longmore, we strive to be in line with modern and up-to-date inspection and testing solutions, which not only meet but exceed local and international standards.

Quality is non-negotiable and we use the best technology available to ensure we supply our customers with world-class products made in South Africa.

KEY BENEFITS OF DIGITAL RT COMPARED TO ANALOGUE • Increased defect detectability due to higher sensitivity • Significantly lower background noise with digital filtering

Will digital RT make you see things differently?

• Contrast adjustability for fine defect detection

Over time, digital RT will help us pinpoint further quality improvements that will take Hall Longmore’s reputation for product excellence to new heights due to enhanced weld defect detection. The continuous feedback loop from the digital RT team to the production setup team will also lead to a much higher rate of first-time passes.

Internationally, the accepted norm for pipes that fail the RT test – in other words, where weld defects are detected – is less than 3%, which is also Hall Longmore’s quality target.

• Lower X-ray radiation energy due to enhanced image detectors that require less energy • Fixed X-ray energy for multiple thicknesses due to adjustable contrast settings. (With analogue, varied X-ray energy is required for different thicknesses) • 10 times faster inspection speeds are now possible without sacrificing quality of testing • Instant result storage and reporting • X-ray results are immediately available and transferrable • Automated spraying unit to ID and mark defects

www.hall-longmore.co.za

IMIESA September 2022

11

ASSET MANAGEMENT

IMPROVING ASSET MANAGEMENT CAPACITY

within municipalities

Sound asset management practices are critical for good governance, transparency and accountability to facilitate investment for sustainable service delivery. However, the process can be complex and requires an expert understanding to implement.

By Stewart Russell and Dr Pieter Crous, SMEC South Africa

Dr Pieter Crous

Stewart Russell

A

sset management has typically been championed within municipalities under the office of the CFO or units within finance departments. However, asset management reaches across departments and requires both financial and technical expertise to compile a compliant and appropriate asset register.

Legislation entrenched in the Integrated Development Plan (IDP), as a strategic planning mechanism for municipalities, indicates that Infrastructure Asset Management Plans (IAMPS) be developed as input for the Comprehensive Municipal Infrastructure Plan (CMIP). The CMIP presents an integrated plan across all sectors/asset portfolios. As such, an overarching legislative requirement is established for the appropriate management of public infrastructure, which is enshrined through our Constitution.

12 IMIESA September 2022

From an accounting perspective, the Municipal Finance Management Act (No. 56 of 2003; MFMA) requires municipalities to comply with standards of Generally Recognised Accounting Practices (GRAP). In addition to GRAP, mSCOA (Municipal Standard Chart of Accounts) sets out to achieve an acceptable level of uniformity and quality to facilitate effective budgeting and expenditure of assets. The motivation for municipalities to adhere to the mSCOA framework includes: • data integrity and credibility • inter- and intra-municipality comparison and analysis • standardisation in the capturing of

transactions, account classification, and output of data sets • s tandardisation in key business processes.

National Treasury further defined a standard framework in the Infrastructure Development Management System (IDMS) for business

processes related to infrastructure planning, procurement, project management, operation and maintenance. IDMS maps out gateways requiring specific supporting information that must be defined before proceeding to the next project stage.

This framework aims to ensure that municipalities perform multiyear planning and budgeting across all infrastructure assets and eliminate fruitless and wasteful expenditure. National Treasury also promulgated the Framework for Infrastructure Delivery and Procurement Management (FIDPM), which incorporates the IDMS and “provides the minimum requirement for effective governance of infrastructure delivery and procurement management”.

Obstacles to implementation Challenges with the implementation and continued support of asset management

services are numerous within both local and international environments. An international study with around 1 000 participants was conducted in 2014 to investigate asset management practices, investment, and challenges (reliabilityweb.com). The results indicate that only 19% of organisations’ information management systems supported effective asset management, highlighting the fact that data management issues exist across the world within various sectors.

Therefore, plans or processes to improve data management require constant and dedicated attention.

Asset management maturity scale To perfect the process, organisations need to evolve in terms of an asset management maturity scale (as defined by the Global Forum on Maintenance & Asset Management), encompassing the following categories: • asset knowledge • current asset management practices • information management systems • planning processes • asset management plans • organisation.

The levels of maturity are: • Level 0: Innocent • Level 1: Aware • Level 2: Developing • Level 3: Competent • Level 4: Optimising • Level 5: Excellent.

Climbing the maturity ladder It is imperative that municipalities monitor their maturity levels on a regular basis and make use of specific tools or frameworks that will enable them to get perspective on where they are and where they aspire to be in time.

It is important to note that – although the expectation may be that a municipality’s maturity improves year on year – in practice, the maturity scale is more like a ladder that one can climb both up and down, depending on the dedicated effort taken to manage asset management.

Gap analysis Gap analysis tools are essential for understanding the current asset management status quo within the municipality, together with mapping out the strategic objectives and the expected outcomes.

Gap analysis studies are typically conducted through Delphi sessions using structured questionnaires based on international

Poor asset care and deteriorating infrastructure not only threatens our current way of life, it also limits our growth aspirations.” – National Treasury, 2018 best practice. Delphi sessions are held with key stakeholders responsible for the implementation of asset management within the municipality and outlining the capacity and capability of the existing systems, standard operating procedures and processes, plans and budgets, and data sets (including GIS).

The key output of the gap analysis should be a best value judgement on the condition and performance of asset management within the municipality, using both narrative reports, and visualisations mapping out the current status quo and the municipality’s objective in the short to medium term against global best practice.

Strategic management plan Strategic asset management plans are compiled based on data outputs of the asset management processes, which include the asset register, operation and maintenance data, GIS data sets, including infrastructure, population demographics, and infrastructure condition assessment field inspections. It is critical that the municipality agree and adopt a template framework for the asset management plans such that these can be updated annually and monitored using appropriate tools to ensure that the asset lifespan is maximised.

Dedicated project management An output of the gap analysis (health checks) will be a set of projects or initiatives that are identified to enable the municipality to climb the maturity scale. It is important that each of the project outputs or objectives are specific, measurable, achievable and timely, such that they can be monitored throughout the year.

As an example, the initiatives that may arise from the assessments may include, but are not limited to:

• GIS digitisation processes • automation tools for analysis and reporting • technical support for asset management • report templates • dashboard visualisations • scoping of additional system features required for existing systems • data modelling and database design to include all asset life-cycle stages, including operational data • system integration requirements with other systems • solution architecture and development of bespoke solutions • design and implementation of electronic data capturing tools and processes • development of standard operating procedures and policies • asset-management-related business process mapping across the municipality.

Conclusions Evidence shows that effective asset management implementation requires a dedicated focus. Critical success factors include: - The provision of skilled personnel to manage assets across the life cycle who are held accountable for the operation of the assets and the quality of data recorded in the asset registers. These roles can be supported by external service providers and key experts; however, a unified team is needed and a positive client-consultant relationship is vital.

- Political will to actively manage interdepartmental cooperation to facilitate open channels of communication, which drives budgeting and planning for maintenance, asset renewal and replacement programmes that align with new infrastructure requirements.

- Leadership that drives a municipal culture that motivates all levels of government to be accountable for effective service delivery, promotes accurate reporting, enables proactive escalation of issues hindering service delivery, and mitigates political interference that can derail the strategic asset management implementation process.

Systems are enablers for effective asset management; however, the focus must be on the capacity and skills of the end-users who will operate the systems to achieve the desired asset management goals and objectives.

This is an edited version. The full paper, with references, is available from the authors.

IMIESA September 2022

13

INFORMATION & COMMUNICATIONS TECHNOLOGY

Connecting Africa to the internet

BY LAND AND SEA Along with the rest of the world, South Africa’s evolution within the Fourth Industrial Revolution (4IR) environment depends on accessible, costefficient and fast connectivity in the cloud.

Alastair Currie speaks to Steve Briggs, chief sales and marketing officer at SEACOM, about the shape of things to come.

Steve Briggs, chief sales and marketing officer at SEACOM

14 IMIESA September 2022

S

outh Africa’s first spectrum auction, held on 17 March 2022, raised an estimated R14.4 billion and is a positive development in transitioning all levels of government, business and society (urban and rural) to the 5G environment.

“The Independent Communications Authority of South Africa’s spectrum auction is the start of a longer-term process as mobile cellular operators (particularly the auction winners) invest in new telecommunications infrastructure, such as cell towers,” Briggs explains.

“Our role in support is the progressive installation of our terrestrial fixed-line fibre network across cities and towns in South Africa, interconnected by SEACOM’s subsea cable connection from Europe,” Briggs explains. “Fibre, now and in the future, is the backbone for 4IR connectivity in terms of handling the increasing volumes of large data.”

To ensure the successful roll-out of 5G, South Africa’s current base station density will need to be increased by a factor of four.

Each of the towers will also need a high-speed fibre connection to ensure seamless cellular transmission over what is traditionally referred to as ‘the last mile’ between the signal tower and the mobile device end-user. “We are therefore very excited about increasing demand for fixed-line services,” Briggs continues.

Integrated solutions strategy Positioning for diversified growth, SEACOM is on an acquisition drive to support its information and communications technology (ICT) and enterprise network solutions. Recent developments include the acquisition of EOH Network Solutions and Hymax from EOH Holdings Limited.

These acquisitions, effective 1 September 2022, now enable SEACOM to provide an end-to-end ser vice in South Africa as a converged telecommunications provider, with an allied penetration into the data centre market.

The EOH acquisitions form part of a broader African penetration strategy.

Recent examples include SEACOM’s buyout of privately owned metro fibre networks in Nairobi and Kampala, respectively, along with associated local data centres.

The unfolding subsea frontier “As technology advances, fixed-line data transfer rates will accelerate at everincreasing speeds at ever y stage of the network. This starts at the subsea level,” Briggs explains.

SEACOM’s subsea cable, installed and incrementally upgraded from inception in 2009, is currently rated at 3.2 terabits per second (Tbps). The 17 000 km network interconnects France, Djibouti, Kenya, Tanzania, Mozambique, India and South Africa.

In contrast, Google’s new Equiano subsea cable – featuring

SEACOM is a partner on the Equiano subsea cable project, and we look forward to unlocking the value for customers across Africa as the full system comes online.” space-division multiplexing technology – will run at some 144 Tbps, a revolutionar y step up. This will also be the world’s first subsea cable to incorporate optical switching at the fibre-pair level in contrast to the conventional approach of wavelength-level switching.

“SEACOM is a partner on the Equiano subsea cable project, and we look forward to unlocking the value for customers across Africa as the full system comes online,” says Briggs.

Equiano runs from Lisbon to Cape Town, with branching connections along the West African coastline. The culmination of this journey was the landing of the cable on 8 August 2022 in Melkbosstrand, some 25 km up the West Coast from the City of Cape Town. The first phase is expected to go live in the last quarter of 2022.

“As these blistering data speeds land at the various cable landing stations, the next step is to leverage this capability. This is where the role of the data centre is key, and it’s an asset class that has received massive focus in South Africa in the past 12 months, with multibillion-rand facilities opening up in Cape Town and Johannesburg,” Briggs continues.

at around 10 Gb speeds for the past five years, with some now being upgraded to 100 Gbps. In turn, data speeds on the national long-distance fibre routes are currently at upwards of 400 Gbps.

“In most urban centres, the internet is getting faster and cheaper, and this trend will continue as new subsea cable ser vices land, and the terrestrial fibre network Project Isizwe Wi-Fi installation in Mpophomeni, KwaZulu-Natal

Computing in the cloud

Connectivity trends Currently, in South Africa, the average fibre to the home link is probably around 200 megabits (Mb) per second and 500 Mbps for business links. Gigabit (Gb) speeds are also common in the major metro areas at a cost.

Briggs says the metro fibre networks that process all this traffic have generally been

partners with internet ser vice providers to bring the internet to underser viced and underprivileged communities. The project establishes Wi-Fi zones delivering an uncapped 10 Mbps link for just R5 a day.

“It’s essential that everyone in South Africa is connected, and Project Isizwe demonstrates that it’s definitely achievable,” stresses Briggs.

In an allied development, SEACOM has entered into a collaboration and cooperation agreement with the CSIR to support and develop ICT-based SMMEs. In this respect, the CSIR has developed a new broadband technology, called Television White Space.

SMMEs will be able to use this new technology to connect with targeted markets. In turn, SEACOM will support these SMMEs with on-net ser vices through its enterprise development programme, with further support and training through its partner programme.

increases nationally,” says Briggs. “This will help to shape future Wi-Fi availability and reach the most remote rural areas that don’t currently have good coverage.”

As a responsible corporate citizen, SEACOM supports the Project Isizwe initiative, a non-profit organisation that

Going forward, and for every industry and sector of society, workloads will increasingly be powered in the cloud. Currently, it is estimated that some 60% of workloads globally exist in the cloud. This is predicted to grow closer to 100% in the next five years.

