Precast • Issue 3 • 2021

CONCRETE MANUFACTURING & CONSTRUCTION ISSUE 3 2021

R49,00

PRECAST

IN THIS ISSUE: Raising capital to survive lockdown Cement industry blues Water in concrete mixes

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A LOT OF INNOVATION. EVEN MORE DEDICATION. QUALITY CEMENT. WHAT GOES INTO IT MATTERS.

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Creating Concrete Possibilities

| CONTENTS |

Editor’s NOTE

Fighting back against fi nancial ruin Eighteen months after the country was pushed into Covid-19 despair, compa n ies i n t he const r uct ion industry are still battling to fi nd their feet and a semblance of normalcy.

W hile not ever y company is battling out there, most are unsettled and wishing for a return to usual buying patterns and large-scale projects that can bring about a better sense of stability.

As time goes by and more water f lows under the broken bridge, it is becoming painfully obvious that there will be no magic bullet to end the economic hardship and that every step we take towards a return to normal will be difficult.

We do, however, have the power to start the ball rolling. This can be done by changing our mindsets and removing fear from daily business decisions. Cash in the bank does not translate to future growth and hesitancy means that somebody else might take your opportunity.

This means we will have to trade our way out of the doldrums by extending ourselves and spending money to launch projects, buy equipment and market our products to those who are still trading. Money spent on these initiatives is exactly the incentive the market needs and a shot in the arm for our ailing industry.

Enjoy!

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PRECAST | ISSUE THREE | 2021

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| CONTENTS |

CONCRETE MANUFACTURING & CONSTRUCTION ISSUE 3 2021

PRECAST R49,00

COVER STORY 4

Twinstar Precast quality is the custom

INDUSTRY NEWS 6

SA cement producers monitor sustainability of the industry

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Securing construction material supplies

8

Blockyards can boost housing and employment

IN THIS ISSUE: Raising capital to survive lockdown Cement industry blues

10 Unexpected saviour for cement sales

COMPANY NEWS 11 New yard machine from equipment supplier 11 New Gauteng sales manager 12 Turn unwanted assets into Covid-19 relief funding

PRODUCTS 13 Innovative kerb and drainage system 14 Manufacturing equipment for precasters 16 Spun concrete poles for power transmission and distribution 16 New ceiling tiles

TECHNICAL 17 Strong focus on sustainability in CCSA's new Fulton's Concrete Technolog y 18 UCT conducts experiment on geotextile clogging in PICP 21 Waterproofing adds durability to concrete decks 22 Water quality for concrete manufacturing

PROJECTS 24 Precast arches set the tone for new winery 28 Massive logistics warehouse built with precast concrete 