“There’s no doubt that cloud computing combined with super-fast internet takes ever yone into exciting new territor y, working in a secure, intelligent and near-real-time, data-rich environment,” Briggs concludes.

IMIESA September 2022

15

TRENCHLESS TECHNOLOGY

THE ROLKON WAY Durban City Centre Aqueduct

With trenchless construction, a pipe, duct or cable can be installed underground without disturbing service structures such as roads, pavements, driveways, buildings or ecologically sensitive areas. IMIESA speaks to Rocky Herrmann, MD of Rolkon Trenchless Construction, about his company’s unique offering for the underground infrastructure industry.

What sets Rolkon apart from the competition?

RH It is our operating philosophy – leave no site unresolved – that emphasises our solutions-oriented, can-do approach to underground infrastructure, planning and innovation.

Our entire team has adopted this ethos and they have a strong respect for the profession, our work and our clients. I also believe in a team that is invested in their own growth and one that is empowered to be proficient in this profession. I am also proud of Rolkon’s Level 2 BBBEE certification. This is more than a piece of paper; it reflects our efforts to improve and upskill people, as well as provide opportunities for growth.

Occupational health, safety and the environment are key focus areas for us.

All of our work is done with due care and diligence. Our employees are trained, fitted

16 IMIESA September 2022

Rocky Herrmann, MD, Rolkon Trenchless Construction

with the correct PPE and given the right safety equipment.

Furthermore, we value partnerships with our service providers and suppliers (like Bloc Contractors, KZN BCF, Rho-Tec and TrailorSol), as they assist us in providing our clients with safe, reliable, efficient and quality solutions.

What kind of trenchless technologies does Rolkon use?

Rolkon is a horizontal directional drilling (HDD) expert in the 110 mm to 1 000 mm pipe range. HDD is a steerable trenchless method of installing underground pipelines and utilities in a prescribed path bore (straight or cur ved) by using a sur facelaunched drilling rig. It completes jobs with a high degree of precision.

HDD is used to install underground pipelines for gas, sewer, water and stormwater, fibreoptic sleeving and electrical sleeving. We own five machines – a D6, two D9s, a D20 and a

D36 – as well as moling machines, groundpenetrating radars and magnetic scanners, along with support equipment like a truck, trailer, water carts and tooling.

Are there any common misconceptions that you encounter regarding trenchless technologies?

Quite a few municipalities and engineers have successfully adopted this technology, but other municipalities and engineers have little understanding of it. I think it’s important to educate and remind everyone of what is possible with trenchless technologies.

Furthermore, trenchless construction is often viewed as a costly option and the pricing of these projects can be problematic. Cost savings across the entire trenchless construction project must be calculated.

Some of the benefits of trenchless technologies include:

TRENCHLESS INDUSTRY TECHNOLOGY INSIGHT

Due to its non-invasive manner, very little rehabilitation is required after using trenchless construction methods

Sizela sewer line

• Environmental sensitivity: By using specialised equipment, underground infrastructure is installed, repaired or replaced with minimum disturbance to the ecology. This approach means that infrastructure can be fitted under buildings, forests, wetlands and bodies of water. No plants or trees need to be removed, which results in less environmental impact. Due to its noninvasive manner, ver y little rehabilitation is required after using trenchless construction methods.

• Minimal disruption: With open-cut excavation methods, the excavation site must be isolated and may require blocking off entire roads and rerouting the traffic. This significantly disrupts dayto-day activities and leads to traffic jams, people running late for work, or delayed medical and other emergency assistance.

With trenchless technology, little or no excavation takes place. This means fewer street closures and traffic disruption.

• Saves time: With decreased disturbance, projects using trenchless methods take less time to complete. Less time means less inconvenience associated with a construction project.

• Added value: Studies on HDD projects

have shown that trenchless construction can result in 30% more value for money on a given project.

• Less cost: The cost savings resulting from the application of this technology can be significant. Trenchless technologies minimise damage done to surrounding areas. Money is also saved by avoiding the relocation of utilities and the slowing down of traffic (commerce).

• Skills development and labour: In South Africa, trenching is viewed as a job creator when, in truth, more trenches are dug mechanically than by hand; where labour is used, it is predominantly unskilled.

Trenchless technology uses skilled labour and thus growing the trenchless industry will positively increase the resource pool of skilled labour, which, in turn, results in higher wages.

• Safety: there is no risk of the trench collapsing.

What are some of Rolkon’s projects to date?

Established in 2011, Rolkon is based in KwaZulu-Natal and is growing nationally, having several projects in Cape Town, Johannesburg and Mpumalanga. All projects begin with a project plan and a detailed method statement.

Here are some recent projects: • Basement drilling job (Durban Town Centre): Despite building rubble in the confined space in the building, a drill was piloted from the ground floor into the basement, welded a 160 mm diameter pipe and a pulled in a new sleeve.

• Water main (Empuluzi): Rolkon worked for Bloc Contractors where several water main sleeves were installed in various locations. Ground conditions varied from hot and dr y to soft and muddy.

• Fibre sleeve (Cape Town): Working with the Azile Group to pull new fibre ducting for a new fibre network in Gugulethu and Khayelitsha, Rolkon managed to pull between 100 m and 200 m of 110 mm fibre ducting per week.

• Traffic signals (Midway Mall): The Rolkon team spent the better part of the drill pounding through the rock-hard sur face of the ground to find soil conditions conducive to pulling ducts for the traffic signals outside the Midway Mall in Newlands. And although the drill took longer than expected, all the crossings were completed as planned. The length of the drill was 75 m, with two 110 mm ducts pulled to ensure the effective functioning of the new traffic signals.

• Sewer sleeze (Sizela): A 400 mm sewer sleeve for a new sewer line was built by Bloc Contractors. During this 30 m drill, Rolkon had to cross the main road and navigate around and below a playground and a wetland area. Additional complexity was brought about by the soft ground conditions and clay soil.

• Water main (King Shaka International Airport): This was an unplanned but urgent job for the Rolkon team, where an 18 m long, 315 mm diameter uPVC water main had to be installed under the road at the airport. The main had to be pushed and not pulled through the drill hole, which took some extra focus in terms of guiding.

Trenchless technology holds many possibilities for both infrastructure development and maintenance. It can assist municipalities and water utilities in obtaining accurate infrastructure condition assessment reports by using cameras to inspect pipeline networks. We believe that with South Africa’s ageing pipe network, the trenchless construction and repair of sewer and pipe networks will increase our volume of work in the coming months.

IMIESA September 2022

17

TRENCHLESS TECHNOLOGY | INSPECTION & MAINTENANCE

Healthy pipelines ESSENTIAL

for SUSTAINABLE living conditions

For a healthy population, it is essential to have healthy pipelines supplying clean drinking water and disposing of dirty wastewater. This is needed in South Africa’s urban areas, where the demand for these services resulting from rapid densification is inadequate or has not been met.

By Alaster Goyns, PrEng*

T

his is in established areas already serviced, as well as in informal and semiformal areas developing around the urban centres. To exacerbate this, there is an imbalance between supply and disposal.

Hence the wastewater accumulates in these communities, drains into the natural water courses and pollutes them. With unhealthy pipelines, the problems escalate.

Under these conditions, due to spatial constraints, installing new services or replacing existing ones in trenches causes disruption and costs to residents and businesses. These implications are seldom considered. This occurs in both unserviced areas and established areas, as densification frequently means that existing services need upsizing. There is also the need for replacement due to deterioration with age.

The alternative is using trenchless techniques for both installing new pipelines, as well as rehabilitating existing ones. These techniques minimise disruption and can cost significantly less when trenches are deeper than 1.0-1.5 m. A critical factor frequently

18 IMIESA September 2022

inadequately addressed when doing things underground is doing the necessary assessment of the subsurface conditions.

This frequently results in site problems and higher costs due to unexpected conditions.

To avoid this, it is essential that any decisions about the action needed should be supported by a thorough assessment of the performance and condition of the asset to be rehabilitated.

Condition and performance assessment To ensure that pipelines remain healthy, they should be periodically checked and, when necessar y, maintained or rehabilitated so that they remain effective and efficient. This evaluation of their health should not be left, as so often happens, until deterioration is obvious, as shown by sewer manholes surcharging, ground subsidence or sinkhole formation.

Assessment should be planned for when the pipeline has reached a certain age and then periodically repeated so that

preventative measures are taken before having to handle unplanned, unexpected and costly failures. Such check-ups should consist of a holistic evaluation of the hydraulic performance and condition assessment of the pipes and manholes.

This should not be viewed just as a means of determining their current status. What happened in the past should be evaluated so what is learnt at present is applied to future planning and service provision.

To effectively evaluate the performance and condition of a pipeline, the basic functions and the theory of how these were applied during the design of the pipeline being investigated should be understood.

Any differences between performance and condition expected after studying site conditions, drawings if they are available, and details obtained from the inspections can be investigated and the underlying causes established.

The primary function of any water conveying pipeline, whether a gravity or pressure system, is to provide the required hydraulic

TRENCHLESS TECHNOLOGY | INSPECTION & MAINTENANCE FIGURE 1 Camera on pole inspection

The traditional approach of sending a camera on a tractor through a pipeline when empty or at low flows only gives a visual output showing the problems, their location, their extent and an indication of their severity.”

Poorly aligned pipe installed about 80 years ago

capacity. To effectively and efficiently do this, three support functions are needed: • watertightness to prevent losses due to exfiltration and additional flows due to infiltration • structural soundness to handle both internal pressures and external loads • durability, so the pipeline can continue conveying the required quantity of water, without any losses or groundwater inflows, and carry the loads imposed upon it.

Stormwater drains versus sewers The remainder of this article covers gravity pipelines flowing partly full. A distinction needs to be made between stormwater drains and sewers. Stormwater drains, particularly those in the warmer parts of the globe, only flow a few times a year as rainfall is seasonal. Hence, access to them is easy.

On the other hand, sewers flow continuously and access may have to be done at periods of low flow or under certain conditions may require the use of over-pumping.

The conditions in sewers can result in the generation and release of hydrogen sulfide (H2S) gas, which poses a serious corrosion potential in cementitious sewers, resulting in strength loss. H2S is toxic and inhalation even at low concentrations can be fatal so the necessary precautions must be taken during inspections.

A realistic assessment of a pipeline requires on-site inspection, in addition to an understanding of the theory used in their

design and then combining this information.

Hence the output from multisensory inspections (MSI) and the basics of pipeline design need to be combined.

Internal inspections of gravity pipelines The traditional approach of sending a camera on a tractor through a pipeline when empty or at low flows only gives a visual output showing the problems, their location, their extent and an indication of their severity.

Typical problems noted are leaking pipe and manhole joints, invert settlement, longitudinal and circumferential cracks, siltation, wall material loss and distortion of the pipeline circumference. However, the actual severity of problems or their underlying causes are not provided.

Using a combination of camera with laser and sonar profilers mounted on a pontoon floated through the pipeline adds value by providing full circumferential dimensional details along the pipeline length. When the external and internal dimensions of the original pipe are known, this allows for the material loss and remaining wall thickness around the pipe circumference to be calculated. This means that the extent, severity and orientation of cracks, wall material loss, circumferential distortion of the pipeline and siltation depths can be determined. In addition, this information could indicate the probable underlying causes of the problems.

The camera on a pole development, as illustrated in Figure 1, used in combination with a surface level survey along the pipeline route, greatly simplifies the initial gathering of information and gives an understanding of the pipeline conditions without needing to send a camera on a crawler, or pontoon through the sewer. On the basis of this, an initial hydraulic and structural analysis can be done, showing where: • there are blockages to be cleared • ponding has occurred indicating invert settlement • there is cracking and its location and type • jointing is poor or misaligned • there is groundwater infiltration • H2S corrosion has taken place above the water line.

This provides the information needed to decide whether a more detailed inspection of each section of sewer is needed or not. If the condition of a section is still adequate, as there are no problems, the cost and time of doing a detailed internal inspection of it will not be necessary and rehabilitation may not be needed.

External inspection of pipeline route By following the route of the pipeline along the surface various external loading conditions such as transportation corridors, buildings and natural features such as water courses, wetlands and ponds can be obtained. The seasonal variations in the latter are very

IMIESA September 2022

19

ROLKON TRENCHLESS CONSTRUCTION THE NON-INVASIVE ALTERNATIVE TO ANY TRENCHING PROJECT. Using Horizontal Directional Drilling (HDD), Pipe-Jacking and Moling, the Rolkon team of skilled drillers and operators provide practical and efficient solutions for the installation of: Underground pipelines for sewer, water and stormwater Fibre optic sleeving Electrical sleeving We are the no-dig option for developers, consulting engineers, contractors municipalities and parastatals.

Rolkon’s accreditations include TTSA, TTUK and SASTT (South African Society of Trenchless Technology). We are registered with the Construction Industry Development Board (CIDB) and carry B-BBEE Level 2.

www.rolkon.co.za info@rolkon.co.za 031 765 7788 / 083 778 2689

TRENCHLESS TECHNOLOGY | INSPECTION & MAINTENANCE Corrosion mechanism in sewers

H2SO4 FORMATION H2S RELEASE

H2S GENERATION

FIGURE 2 An example of a severely corroded sewer. Several phenomena shown here are that the corrosion at the sides is more severe than at the crown, longitudinal horizontal sills have formed at the low flow line, corroded reinforcement is masked by corrosion products, and there’s no corrosion below the low flow level. This 900 mm ID sewer was fed from a rising main with long retention times. The 70 mm walls were corroded through after 10 years

the required pipe strengths calculated.

The location of any surface settlement should Crown wall be recorded, as this could indicate that the pipeline Outside has settled for one or Wall at another reason. The local to any authority should be asked invert sec on about any problems along this pipeline route due to Invert wall manholes overtopping, settlement or sinkhole Outside diameter formation. With cohesive backfill material, even though the pipe walls may FIGURE 3 Physical dimensions to check corrode through in places, the pipes may not collapse. important because this will indicate the (See Figure 2.) However, when exposed, these annual variation of groundwater levels. This pipes may collapse. is particularly important for larger diameter The digitised output of the MSI scanning sewers that closely follow the alignment of above and below water level provides natural water courses. dimensioned internal profiles along the Part of this investigation should be the whole sewer. This also shows where siltation sur face and invert levels at each manhole levels reduce capacity and corrosion losses along the sewer route, as well as the reduce strength. The details from the MSI condition of the manholes. A long section should be complemented by measurements of the pipeline showing invert levels and at a few locations, as shown in Figure 3. the sur face profile can be drawn, assuming This means identifying sections of sewer no pipeline settlement. From the manhole where severe corrosion is anticipated invert levels and the distances between and those that can be easily exposed them, the theoretical hydraulic per formance from the surface so that the inspection of the pipeline can be determined, windows can be cut to do inspections, take assuming that the gradients between measurements, photographs and material the manholes as shown are correct. samples. These physical measurements The earth and traffic loading along the can verify the digitised data and confirm the pipeline can then be determined and sewer’s condition.

Concluding comment Combining MSI observations with the sewer profile identifies the problem areas. By applying theoretical principles, the underlying causes of these can be established and, if necessary, ways of addressing them investigated and applied before undertaking rehabilitation. The rehabilitated pipeline may actually operate more effectively and efficiently than when it was originally installed and its rehabilitated lifespan can be several times that planned for the original sewer.

From the utility owner’s perspective, the critical issue is the sewer’s remaining life before rehabilitation or replacement is needed and the most suitable method for doing this.

A secondary issue is how effectively and efficiently the sewer will perform during this remaining life to minimise its maintenance.

By investigating the differences between the anticipated and actual performance, the underlying causes to problems found can be identified and the preventative measures needed taken when designing new pipelines to avoid past problems.

The two most serious underlying causes of problems observed are variable gradients along a sewer’s length, causing H2S formation, its release and the corrosion of cementitious pipes; and the settlement of founding material under the pipe, causing the opening of joints, resulting in exfiltration, infiltration and sedimentation.

However, problems with sewer health are not just due to design defects or site conditions, but also their misuse due to ignorance.

These two factors cause serious operational problems. Utility owners should address these issues with users to ensure healthy wastewater systems for future generations. *Pipeline Installation and Engineering Services CC

Professional

IMIESA September 2022

21

PRECAST PIPES, CULVERTS & STORMWATER

Culvert jacking operation in progress

MOULDED BY DESIGN:

THE VERSATILITY OF

precast systems

Justin Kretzmar, group sales Alongside classic roles that include bulk water and sewer engineer: Special Products pipelines, precast concrete systems can be fabricated to meet at Rocla and Technicrete an unlimited range of building, structural and environmentally engineered applications. IMIESA talks to Muhammad Bodhania (MB), civil engineer: Technical & New Product Development at Rocla, and Justin Kretzmar (JK), group sales engineer: Special Products for Rocla and sister entity Technicrete, about segments and solutions.

Does Rocla offer professional design and custom build solutions for the water and sanitation markets?

MB Yes, Rocla offers a wide range of standard products to meet diverse applications in these areas. Where viable, and with sufficient economies of scale, we also provide design services for custom-manufactured solutions where standard products are not suitable, typically due to insufficient loading or flow requirements.

Our in-house engineers and drawing office staff are well equipped to engage with clients to fully understand their unique requirements.

From there, we present workable and costeffective precast solutions.

What are some of the most unusual and/or challenging designs completed to date?

MB In the construction industry, nearly every project comes with its own set of unique

22 IMIESA September 2022

challenges and solutions. Two current projects are a case in point. The first entails the supply of 3 x 3 jacking culverts, which are being jacked under an operational railway line; and the second involves the supply of 900 mm RJ 200D pipe to a mining customer. The specification for this mining project is double the maximum strength rating of a standard pipe.

Within the mining sector, we regularly manufacture special heavy-duty culverts designed to support the weight of large haul trucks. In some cases, the rated gross machine weight on these vehicles can exceed 500 000 kg, so the culverts must be robust.

Rocla leads in the development of culvert systems. What are the key product trends in this area?

MB Culvert systems span a very large range in terms of application – from small rectangular run-off channels along parking/warehouse areas to massive culverts below roads or bulk material stockpiles. Recent trends here include

Muhammad Bodhania, civil engineer: Technical & New Product Development at Rocla

jacking culverts for trenchless projects – e.g. under a busy highway. Here, the culverts are precast into singular square units and then jacked from one side to the other, below the existing traffic loading.

At Rocla, we manufacture jacking pipes with internal diameters ranging from 900 mm to 2 500 mm, with a 100D strength rating. In turn, the span and height of our jacking culverts are 2 m x 2 m, up to 3 m x 3m, with a strength rating of 100S.

What are some of Rocla’s milestone trenchless supply projects to date?

MB We’ve completed various bulk water jacking projects during the past three years.

These include: - 836, 2 250 mm jacking pipes at S4 Pipelines

A Rocla HDPE lined sewer pipeline installed in Polokwane

Technicrete permeable pavers forming part of a SUDS installation

One of Rocla’s largest culvert jacking designs

- 116, 1 800 mm jacking pipes in Meyerton - 90, 3 000 mm x 3 000 mm jacking culverts at Iscor Heights.

What are some of the key challenges and opportunities for upgraded/new stormwater systems in response to climate change?

How can Rocla help combat corrosion and maximise life-cycle utilisation in sewer systems?

JK The biggest challenge is that storms with increased severity are occurring far more frequently than in the past. For example, in some areas, we are experiencing three 1-in-100-year storms within one rainy season! This is a challenge also for design engineers, as traditional legislation and design philosophies do not cater for this unprecedented trend. The result is repeated and extensive flooding.

Existing stormwater systems clearly cannot cope with this scenario. First, due to increased hardstand areas (owing to urbanisation and construction), and second as a result of rising water volumes and their intensity.

Existing networks are difficult to upgrade and new networks are subject to budgetary constraints where ‘over-designing’ to meet current storm patterns might be deemed ‘over-budget’. This may result in a repeat of traditional design approaches and the installation of new systems that cannot cope with current requirements from day one.

Rocla, of course, has a myriad of pipe and culvert products designed for the underground transportation and harvesting/ attenuation of stormwater.

Additionally, traditional stormwater crossing precast rectangular portal culverts with matching base slabs are also employed for walkway tunnels, cable trenches and vertical inlet water channels incorporating a slotted cover. An example of the latter would be the Beany Block and Max Tech Systems, designed as either a continuous horizontal kerb inlet and channel system or vertical inlet system running full length across open hardstand areas.

Our wingwall product range for both circular and rectangular portal culverts is also very popular with contractors, as these offer an instant installation solution for protection against erosion at both ends of pipe or culvert lines.

MB Rocla collaborates with the various stakeholders to ensure a durable solution.

From the product manufacturing side, this may include special concrete mix designs (using different aggregates that are more/ less resistant to attack/degradation), addition of increased cover (sacrificial layer), special admixtures, cast-in linings like HDPE layers, etc.

What are some of the key Rocla developments for bulk water?

MB One that stands out is the modification of concrete pipe sections and large (70 kℓ) rectangular chambers for underground water storage or attenuation requirements. Other examples include the manufacture of jacking culverts, jacking pipes and square manholes used in bulk water systems. In fact, the increased use of precast concrete for water storage reservoirs is gaining traction in the bulk water industry in general.

Is the rainwater harvesting segment gaining traction?

JK Not really, but this needs to be considered on two different scales – small residential (typically less than 10-15 kℓ) and large commercial (typically larger than 100 kℓ).

There’s definitely interest from the residential sector in harvesting water, but our systems are difficult to retrofit, as our individual modules are about 6 tonnes each and hence difficult to offload and manoeuvre around within an existing property/building. On the larger scale, where our systems are costeffectively suited to installation below, for example, an existing parking area, the cost of a complete system is still prohibitive when considering a payback period.

Allied to this, our sister company, Technicrete, supplies worldclass sustainable urban drainage systems (SUDS) via its permeable paving product line.

Technicrete’s SUDS offering is an ideal system for storing or attenuating stormwater within stone layer works below a paved area.

Thanks to the permeable nature of this hardstand area, water flows through the top layer and infiltrates into the ground, recharging groundwater sources and, where applicable, eliminating riverbank erosion.

Another Technicrete product – Armorflex – is specifically designed to transport surface water from point A to point B without eroding this flow path deeper and deeper with each storm. Armorflex is ideally suited to trapezoidal channel construction, as well as for roads in very wet regions where other engineered surfaces degrade rapidly from constantly flowing water.

Overall, it’s important to note that maintenance of all stormwater systems is vital to ensure that their design flows are not compromised. Within the municipal space, this remains a challenge in our country.

What type of quality assurance systems does Rocla offer the market?

MB Our products are CMACS (Concrete Manufacturers Association Certification Services) certified to all the relevant SANS specifications, as well as ISO 9001 conformance. This includes internal QA systems to ensure that products are consistently of high quality and compliant to the relevant codes.

And in closing?

JK Precast concrete offers high-quality, durable and time-saving solutions, and its use is gaining traction within the building and infrastructure segments where in situ concrete has predominated. Examples include reservoirs, building components (slabs, walls, stormwater channels and SUDS), electrification and lighting poles, and tilt-up construction.

Thanks to advances in concrete technology and fabrication processes, the use of precast systems also helps to reduce carbon footprints while bringing down the overall cost of construction.

IMIESA September 2022

23

INNER-CITY RENEWAL

THE ONYX:

engineered for the future

C

Once the centre of Johannesburg’s diamond and mineral trade in past decades, the Jewel City precinct has been transformed into a vibrant mixed-use space that serves as a major catalyst for urban renewal.

A prime example is The Onyx development.

overing six city blocks within Johannesburg’s CBD, the revitalisation of Jewel City began in 2018 following its acquisition by a joint venture development team comprising the Divercity Urban Proper ty Fund, Ithemba Proper ty, and Atterbur y Proper ty Fund.

The transformation since then has been remarkable, as the previously derelict office buildings and warehouses in Jewel City – alongside greenfield projects – are repurposed into a secure inner-city neighbourhood that forms part of the CBD’s Maboneng Precinct.

A mix of mainstream commercial tenants at street level creates convenience for city living – as well as safe and welcoming public spaces – with a wide and pedestrian-friendly central avenue on Fox Street interconnecting Jewel City with the greater CBD. Distinctive cladding elements are part of the warehouseinspired design elements

24 IMIESA September 2022

of concrete, where the project won the ‘Buildings of more than R50 million’ category.

Hergen Fekken, structural engineer and director, EDS Engineering Design Services, expands on the key concrete construction elements.

A greenfield pioneer Spearheading the change at Jewel City is The Onyx, a new 13-storey apartment building that has been celebrated for both its design and construction innovation.

Housing 665 residential apartments over 11 levels, The Onyx’s design includes ground-floor retail and parking, adding up to a total gross leasable area of 21 703 m². An iconic architectural masterpiece, the construction components are equally outstanding in achieving a costeffective and functional structure.

Industry recognition includes the 2022 Fulton Awards, which celebrates excellence and innovation in the use

Foundation design

“The structure is a reinforced concrete frame resting on CFA friction piled foundations to account for poor soil conditions and high water tables, and in some instances double and triple pile groups were required to resist high column loads,” says Fekken.

From foundation level, there are two basement parking/retail levels where generally 400 x 750 50 MPa RC columns resist the vertical loads. “The columns allow for a more open and flexible space on these levels,” he explains.

At ground-floor level, a transfer level was designed to transition the vertical loads to concrete bearing walls for the upper floors.

This transfer level typically comprises 900 wd x 1 100 dp transfer beams with 40 MPa concrete strength.

The concrete bearing walls are a combination of 230 mm and 160 mm thick concrete Form and function come walls, with two layers together to create dynamic of reinforcement. living spaces Concrete of 40 MPa

Yo u r

Off-shutter concrete finishes

PROJECT TEAM Client/Developer/Owner: Divercity Urban Property Fund/ Ithemba Property/Atterbury Property Fund Project Manager/Principal Agent: GASS Architecture Studios Structural Designer: EDS Engineering Design Services Architect: GASS Architecture Studios Specialist Subcontractor: WBHO Construction

Va l u e

www.marleypipesystems.co.za

WHY USE MARLEY

TWIN-WALL? 1.

2.

SABS APPROVED

Twin-wall is classified as heavy duty underground sewer pipe 400kPa

Concrete Supplier: AfriSam SANS 1601 - Type 2

was specified for these walls up to third-floor level, and 30 MPa up to roof level. As Fekken explains, this load-bearing system advantageously allowed for repeatability during construction, and one-way spanning slabs, resulting in a very efficient slab design. The upper slabs are generally 200 mm thick, 25 MPa conventionally reinforced one-way spanning slabs. These typically span 5.4 m between the concrete bearing walls. An added advantage of this approach is that there are no protruding columns into the residential unit spaces.

In turn, the building’s lateral stability was provided by the two lift shafts (central to the building) and two stair shafts (on opposite ends of the building).

P a r t n e r

3.

4.

Twin-wall is available in plain ended or socketed at one end

Twin-wall is easy to cut using Marley’s unique pipe cutter

5.

6.

The solution for heavy duty applications

Complete 400kPa system.

(Pipe & Fittings)

Concrete mix The concrete design involved a mix of crusher sand, filler sand, different sized stone, cement and ground granulated blastfurnace slag (a by-product from iron production). Different concrete strengths were specified for different elements ranging from 25 MPa to 50 MPa depending on the design requirement.

In each case, the water/cement ratio was optimised, generally with a lower water content to achieve higher concrete strengths.

SIMPLE, STRAIGHT CUT EVERY TIME -

Marley’s unique pipe cutter saves time and promises ease of installation.

Cutting pipe has never been easier. No chamfering is necessary.

Built to last Radiating positive energy, The Onyx marks an important milestone for Johannesburg’s CBD transition, with the simplicity of its warehouse-inspired design features drawing inspiration from its surrounding industrial roots. The ultimate result is a modern interpretation on the evolution of sustainable social housing and urban living.

The building overlooks a new urban park with outdoor relaxation areas and multiple retail offerings

The effect of a 400KG mass on deformation under load

PIPELINES

TWIN-WALL PIPE

REINTRODUCED TO

THE SOUTH AFRICAN MARKET Industry leader Marley Pipe Systems SA is excited to announce the return of the Twin-Wall heavy duty 400 kPa uPVC sewer pipe to the local market.

The lightweight 400 kPa sewer uPVC Twin-Wall pipe is a heavy-duty underground pipe available in plain-ended or socketed in 110 mm and 160 mm sizes

M

arley Pipe Systems SA has more than 50 years of experience and a proven track record of manufacturing and distributing high-quality and reliable products across sub-Saharan Africa in a socially, environmentally and The unique pipe cutter allows installers to make a clean cut without having to chamfer economically responsible manner. the pipe for a smooth finish Marley Pipes Systems SA's TwinWall pipe will make another great addition to the company’s extensive Marley Pipe Systems SA’s factory is ISO and reliable range of products.

9001:2015 accredited and adheres to The reintroduction of Twin-Wall pipe stringent process controls of the highest will complement the company’s existing international standards. Its products range of 100, 200 and 300 kPa pipes. carry both the South African Bureau The product will be manufactured and of Standards and the Southern African distributed locally from the Marley Plastic Pipe Manufacturers Association factor y in Nigel, Gauteng.

(Sappma) stamp of approval.

The effect of a 400 kg mass on deformation under load

As illustrated above, Marley Twin-Wall maintains its structural integrity under pressure

26 IMIESA September 2022

Enhanced strength The lightweight 400 kPa uPVC Twin-Wall system is a heavy-duty underground pipe available in plain-ended or socketed in 110 mm and 160 mm sizes. The TwinWall pipe is manufactured with a double wall with the corrugated outer wall providing improved strength.

Ease of installation The heavy-duty pipe is designed for easy installation and by using the patented Marley Pipe Systems SA cutter. Installation time can be reduced by as much as 70%.

Fur thermore, the unique pipe cutter allows installers to make a clean cut without having to chamfer the pipe for a smooth finish.

Installers will also be happy to know that the company’s entire range of 110 mm and selected 160 mm underground fittings is compatible with the corrugated design of the TwinWall pipe due to the new lip seal in the range of underground fittings. The Twin-Wall pipe can be used in heavyduty applications as well as light and medium-duty applications.

The Twin-Wall pipe will be available to installers as of September 2022 and Marley Pipe Systems SA representatives will be available to attend to all enquiries and facilitate any training required.

To find out more about Marley Pipe Systems SA’s Twin-Wall heavy duty 400 kPa uPVC pipe, call +27 (0)11 739 8600 or visit www.marleypipesystems.co.za.

Thank YOU

FOR YOUR SUPPORT

SAPPMA and the Plastic Pipe Conference Association (PPCA) would like to thank all the sponsors, speakers, exhibitors, delegates and everybody who participated in this year’s PIPES XIII Conference for making it such a resounding success.

32 papers presented

200 delegates from South Africa and around the world

15 sponsors Our conference was themed: ‘The Versatility of Plastic Pipe’ and the event certainly lived up to expectations. The level of conference participation and interest signals an industry that is poised to play an even greater economic role throughout the entire plastic pipe supply chain in South Africa and beyond.”

Jan Venter, CEO of SAPPMA

www.sappma.co.za

19 exhibitors

SAPPMA

THE EXCITING EVOLUTION

OF PLASTIC PIPE Showcasing innovation and excellence, local and international speakers and delegates came together for an informative and engaging Pipes XIII conference, under the theme ‘The Versatility of Plastic Pipe’, with some 32 papers presented. The conference was cohosted by the Southern African Plastic Pipe Manufacturers Association (Sappma) and the Plastic Pipes Conference Association (PPCA). By Alastair Currie

O

Dr Roelof Botha

pening the event, held at strongly following Emperor’s Palace between the international 6 and 7 September 2022, economic meltdown Jan Venter, CEO, Sappma, caused by the set the scene referring to the impact of pandemic.

This Covid-19 on the South African and global global recovery is good news for South Africa, Europe, the Ukraine conflict is a pressing economy. Industry challenges include and we’re confident that this trend will ripple concern – contributing to a global energy polymer shortages, as well as a sharp through to our markets where there’s enormous crisis – plus climate change impacts are escalation in related materials pricing. potential, spurred on by pressing infrastructure causing widespread droughts in southern “This event serves as a stimulus for the priorities,” Venter explained.

(Visit Europe. Water shortages are also renewed focus and scope for plastic pipe, www.sappma.co.za to access the increasingly widespread in Southern Africa. particularly within South Africa and the Pipes XIII presentations.)

Our contribution as an industry is to provide broader Southern African region. Pipes XIII Added Zoran Davidovski from PPCA: “We sustainable solutions that support sociohas brought together some of the most certainly live in interesting times. Within economic prosperity.” respected players in our sector, and Outstanding speaker line-up there are excellent takeaways in Benchmarking against local and terms of research and development international experiences, the Pipes trends, leading projects, and best First Prize: Sizabantu Piping Systems South Africa XIII speaker line-up included a practices,” said Venter.

Second Prize: McNeil Plastics selection of top papers presented at “Encouragingly, indicators show that Third Prize: Bausano PPCA’s 2021 PIPES XX conference the European and North American in Amsterdam. The PPCA hosts plastic pipe industries have rebounded

BEST EXHIBITOR AWARDS

28 IMIESA September 2022

SAPPMA

A key ‘Large diameter and thick wall HDPE development is the pipes produced in the Middle East progressive increase in – three case studies’. pipe diameters and pipe First-time installation strength, enabling plastic pipe in Riyadh to successfully compete on As Vigellis explained in his presentation: “Polyolefin pipes performance and price in now have a successful 70-year the space traditionally histor y. Continuous innovation filled by steel and of raw materials, manufacturing equipment and processes mean concrete systems

Keynote speaker Dr Roelof Botha presenting to delegates at Pipes XIII

BEST PAPER AWARDS Presenter: Dolores Herran Company: Molecor, Spain Title of presentation: ‘PVC-O DN800: Efficient transformation from soil to irrigated land’ Presenter: Grigorios Vigellis Company: Union Pipes Industry LLC, Middle East Title of presentation:‘Large diameter and thick wall HDPE pipes produced in the Middle East – three case studies’

its international conferences in Europe or the USA ever y second year, with a spinoff event ever y alternative year in another region. The last PPCA spin-off conference in South Africa was co-hosted with Sappma in 2017. Members of PPCA include the PE 100+ Association, the Plastics Pipe Institute, and the European Plastic Pipe and Fittings Association.

“Across the globe, plastic pipe technology is making a positive difference, as reflected at Pipes XIII. We are making headlines with our pipelines and ideas,” Davidovski added.

Topics and winning papers This year’s themes reflect the tremendous diversity of the plastic pipe sector, and

its myriad applications. “One of the remarkable aspects about plastic pipe is its sustainability, providing lifespans of 100 years or more with minimal maintenance inter ventions. Papers in this area expanded on material durability studies, and the correct installation and welding techniques,” Venter explained.

A key development is the progressive increase in pipe diameters and pipe strength, enabling plastic pipe to successfully compete on per formance and price in the space traditionally filled by steel and concrete systems. The awardwinning Pipes XIII paper on this topic was presented by Grigorios Vigellis from Union Pipes Industr y LLC, Middle East, entitled

that PE pressure pipes up to 3 500 mm diameter and PE or PP nonpressure pipes up to 5 000 mm diameter can be produced and have earned the trust of design consultants.”

Of the three case studies presented, Union Pipes Industry LLC’s wastewater project in Saudi Arabia is a prime example of the new frontiers opening up for large diameter plastic pipe applications. Quoting from the paper abstract: “A large diameter HDPE pipe of 3 000 mm SDR 30 with 100 mm thickness was used to connect the exit of an established underground concrete tunnel (3 m ID – lined with HDPE) with the main Al Haer sewage treatment plant in Riyadh. This 3 m HDPE pipe was laid in a 11 m deep excavated trench in single welded pipeline strings of 500 m long. This was the first time that a 500 m plastic pipe string of 3 m in diameter has been lifted up in one piece and then installed 11 m down by using 27 parallel cranes.”

Innovation in Spanish irrigation Pipes XIII’s other award-winning paper was presented by Dolores Herran from Molecor in Spain and entitled ‘PVC-O DN800: Efficient transformation from soil to irrigated land’.

Quoting from Herran’s abstract: “This case study is about a project to transform 244 hectares into irrigated land in the La Sarda region of the municipality of Pedrola (Zaragoza, Spain) with DN800, PN16 bar pipes, and about how the most costeffective alternative was chosen among cast iron, helical steel and reinforced concrete with metal sleeve.

“Molecular orientation applied to PVC pipes has been around for a few decades now, but we cannot say the same regarding large PVC-O pipes (from DN800 to DN1 200),” Herran writes.

IMIESA September 2022

29

SAPPMA

“The current state of the art technology applied to this sector opens up fields of application not explored before with PVC-O pipes… The supply conditions (with a ver y high instantaneous flow in a ver y short period of time), the high installation per formance in metres/hour, the anticorrosion properties, ease of assembly and lightness, among others, were the main reasons why PVC-O pipes were chosen.”

Keynote address

A large diameter HDPE pipe of 3 000 mm SDR 30 with 100 mm thickness was used to connect the exit of an established underground concrete tunnel (3 m ID – lined with HDPE) with the main Al Haer sewage treatment plant in Riyadh, Saudi Arabia. This was the first time that a 500 m plastic pipe string of 3 m in diameter has been lifted up in one piece and then installed 11 m down by using 27 parallel cranes

30 IMIESA September 2022

For South Africa, renewed investment in infrastructure, industr y expansion, employment and SMME development are especially important for the countr y’s economic reconstruction after Covid-19.

Despite the challenges experienced in the recent past, keynote speaker and renowned economist Dr Roelof Botha said that South Africa’s future is looking up, supported by a series of encouraging economic indicators.

“While there are daunting challenges like youth unemployment, we are definitely seeing a new lease on life for South Africa following a period of over-regulation and maladministration, as revealed in the Zondo Commission report on state capture,” he explained.

As Botha stated, “Poor economic leadership under President Jacob Zuma’s administration resulted in losses in GDP of at least R2.5 trillion, tax revenue foregone of R635 billion and cost each South African around R48 000. Additionally, an average of 1.2 million more jobs could have been supported with better leadership and a more competent state.”

Serious under-per formance and wasteful expenditure within state-owned enterprises (SOEs) has been a key contributing factor to poor socio-economic outcomes, placing a brake on meaningful social infrastructure implementation. A knock-on effect within the power segment has been an ongoing spate of load-shedding, and a spike in oil prices.

“However, the fact remains that South Africa is classified as an upper-middleincome countr y, with an abundance of resources and the most diversified tax base of any emerging market,” he explained.

A paradigm shift “As we speak, there’s a major paradigm shift taking place as South Africa moves away from poor to sound economic policies,

SAPPMA

best per forming currency globally over a three-year period against the US dollar.

“The rand is not weak; the dollar is strong, and this has a positive benefit for South African exports. To illustrate the point, in 2021 South Africa’s total exports came to around R1.7 trillion, a 60% improvement on 2020, with 2022 looking ver y positive,” Botha noted.

South Africa’s agricultural sector continues to break output records annually. “Agriculture value added at cost in 2021 prices reached a new high during Covid-19, and in 2020 it was the second highest ever. Currently, around 35% of current food exports go to sub-Saharan Africa. Outside Africa, the largest food export trading partners are the Netherlands, followed by the United Kingdom,” he continued.

From left, from Sappma: Ian Venter, technical manager; Enrike Albasini, administration officer; and Jan Venter, CEO

with private-public partnerships integral to the process. The excellent news is that the private sector is already expanding its investment in new productive capacity,” said Botha.

“In addition, the Johannesburg Stock Exchange reached an all-time record high earlier in 2022 showing positive investor appetite,” he continued. Botha pointed out that earlier in 2022, the rand was the

Skills and employment A lack of skills capacity and an ongoing brain drain remain a major stumbling block for South Africa. “Our Department of Home Affairs has a critical skills list. The first prize would be to encourage skilled South Africans working overseas to come home,” said Botha.

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that total formal non-agricultural employment increased by around a million between January and June 2022, which supports the overall positive economic uptake.

“South Africa’s transition to a more free-market-based economy positions the country for growth, which will be spurred on by massive infrastructure investments. Going forward, I believe the outlook for a sustainable 4% GDP growth rate in the not too distant future is achievable,” Botha concluded.

Delegates networking at Pipes XIII

Investing in education, and especially STEM (science, technology, engineering and maths) at primar y through to tertiar y level, is crucial in preparing job entrants for increasingly high-tech industries that include manufacturing.

In parallel, addressing more immediate employment needs is a must in South Africa, where the extremes between the rich and poor make South Africa one of the most unequal countries globally. In this respect, the South African government hasn’t ignored the problem.

In terms of ranking in per capita terms, Botha points out that South Africa remains the fourth best emerging market worldwide for temporary employment creation through public-funded programmes. “A case in point is the approximately one million jobs created through South Africa’s Expanded Public Works Programme in 2021,” said Botha.

Stats SA reported South Africa’s unemployment rate at 33.9% for Q2 2022 – down from 34.5% in Q1. While these statistics are still alarming, Botha said

A Molecor PVC-O DN800 PN16 bar pipeline section installed in Spain

Closing remarks However, the fact remains that the local construction industry is 24% smaller than it was before the pandemic (according to Stats SA) and needs a huge capital injection in terms of projects.

“Sappma and its members remain committed to providing quality solutions for industry and the excellence showcased at Pipes XIII underscores this capability. In this respect, I’d like to extend our sincere thanks to the presenters, delegates and exhibitors, with a special thanks to our sponsors, and PPCA, all of whom play a vital role in promoting the greater use of plastic pipe,” said Venter.

“Going forward, we will continue to work with public and private stakeholders to ensure that plastic pipe is central to the solutions we need to rebuild and grow South Africa’s economy,” Venter concluded.

SAVA is encouraging local manufacturers of PVC pipes and fittings to join our efforts to promote a responsible, healthy and sustainable PVC industry.

Buy PVC wisely.

Members belonging to SAPPMA and other industry associations enjoy a special, discounted annual fee.

In return, they become eligible to display the Green Tick - a product label that communicates to end-users that their products adhere to SAVA's strict Product Stewardship Commitment and that they are lead-free, use additives approved for high human contact applications and are recyclable.

Safe, responsible and sustainable.

When buying PVC water pipes and fittings look for the Green Tick!

Choose pipes & fittings with the Green Tick

www.savinyls.co.za CEO@savinyls.co.za (021) 531-0313 or (071) 083-5219

SOIL MECHANICS

BEDDING, EMBEDMENT, BACKFILL AND COMPACTION

E

ngineering soils are produced by the erosion of the earth’s crust.

They change in character by being moved from the source. Particle shapes change from angular to rounded, and are then sorted and graded. Water is the most productive of all soil-forming agencies (see Arthur Casagrande’s Soil Classification).

Classification of engineering soils The classification of engineering soils is a complex and exacting science that requires extensive investigation, testing and analysis to precisely define a given soil (see COLTO classifications G1 to G9).

There are four basic methods of designing a road structure. These methods, based on AASHTO Soil Classification, are not applicable to bedding, embedment and backfill of pipelines: 1. Group Index Method: US Highway Engineers’ empirical quantity calculated from the soil’s grading and Atterberg limits.

2. Shear Strength Method: links it to theoretical stress imposed on pavement and subgrade that ignores repeated loading effects.

3. Californian Bearing Ratio (CBR) Method: subgrade empirical property measured by empirical penetration test.

4. Modulus of Elasticity Method: considers this the critical soil property.

However, for the purposes of bedding, embedment and backfill of a pipeline, the broad general classification of soils may be sufficient as follows: • coarse-grained or non-cohesive soils • fine-grained or cohesive soils • organic soils (peat); extremely treacherous and troublesome.

The characteristics of coarse-grained (sand) material is preferable for bedding, embedment and backfill for a pipeline – although limited amounts of fine-grained (clay) material, indicted by the PI (Plasticity Index), can be tolerated but must be specified and controlled.

Soils are mixtures of particles of various sizes, but the properties of a soil are, to a

34 IMIESA September 2022

great extent, determined by the predominant particle size in its composition – the MIT (Massachusetts Institute of Technology) classification system is based upon particle size.

Results of sieve analyses are plotted as a grading curve; the log-scale abscissae are particle sizes and percentage by weight finer than the given particle size, the ordinates. For engineering purposes, a well-graded material has greater strength and stability.

Two figures provide an approximate description of material as follows: 1. Effective size – maximum particle-size of the smallest 10%.

2. Uniformity coefficient – ratio of the maximum of the smallest 60% to the effective size.

A uniformity coefficient approaching 1, the minimum possible, shows a high degree of uniformity.

Two fine-grained soils with similar grading curves may have widely divergent engineering properties and characteristics caused by the varying properties of the clay minerals in the soil and their different effects when the moisture content varies.

Fine-grained soils, formed by slow settlement of particles suspended in water during which consolidation and drying occurs, go through clearly defined stages, the Atterberg limits.

Moisture content is the ratio of the weight of water to the weight of solid in a given volume.

Thermoplastic pipes Reinforced concrete pipes have dominated the gravity pipeline market because engineers know that when a reinforced concrete pipe

Everything a civil engineer designs and constructs rests on, or in, the earth.

Soil mechanics play a pivotal role in laying pipes.

By Mike Smart*

is delivered, the conduit and structure is delivered too. With a thermoplastic structured wall pipe (SWP), only the conduit is delivered and the structure must be constructed on-site.

Thermoplastic SWP relies on the ‘soil-pipe’ structure that is constructed in situ with the pipe and its embedment.

Compaction is the expulsion of air, consolidation the gradual expulsion of water, from the pores of saturated cohesive soil. Two common compaction tests, Standard Proctor (25 x 5.5 lb x 12”) and Modified AASHTO (25 x 10 lb x 18”), classify the density of a material.

Thermoplastic pipe standards, thermoplastic pipe literature and TEPPFA specify 95% Standard Proctor compaction but the South African construction standard, SANS 2001-DP1 Earthworks, specifies: - 90% Modified AASHTO for bedding - 93% Modified AASHTO in traffic areas for cohesive soils - 98% Modified AASHTO in traffic areas for noncohesive soils.

These road construction specs are potentially detrimental to thermoplastic pipes – because compaction energy goes into soil and pipe alike.

The compactive effort applied to the sample in the Modified Proctor (Mod. AASHTO) test method is over 4.5 times that applied to the same size (1/30 ft³) sample in the Standard Proctor test method. The Modified Proctor, known as ‘heavy’ compaction, was devised by AASHTO (American Association of State Highway Transport Officials) to simulate conditions where heavy compacting equipment is used in highway construction.

TABLE 1 Comparison of Original and Modified Proctor

Method Name Standard Proctor Modified Proctor

Applicable Standard ASTM D698 AASHTO T99 ASTM D1557 AASHTO T180

No. of Lifts 3

No. of Blows 25

Mass lbs 5.5

Drop inches 12

Energy ft-lb/ft³ 12 375

5

25

10

18

56 250

It is imperative that the compaction of the embedment supporting the haunch of the pipe is conforming to enable the compaction of the embedment at the ‘halfpipe level’ to be conforming to enable it to transfer loads on the pipe to the trench walls, to limit the deflection to the predetermined design magnitude.

The ETH’s (Swiss Federal Institute of Technology Zurich) IGT (Institute of Geotechnical Engineering) produced a technical report in December 2004, ‘Correlation between the values of Compaction AASHTO-Standard and AASHTO-Modified’ – the results of which are reproduced in Graph 1.

GRAPH 1 Correlation Standard AASHTO and Modified AASHTO η = 0.95 = SC Well graded sand-clay mixture; excellent binder η = 0.97 = GP Poorly graded gravel/ gravel-sand; little or no fines η = 0.97 = GW Well-graded gravel/gravelsand; little or no fines

SOIL MECHANICS

TABLE 2 Standard Proctor and Mod. AASHTO Tests Comparison

Method Name Standard Proctor Modified AASHTO

Layers No. 3 5

Blows No. 25 25

Mass lbs.

5.5 10

Drop inches 12 18

Compaction ft-lb/ft³ 12 375 56 250

Equivalent energy 56 per layer 25 per layer

Note: Both tests use a cylindrical mould, 4 inches in diameter of 1/30 ft³ volume. Both samples receive equal energy if 56 blows are applied in Standard Proctor

The relationship between the compaction factors is dependent upon the classification of the soil being compacted. A Casagrande Classification SC material will achieve 95% Standard Proctor compaction with 90% Mod. AASHTO compaction. Different classification soils will have different ratios for the two compaction methods.

A comparison of the compactive effort of the test methods is shown in Table 2.

Well-graded soils compact better than poorly graded soils. Moisture content

36 IMIESA September 2022

in excess of optimum moisture content reduces dr y density because the pore water pressure pushes the soil particles apart, increasing the volume between them.

Thermoplastic SWP manufacturers must understand, when the pipe has been manufactured, delivered and joined in the trench, approximately half the work to construct a pipeline has been done. The other half is the construction of the ‘soil-pipe’ structure on-site that must be conforming if the pipeline is to

function as designed. The SANS 2001DP1 must be revised to take cognisance of the requirements of thermoplastic pipelines by replacing Modified AASHTO with appropriate Standard Proctor values.

The thermoplastic SWP requirement, that a ‘soil-pipe’ structure is constructed, must be explicitly expressed in contract documents to establish its importance to the conformance and per formance of the pipeline.

The bedding, embedment and compaction of the pipeline is an integral part of the pipeline’s construction to enable it to deliver its designed ser vice life, of not less than 50 years, as a sustainable buried conduit. *Owner of Genesis Consulting. References available from the author on request: mike@genesislabour.co.za.

INSTRUMENTATION

Customised IoT pressure management solutions Efficient processes are at the hear t of digitalisation. With close to five decades of recording and processing measurement data, Keller offers a range of solutions – from pressure sensors to the finished web app.

T

he path towards digitalisation begins with recording data, mostly with sensors. In addition to other values, pressure sensors can record the levels of lakes, rivers, groundwater, drinking water storage in JoJo tanks (game reserves) and pressure drops in pipes (non-revenue water). This data is mainly transmitted wirelessly via radio transmission, using technologies such as LoRaWAN or mobile communications (NB-IoT, LTE-M), and then saved to the cloud. It can then be retrieved on all possible end devices such as computers, tablets or mobile phones.

IoT service package The internet of things (IoT) describes physical objects with sensors that connect and exchange data with other devices and systems over the

Keller comprehensive IoT service package

internet or other communications networks.

Keller offers a comprehensive IoT measuring system that allows the user to take an immediate step towards digitalisation, without much effort and at a low cost, where: • no software solution or hardware needs to be created • a working and tested measurement data recording system can be accessed • separate, technically advanced training is necessar y.

Keller’s measuring system is designed so that each part of the measuring chain has a specific interface. The user can incorporate the measurement data processing system into their own information system due to an open cloud application programming interface (API). All individual interfaces are available, so that users have free choice, in terms of implementation, as to whether they would like to set up the entire system or only parts of it.

The sensor that records the data is one of the most important parts of the IoT system because decisions are made and actions taken based on its measurements

Step by step approach to digitalisation

1 Specify 2 3

4 5

Individual integration levels from the pressure sensor series 9L up to the KOLIBRI Cloud web app

6

The extent to which vertical integration is implemented depends on the application and involves weighing the costs against the benefits

7

data recording points/ measuring points.

Define a suitable pressure or level sensor based on requirements such as accuracy, compatibility of media.

Select transmission technology by assessing available network coverage at measuring point.

The measuring points selected should be as close as possible to the person responsible for the system so the discrepancy can be found and remedied in the event of a fault on-site.

Verification of the measured values recorded should also be performed during operation at the measuring location.

Operate measuring points with the help of a graphical representation in a cloud for a few weeks and monitor closely.

Expand the measuring system (POC) with additional, possibly technically critical measuring points and close monitoring of any discrepancies.

Up to step 5, the IoT Keller measuring system is used with little investment. It must now be assessed whether the system is to be kept as it is, or whether a deeper integration of the system into the company’s software is desired.

Automatic data synchronisation between the measuring system and the company’s own cloud. Many service providers do not know the process of generating IoT measurement data. Keller can assist in establishing clear and concrete functional requirements for the measurement data it records in an external system.

Complete vertical integration.

IMIESA September 2022

37

ROADS & BRIDGES

ROADS AND ECONOMICS are interlinked

Sound road infrastructure enables economic growth, investment and much required skills within a country. This crucial message will be central to the upcoming 7th Regional Conference for Africa, to be held from 18 to 20 October at Cape Town International Convention Centre.

P

Basil Jonsson, operations director, SARF

rofessor Andre Roux, a keynote speaker at the event and head of the Futures Studies Programme at the University of Stellenbosch Business School, stresses: “Infrastructure counts, and it counts a lot.”

In terms of African countries, where optimal road networks are often “a bit few and far between”, he further adds: “It is one of the most important fundamental requirements of overall economic growth and development.”

The international conference – which is being hosted by the South African Road Federation (SARF) in collaboration with the International Road Federation (IRF) and the World Road Association (PIARC) – is drawing delegates and speakers from across the globe. While many are coming to share in best practice examples from other countries, Professor Roux believes that many are also coming to seek out opportunities on the continent.

“The fact that the continent has such a huge infrastructure deficit implies there are actually a great number of investment opportunities,” he says. “Africa has a growing middle-income class and these are the consumers that really drive an economy; the bigger this economic group in a country, the greater the demand for a whole range of goods and services.”

in terms of sufficient, well-maintained and safe road networks.

“Getting the goods from factory floor to the market becomes a big challenge,” notes Roux. “And it also goes way beyond just the roads network; it also needs to include digital infrastructure, good solid institutions with integrity; and entire educational systems geared towards the right kinds of skills.”

Basil Jonsson, operations director for SARF, agrees, noting that the three-day programme has been tailored to embrace all these factors: “We have talks ranging from the optimisation of road networks in rural areas and publicprivate partnership financing models, to digital transformations in transportation data collection, new road and pavement materials being developed for sustainability, and the importance of upgrading skills and capacity throughout our sector.”

Supply chain networks

Key focus areas

The problem, notes Roux, lies in connecting the goods produced with the consumer base demanding them. Even in South Africa, where excellent goods are produced efficiently in factories, very real supply chain problems exist

The programme on the first day of the conference (Tuesday, 18 October) will focus on road needs and financing, the preser ving of Africa’s road assets, as well as safe and efficient transport by road. This last

38 IMIESA September 2022

Professor Andre Roux, head: Futures Studies Programme, University of Stellenbosch Business School topic will continue on to Day 2 (Wednesday, 19 October), which will also include talks around the role of low-volume roads, as well as innovative practices (both of which will continue on to Day 3) and capacity development. Day 3 will introduce the subject of roads and the environment.

With a strong emphasis throughout the conference on road safety, one of the other highlights around this topic will be a workshop hosted by the UN Institute for Training and Research (UNITAR) on ‘Management Practices for Safe Roads’. A panel of renowned international and local experts will include Professor Benjamin Colucci, a global stalwart in the areas of transportation and construction, as well as Angela Montano, project lead on UNITAR’s Road Safety Global Training Initiative.

ECSA accreditation has been secured by SARF for the conference, with 1 CPD Point in Category 1 for each of the three days. A vibrant trade exhibition (with 37 exhibitors in total) will be central to the event.

For more information, contact SBS Conferences & Exhibitions on +27 (0)71 348 1780, email info@sbs.co.za or visit sbs.co.za/sar f2022.

ROADS & BRIDGES

Promoting the use of WASTE IN ROAD CONSTRUCTION The CSIR’s Case Studies Project Team was a recent finalist at the National Science Technology Forum (NSTF) Awards 2021/2022.

T

he CSIR’s entr y, entitled ‘The use of waste materials in road construction’, was submitted in the Green Economy Award categor y.

Led by project leader and principal researcher Georges Mturi, the CSIR team comprises Johan O’Connell, Imraan Akhalwaya, Nonzwakazi Ncolosi, Vincent Ojijo, Tladi Mofokeng, Michandre Smit, Nomashaka Hawes, Theresa George, Ashiel Rampersad, Refiloe Mokoena, Cameron Munsamy, Kele Makamu and John Letwaba. They have been working with partners from the road pavement industry that include AECI Much Asphalt, Dow, WBHO, BSS, Merchelles Collective, Roadspan and Roadmac Surfacing.

To date, the CSIR Case Studies Project Team has been involved in several research initiatives geared towards providing alternative waste material products for use by the asphalt pavement industry in South Africa. The research focus has been centred around creating a more inclusive and sustainable approach to

Construction of the road trial section at the University of Pretoria’s Engineering 4.0 facility using bitumen modified with plastic waste in the asphalt surfacing

future road construction, particularly through increasing the potential for job creation, creating greater economic benefits, producing better-performing roads, and trying to resolve South Africa’s environmental challenges.

Micro-fillers, plastic waste and recycled tyres So far, the team has worked on three case studies. The first case study involved the CSIR collaborating with AECI Much Asphalt to use locally available micro-fillers and recycled tyres to pave a 200 m long section of road as part of a controlled trial in Roodepoort, Gauteng. This trial section included a 60 mm modified high modulus asphalt base layer that was constructed over a cleaned gravel base layer treated with a bituminous emulsion before paving.

In the second case study, the project team demonstrated the use of plastic waste in asphalt mixes. This was an initiative of the Department of Science and Innovation funded through the Waste RDI Roadmap

Team members involved in the construction of a road trial section at the R80 in Tshwane using plastic waste coated aggregates in the asphalt surfacing

Implementation Unit led by Professor Linda Godfrey. The addition of plastic waste directly to the aggregate is called the ‘dry modification process’ or ‘dry method’ of plastic asphalt modification.

To prove the feasibility of this technology, a road section was constructed on the P159/1 (R80) highway in Tshwane and subjected to heavy vehicle simulator testing using a mobile laboratory that can simulate 20 years of heavy traffic in less than six months.

Wet method trails The third case study (recipient of the Dow Impact Fund) involved the use of plastic waste via the wet method (plastic waste added directly into bitumen) in the asphalt surfacing layer of a 100 m test section at the University of Pretoria’s Engineering 4.0 facility.

WBHO-funded construction started early in June 2022 with the layer works. The asphalt surfacing with plastic waste was paved in mid-July 2022. The section is currently undergoing preparations for heavy vehicle simulator (HVS) testing.

“All these case studies are ongoing research to provide alternative solutions for the road pavement industry,” states Mturi.

Adds Ray Govender, director, WBHO: “They demonstrate the potential of sustainable use of recycled materials that have an economic benefit for the industry, while solving environmental challenges for the country.”

IMIESA September 2022

39

VEHICLES & EQUIPMENT

A new all-rounder in the

HEAVY-DUTY TRUCK CLASS

The cab on the FUSO TV33-400S 6x4 truck tractor meets ECE R29 regulations. This involves front-impact, static roof strength and an optional impact test on the cab’s rear wall

A robust new offering from the FUSO Trucks stable, the latest-generation TV33-400S 6x4 truck tractor is aimed at the short to medium haul, distribution and construction segments.

T

ested within the South African environment, the new FUSO TV33-400S will be assembled at Daimler Truck Southern Africa’s East London manufacturing plant for Southern African distribution. Geared up for local and export markets, the East London facility celebrates 60 years of operation in 2022.

A well-established Daimler Truck brand globally, FUSO offers a comprehensive range of vehicle solutions extending from around 4 to 33 tonnes gross vehicle weight. The FUSO TV33-400S 6x4 falls into the heavy-duty categor y, with a key focus on power, productivity and fuel efficiency, together with an equal emphasis on driver comfort and safety. In addition to the on-road experience, the cab interior places major emphasis on driver ergonomics, both

40 IMIESA September 2022

Maretha Gerber, vice president: Sales and Marketing, Daimler Truck Southern Africa

in terms of the seating configuration as well as the sleeper cab section.

“Southern Africa remains a focus market for FUSO Trucks and the launch of the FUSO TV33-400S 6x4 enables us to field a highly cost-competitive offering across all major segments in the heavy-duty market,” says Maretha Gerber, vice

president: Sales and Marketing at Daimler Truck Southern Africa.

Headquartered in Kawasaki, Japan, FUSO Trucks traces its roots back to 1932 and currently fields five truck and two bus product lines in around 170 markets worldwide. Key components and kits for the TV33-400S 6x4 truck tractor sold locally are sourced from Daimler India Commercial Vehicles (DICV), based in Chennai. DICV’s Research & Development team at the Chennai plant has also been instrumental in the design and production of the latest rendition of the TV33-400S 6x4.

The FUSO brand first entered the South African market in 2002 and sold 136 units that year. Since then, the offering has expanded significantly to meet all industr y requirements in the light, medium and heavy classes. As with any marketing

strategy, new models are launched in response to customer requirements.

“Customer feedback during the testing of the TV33-400S 6x4 was highly favourable, especially in terms of the build quality, driveability, ground clearance, economy, plus overall cost of ownership. This is a truck that will keep on working,” Gerber explains.

Sustained power under all driving conditions The FUSO TV33-400S provides maximum torque from low rpm, which delivers the optimum balance of power and control in all driving conditions via the truck’s automated manual transmission. In addition, the truck is set up with a heavy-duty hub reduction rear axle with a two-stage differential lock, enabling the vehicle to tackle challenging terrain. Power is delivered by a Mercedes-Benz 12-litre OM457 Euro 3 engine, and the fuel tank has an anti-theft feature that prevents siphoning of the diesel.

On the move, the driving experience is enhanced by an improved cruise control system

and speed limiter function, plus Eco and Power mode buttons.

In turn, safe stopping power is achieved thanks to the ABS air brake system and auxiliary exhaust brake.

All inspection and maintenance points are easy to find and access via the front service flap. Another key feature is the new electrical cab-tilt function – with no manual intervention required – enabling safe and easy access to the engine bay.

“We have a range of service and maintenance contract options available as part of our after-sales strategy, which, along with excellent parts availability, forms part of our integrated customer support solutions. Our goal is to ensure that every FUSO TV33-400S sold delivers over the long haul,” Gerber concludes.

Visibility on the FUSO TV33-400S has been enhanced with the fitment of distinctive dual-chamber headlights and LED daytime running lights

SERVICE INTERVALS AND WARRANTY Engine oil change: 50 000 km or 1 000 hours Coolant change: 100 000 km or 12 months Transmission oil change: 150 000 km Differential oil change: 150 000 km Warranty: Four years or 300 000 km

ELB AWARDED GEHL PARTNER dealer status

A

s recognition of its commitment to excellence, ELB Equipment received a major accolade when the company was awarded the status of partner dealer at a recent GEHL conference in France.

“Being awarded with the status of partner dealer is a great honour for ELB Equipment.

Our business model is that of a multibrand franchise and securing our relationship with a brand that shares our ideals and has a heritage older than our own is imperative to upholding that business model,” says Keon Kardolus, sales manager: Earthmoving and Construction at ELB Equipment.

ELB has been distributing GEHL equipment since 2018. The product range includes backhoe loaders, skid steer loaders, telescopic handlers, and articulated wheel loaders.

Kardolus credits the success of the brand to GEHL’s heritage of over 150 years in the construction and agricultural industr y in the USA. This histor y, coupled with a great value-for-money product offering, is also the key to GEHL’s success in South Africa.

“The criteria to become a GEHL partner dealer is not simply achieving a specific sales volume or having a good relationship with your dealer manager, but rather touches on all aspects of the business. ELB Equipment went through a strenuous dealer elevation process that focused on service level, spare parts, technical as well as company image, to name a few,” Kardolus concludes.

IMIESA September 2022

41

WATER & WASTEWATER

BLUE DROP AND NO DROP audits are underway Blue Drop/Green Drop technical lead Dr Marlene van der Mer weBotha speaks to Kirsten Kelly about the audit process for water treatment plants that is currently taking place across the countr y.

O

n 31 March this year, the Department of Water and Sanitation (DWS) released the first Green Drop Report since 2013. With the exception of a few star municipalities and private works, the overall results (as expected) were dismal. Only 23 of the 995 wastewater systems in South Africa achieved a Green Drop certification.

“However, the DWS Minister, Senzo Mchunu, must be praised for releasing these results. They will be used as a baseline and benchmark to plan and incentivise improved wastewater treatment per formance in the future. It is critical that these programmes must be driven from a management, institutional and technical level, with decisive political leadership,” says Van der Mer we-Botha.

In the past, South Africa has given far more attention to water treatment, while wastewater treatment plants were inefficient, received minimal budgets and

42 IMIESA September 2022

Dr Marlene van der Merwe-Botha, Blue Drop/ Green Drop technical lead

inexperienced process controllers. Since the first Green Drop Report in 2009, there has been greater attention on all wastewater treatment plants and the 2022 Green Drop Report will be instrumental in driving their operational improvement.

Blue Drop and No Drop Currently, the Blue Drop audits are under way (from September to December), with the results to be released by the Minister in April next year. “Symposia were held with the water sector around the countr y in June and July 2021, where ever yone was informed of the Blue Drop criteria. It was ver y well attended,” adds Van der Mer we-Botha.

The audit process is conducted by inspectors that are qualified water professionals (engineers and scientists) from both the private sector and DWS. The auditors are only trained on the audit scorecard and IRIS because they already understand the technology, science

and engineering aspects that underline an audit. Audit panels are then formed with a lead auditor; they are then allocated municipalities to assess on a particular date.

Municipalities are notified of the date and time the audits will take place and are required to prepare a portfolio of evidence.

“The first audit takes place in person. Once the desktop audit is completed, one or two supply network points and treatment plants are visited by the audit panel to confirm that the technical and functional status of the actual infrastructure is in line with the desktop audit.

“From there, it is a moderation process.

The municipality will receive back their preliminar y data to make any possible further improvements and gather any other available evidence. After that, there is a virtual confirmation audit where the municipality can present further evidence and the scorecard is updated accordingly.

Then there is another moderation process

WATER & WASTEWATER

to produce the final Blue Drop results, after which data is processed and the various provincial and national reports are developed. These reports undergo various quality assurance phases after which the Minister signs off the report,” explains Van der Mer we-Botha.

History and changes to the Blue Drop programme The Blue Drop and Green Drop certification programmes were launched in 2008. In 2014, the No Drop programme was also introduced to focus on water losses and non-revenue water from municipal water distribution systems. The release of these reports was halted in 2013, though all were reinstated last year.

Van der Mer we-Botha states that the Blue Drop audit process this year is ver y similar to the process prior to 2013, and is centred around monitoring and complying with SANS 241. However, there is greater attention to the financial side of treatment plants.

“We benchmark budgets and expenditure and

calculate what it costs to treat a kilolitre of water at a specific quality.” Given the many incidents of water quality failures around the countr y, risk-based monitoring is now a sizeable portion of the scorecard.

All programmes are established around incentive-based regulation that has later been coupled with risk-based regulation.

“We do not use the term ‘penalise’ loosely. These programmes are geared towards incentivising good practice, responsible behaviour and compliance with legislation and standards while disincentivising under-per formance and dysfunctional infrastructure. The audit process is consultative and we encourage municipalities to ask and learn from the auditors on how to improve their Blue Drop score and, thereby, water ser vices in ensuring good-quality drinking water,” adds Van der Mer we-Botha.

The Blue Drop and Green Drop fall under the Regulation, Compliance, Monitoring and Enforcement Division of the DWS and any non-complying, failing, dysfunctional system will be issued with directives.

Municipal managers and technical managers will be held accountable for their systems. The underlying governance and accountability drivers are valuable elements of the Drop programmes.

She adds that many municipalities have deeply committed water officials working for them. “We have the foot soldiers but without support from management and leaders, the correct tools, knowledge

and competencies, that commitment is fruitless. The right people must be appointed in the right position, and existing staff must be trained and upskilled. We see a direct link between good Drop scores and competent staff and investment in officials responsible for wastewater/ water treatment.”

The programmes now also place a greater focus on the qualifications and experience of people within the water departments of municipalities.

Energy Water and wastewater infrastructure is one of the major consumers of energy within municipal operations and ser vice deliver y.

Energy use typically represents around 30% of the costs of running a water and wastewater treatment plant and electricity prices are predicted to grow above inflation levels ever y year.

“For the water sector, electricity becomes a critical driver from a budget and technology point of view, and for quality water and effluent. Therefore, energy has been introduced into the Green Drop and Blue Drop audit criteria. Municipalities now have a fresh perspective on energy efficiency and capacitated municipalities provide good data on the cost of their electricity per kilowatt hour, the amount of electricity used, as well as energy management plans to become more energy efficient and to generate energy,” states Van der Mer we-Botha.

The water sector has been shown to hold the greatest electricity savings potential within municipal operations and is thus a high priority for energy-efficiency investment by municipalities. Establishing a baseline costing for energy, given that it is usually the single highest cost in delivering the ser vice, is good management practice and will provide a strong basis from which to calculate and motivate the financial opportunities that efficiency measures may provide.

“This is the strength of these programmes; they can be used to push and motivate for a resolution to a particular

IMIESA September 2022

43

WATER & WASTEWATER

problem. It also provides a per formance comparison between treatment plants,” adds Van der Mer we-Botha.

Tackling the Blue Drop programme Van der Merwe-Botha encourages all municipalities to tackle their water safety plan, as it is a good starting point to achieving Blue Drop status. “Water safety plans rely on sound integrated water quality management principles that are quite simple to implement but, as with most management systems, they require attention to detail, planning and discipline in execution. By identifying risks, a plant can prioritise certain projects and allocate budgets and human resources in a meaningful manner. The water safety plan can be used to motivate for human capital and sufficient budgets. It creates an enabling environment for the improvement

of water treatment plants and ensures safe drinking water to users.

“I am encouraging municipalities to get their teams together, include their finance and procurement departments, and start compiling the portfolio of evidence to identify (and address) any gaps. Everyone (technical, procurement, financial) must be available for the inspector on the audit date; a venue/ room should be organised for the audit and it may be a good idea to do a dry (practice) audit before the actual audit takes place.

Remember that the physical sites must be ready, as a few will be visited by the auditor,” she says.

A few quick wins include registering process controllers on the IRIS system, creating water safety plans, and doing condition assessments of the water network, pump stations and treatment works, while adhering to risk-based management and SANS 421.

NO DROP, BLUE DROP AND GREEN DROP • No Drop – falls under the Water Use Efficiency Division of DWS, measuring water usage indicators such as water use per capita, water losses and water use efficiency.

• Green Drop – provides an analysis of the current state of wastewater infrastructure and management in the country, and also tracks performance and compliance over time.

• Blue Drop – measures and assesses all aspects contributing to the provision of safe drinking water.

44 IMIESA September 2022

“I would like to remind municipalities that the public, state officials and funders will see their Blue Drop results and they therefore need to maximise their efforts and preparation for the Blue Drop audit,” states Van der Mer we-Botha.

All three programmes have been punted as a truly unique South African solution to South African problems that set an extremely high standard in water and wastewater treatment. “Green Drop, Blue Drop and No Drop status is only achieved if a 90% score is reached. I am extremely proud of these programmes as well as the people on the ground that are working on these programmes. The Green Drop Report has already added a new energy into the sector and is inspiring water professionals.

I believe the Blue Drop and hopefully future No Drop reports will continue with this momentum,” she concludes.

WATER & WASTEWATER

THE OZONE

AND UV REVOLUTION

The world is yet again undergoing a revolution in water treatment, this time led by ultraviolet (UV) light and ozone technologies. By Chetan Mistry, strategy and marketing manager, Xylem Africa

T

he chemical treatment of water is ver y effective but it also has drawbacks. Other than the environmental concerns, it’s not always practical to use chemicals such as chlorine on a smaller scale or for specific applications. Treatment facilities are also keen to reduce the amount of chemicals they have to stockpile and manage. Ozone and UV have become popular, as either alternatives or complementar y additions to chlorine systems.

UV and ozone are very potent non-chemical ways to destroy many types of water contaminants, including bacteria, parasites and viruses (even SARS-CoV-2), as well as the removal of some metals. Both UV and ozone are naturally occurring cleansing agents. UV’s power was discovered 140 years ago when scientists worked out that sunlight kills some types of pathogens.

The UV light triggers chemical reactions inside microorganisms that essentially destroy their genetic structures and make it much harder for them to reproduce.

Ozone is far more aggressive, attacking the cell walls and coatings of viruses, cysts, pathogens and bacteria, killing all

on contact. Ozone also reacts with colour, taste and odour compounds, leaving a clear, tasteless sparkling water behind.

UV and ozone often complement chlorine treatment systems to create safe drinking water from heavily polluted water sources, allowing for the safe reuse of wastewaters back to potable standards.

Many wastewater facilities want to reduce their chlorine use for safety or environmental reasons. They retrofit selfcontained UV and ozone systems to their lines, which drastically reduces chemical usage and manual oversight hours.

Both technologies also stand on their own. They are commonly used to clean fruits and vegetables of bacteria and fungi – the South African citrus industr y is a world leader in using ozone to clean its produce.

Hospitals routinely sterilise rooms with ozone – it’s faster and doesn’t leave a chemical residue. Recently, scientists from Japan’s Fujita Health University proved that low-level ozone gas could neutralise coronavirus particles without causing harm to humans.

Ozone systems are also becoming popular for treating swimming pool water and washing vehicles without using corrosive chemicals. Temporar y or remote locations,

such as construction sites and mines, use ozone and UV to recycle water.

A better world with UV and ozone?

Chlorine remains the most popular choice for treating water. It’s cheap, abundant and ruthlessly effective. Ozone and UV don’t necessarily compete with chlorine. Instead, they help reduce chlorine use, lessening risks and environmental impact, and offer alternatives where chlorine is impractical or dangerous.

Ozone and UV systems today are compact and self-contained. The best products require little to no maintenance. They are either highly portable or simple to add to existing infrastructure. All a company typically needs is access to reliable electricity; then they can run an ozone generator and UV contacting systems.

The technologies do have drawbacks, ozone does not last long, breaking back down to oxygen after just a short period. UV is safe but has limited intensity and all contaminants need to be exposed to the UV light for a short period for it to be effective. Nonetheless, UV is still very effective when used for lower demand cleansing or with other hygiene methods. Ozone is a heavyweight – one of the best disinfectant agents known to humanity.

IMIESA September 2022

45

CONCRETE RETAINING BLOCK SYSTEMS

NEW 4X4 STEP BLOCK CAPS

add a clean finish

The interlocking nature of concrete retaining blocks provides limitless scope for amphitheatre and landscaped seating, along with access stairways. A prime example is a project completed for Durbanville Preparatory School in the Western Cape constructed using Terraforce’s 4x4 Step Block™ system.

The new 4×4 Step Block cap

E

arly in 2022, Durbanville Preparator y School elected to upgrade its sports facilities by reorganising one large field on a slope into a sports facility with two new AstroTur f and two grassed fields. These are terraced on different slope levels.

The client had seen similar school projects using the Terraforce 4x4 Step Block and had used other Terraforce block options for retaining and access stairs previously. This led to the decision to go the 4x4 Step Block route – a block that was originally designed by Terraforce as a supplementar y accessor y for their range of products.

“When used for retaining, the 4x4 Step Block has a unique design that allows you to simply stack up the units with or without mortar, and the corner interlock gently handles convex and concave cur ves to create single or multiple stair ways, seating arenas and ramps,” explains Holger Rust, head and founder of Terraforce. Four 4x4

Step Blocks in a row will result in a flight 800 mm wide.

“The wall angle can var y from vertical to shallow slopes, and steps can be created by turning the block on its side. These blocks can also be rotated for four different elevation choices, and the design allows you to make plants part of your wall,” he continues. He adds that depending on local conditions and the finish required, it may be advantageous to grout the joints with sand/cement slurr y.

Terraforce retaining wall blocks adhere to local and international standards, having undergone extensive laboratory testing according to SANS 207, BS 8006 and ASTM-D6916-18.

Durbanville installation Decorton Retaining Systems, with many years of experience in installing 4x4 Step Block stairs and seating applications, was appointed for the Durbanville Preparator y School project. Together with Klamputs Concrete, a licensed Terraforce block manufacturer based in the Western Cape, they produced a Terraforce precast cap for the L12 retaining wall block units employed as part of the integrated

The 4×4 Step Block caps installed at the ends of the terraced seating sections

46 IMIESA September 2022

QUALITY CONTROL

structures, as well as a custom cap for the 4x4 Step Blocks following a special request from the client. Both cap designs were firsttime applications.

“We are thus proud to present the L12 cap and the 4x4 Step Block cap, which are now available as an add-on to finish top row block segments and the ends of stairs rows and seating, where necessar y,” says Rust.

Curved seating at Durbanville Preparatory School

An example of a 4x4 Step Block design for a seating arena

Project participants: Durbanville Preparatory School Engineer: Lyners Consulting Engineers Main contractor: DP2 Construction Subcontractor: Decorton Retaining Systems

Design and installation challenges During the installation phases at Durbanville Preparatory School, the 4x4 Step Block seating configuration required precise cutting of specified units to match the angles of the curved seating sections, as well as the fitment of the 4x4 Step Block end caps. Overall, 10 000 4x4 Step Blocks, 3 200 L12 blocks and approximately 150 caps were used on-site.

L12 caps for a neater look

"Key challenges encountered included the extremely long seating levels, as these needed to drop considerably,” Rust adds, noting that the 4x4 Step Blocks were filled with a dry concrete mix for additional reinforcement.

As a finishing touch, the seating is slightly sloped to allow water run-off over the different levels of the sports fields, promoting efficient drainage and adding to the overall efficiency of the installation.

­

CEMENT & CONCRETE

Prompt attention to spalled joints HELPS PREVENT COSTLY REPAIRS Spalling of joints in concrete floors should be regarded as an early warning of more serious potential long-term damage. However, the size and cost of repairs can be reduced if the damage is detected and repaired at an early stage, says Bryan Perrie, CEO of Cement & Concrete SA (CCSA).

S

palling occurs due to cracking, breaking or chipping in the immediate vicinity of joints, usually within 100 mm of the joint. “A spall usually does not extend vertically through the slab, but extends to intersect the joint at an angle,” Perrie explains.

Common contributing factors include: - excessive stress at the joint, caused by the accumulation of incompressible material in the joint and subsequent expansion of adjoining slabs in concrete pavements - weak concrete at the joint - poorly designed or constructed loadtransfer devices or failure of such devices - poorly constructed joints.

“Early repair of spalling is needed to improve serviceability, deter further deterioration, and provide proper edges so that the joints can be resealed effectively,” Perrie advises.

“Before any repairs are carried out, it should be determined if the spalling is due to a loss of load transfer at the joints.”

Sounding technique If there is adequate load transfer at the joints, all areas of delamination should be

48 IMIESA September 2022

Bryan Perrie, CEO of Cement & Concrete SA

determined using a ‘sounding technique’ by striking the existing concrete sur face with a steel rod or by tapping lightly with a hammer. A sharp metallic ring will indicate undamaged concrete, while a dull or hollow sound will indicate delaminated areas.

“The area around the perimeter of the patch area should be sawn down with a concrete saw to a minimum depth of 35 mm to provide a vertical face at the patch edges and provide sufficient depth to give integrity to the patch. Additional cuts in the joint to a depth of 25 mm below the bottom of the patch – and extending at least 75 mm laterally beyond each end of the prepared patch boundaries – should then be sawn,” Perrie explains.

The concrete inside the patch area should be exposed to at least 35 mm deep with a hammer and sharp cold chisel or light pneumatic tool until sound and clean concrete is exposed and the patch area is uniform in thickness.

“It is important that tools of the appropriate size are used. Using a pneumatic hammer – which is too large – will cause damage and fracture the concrete below. Under no circumstances

should heavy jack hammering be used,” Perrie cautions.

Joint filler and epoxy resin When all partially loose concrete has been removed, a bond-breaking compressible joint filler (such as expanded polystyrene foam) should be inserted into the existing joint against the existing slab to fill the saw cut. Then a wet-to-dr y epoxy resin should be applied as bonding agent to the entire area, including patch sides. Perrie adds that in larger patches, consideration should also be given to the use of mechanical anchors.

Opening to traffic Following on from this, the hole should then be patched with a concrete designed by an approved concrete testing laborator y to suit the aggregates available and the desired time of opening to traffic.

“The required minimum compressive strengths are 30 MPa for vehicles with pneumatic tyres, and 40 MPa for vehicles with solid tyres. The recommended minimum strengths should be achieved with a cement content not exceeding 500 kg/m3. A water reducer may be

CEMENT & CONCRETE

used. Preferred stone size is 9.5 mm or about a quarter of patch thickness,” Perrie continues.

Where circumstances do not permit a designed concrete mix, trial mix proportions may be used. The correct proportions will permit opening to traffic with pneumatic tyres after three days, and to traffic with solid tyres after four days, provided that the joints can be sawn and sealed within this time.

Perrie says the recommended finishing procedure is to screed from the centre of the patch out to the patch boundaries to promote good bond with vertical concrete faces. Curing should follow immediately by covering the patch with polyethylene sheeting sealed at the edges and maintained in place until the removal of the polystyrene filler.

“When it comes to successfully repairing spalled joints, important aspects include: the need for clean and dr y joint inter faces prior to sealing; priming of joint sides for liquid sealants; providing the proper joint shape factor for liquid sealants; using a bond-breaking cord of closed-cell expanded polyethylene foam; and a bond breaker for liquid sealants. The undersealing of joints – usually 3 mm to 5 mm – is also important,” Perrie concludes.

For further details, consult the CCSA leaflet, Repairing spalled joints in concrete floors, phone +27 (0)11 315 0300 or visit www.cemcon-sa.org.za.

Before any repairs are carried out, it should be determined if the spalling is due to a loss of load transfer at the joints.”

Making construction

attractive to the youth

Avi Bhoora, executive: Construction Materials, AfriSam

H

aving spent a very busy 40-year career in the construction business, Avi Bhoora, executive: Construction Materials, AfriSam, is concerned by the negative attitude of many young people towards this

field of work.

“I do worry about the number of young South Africans who seem to have taken a conscious decision not to enter an industry like ours,” says Bhoora. “There appears to be a strong preference for an ‘office job’ rather than the often-difficult conditions of working on a construction site, for instance.”

Such attitudes make it difficult for companies like AfriSam to compete for the best talent among school-leavers or college graduates, he says.

It is therefore vital for the industry to change this view among potential Youth can look forward new entrants, and to highlight to meaningful and rewarding careers in the the potential for meaningful and construction industry rewarding careers.

A future-proof industry “I have spent my whole life in construction and, as I approach retirement, I am inclined to reflect on how the sector is going to renew itself – so that it can continue delivering into the future,” he says.

An important starting point is for the public to appreciate more clearly that every city, road, bridge, dam, school, hospital or other engineered structure comes from the work of skilled contractors and their supply chain.

“Materials like aggregate must be extracted from the earth to make the concrete for this infrastructure; it is difficult work, but essential for progress,” says Bhoora.

“If the youth can be inspired by these messages, perhaps we can start changing the value they place on the occupations this field offers,” Bhoora concludes.

IMIESA September 2022

49

IMESA MESA

IMESA AFFILIATE MEMBERS PROFESSIONAL AFFILIATES

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

KARIBA SLUICE GATES

rehabilitation ongoing

S

Kariba Dam rehabilitation works in progress

ituated in the Kariba Gorge of the Zambezi River basin between Zambia and Zimbabwe, the Kariba Dam provides hydroelectric power to both countries and has been in operation since 1960.

The double-curvature concrete arch dam has six sluice gates that release water into Lake Kariba. Over time, the concrete has expanded slightly, affecting their smooth operation. Potentially, this could cause these gates to jam in either the open or closed position.

As a countermeasure, the spillway gates are being refurbished one by one in a long-term project that commenced in 2019 and is scheduled for completion in 2025. The programme is being carried out by a consortium, comprising GE Hydro France and Freyssinet International, which was awarded the contract by the Zambezi River Authority.

Temporary cofferdams Before works can begin, the contractors must first create a dry workspace at each gate so it can be refurbished. This entails building a small temporary cofferdam that clings to the dam wall on its lakeside.

Experienced divers affix steel supporting members to the upstream face of the dam wall to allow the cofferdam to be put in place. Here, Pratley Putty was chosen as the best quick-setting solution.

“Pratley Putty is ideal for use underwater but can also fill, seal, build up and bond almost any rigid material,” notes Eldon Kruger, marketing director, Pratley.

A crane on the dam wall lowers the cofferdam pieces into place one by one. The water trapped between the cofferdam and the dam wall is then pumped out into the lake, creating the water-free space necessary for the refurbishment work.

In the final phase of the overall programme, a new self-motorised gantry crane will be installed that can place an emergency gate in position to close any of the sluice gates.

IMIESA September 2022

51

ELECTRIFICATION

Upgrading electricity services in

KWADUKUZA LOCAL MUNICIPALITY Initiated through the Vuthela iLembe LED Support Programme, KwaDukuza Local Municipality is installing a supervisory control and data acquisition (Scada) system and control room to monitor and manage its extensive electricity supply network.

T

he initial groundwork began in 2016 under the scope of the Vuthela programme following a recommendation by the International Finance Corporation (IFC).

The latter identified the need to implement a Scada solution to serve KwaDukuza’s approximately 46 000 customer base and its 120 MW capacity at maximum power demand.

KwaDukuza is a licensed electricity service provider for most of the urban areas within its area of jurisdiction.

In 2019, Zutari (previously Aurecon) was appointed to work on the functional design of the Scada and control room, scoping the integration of 15 existing 33 kV substations and six future 132 kV and 33 kV substations within the KwaDukuza and Mandeni municipalities. It further included specifications for setting up KwaDukuza’s central control room to operate and monitor

the Scada, as well as recommendations for the human resources required.

EU funding Towards the end of 2019, KwaDukuza, with the assistance of the Vuthela team, prepared a business plan proposal for submission to National Treasury, which requested funding from the EU under the fifth call for funding proposals. The submission was successful, and the process started in 2020.

At present, KwaDukuza is in the procurement stage of the project, and Vuthela and the IFC will continue to support the municipality through the implementation phases.

Improved efficiencies Recent studies into the loss of revenue from electricity within KwaDukuza found that several areas of data collection about customers and their usage could be improved. The new Scada system will provide up-to-the-minute information about usage in every section of the electricity supply network, allowing for faults and other anomalies to be identified instantly and suitably addressed. The Scada system is further complemented by an outage

management system to manage and resolve incidents at low-voltage level.

KwaDukuza’s Scada project will drastically streamline the fault restoration process, improve the management of Eskom’s loadshedding programme, and simplify the operation of the medium-voltage network (11 kV) in the municipality.

Local best practice examples A state-of-art Scada system is one of the most cost-efficient solutions. It helps utilities increase reliability through automation, lowers costs and enables problem areas to be detected and addressed automatically and remotely.

As an example of local best practice, Centlec (the utility providing services in Mangaung Metro) implemented a Scada system in 2019, fully integrated to call centre services, allowing the utility to improve its performance in terms of network operations and customer care services. Another local example is the case of City Power, a City of Johannesburg entity, which since 2021 has integrated 51 substations into its new Scada system and plans to integrate another 29 power facilities during FY 2022/23.

INDEX TO ADVERTISERS Cement and Concrete SA Hall Longmore Holdings IMESA - Institute of Municipal Engineering M & D Construction Group Macsteel Fluid Control Marley Pipe Systems Rolkon Trenchless Technology

52 IMIESA September 2022

OBC 10 2, 4 & 50 OFC IFC 25 20

SAPPMA

27

Sika

31

Southern African Vinyls Association

33

Technicrete

35

Terraforce

47

Xylem Water Solutions South Africa

32

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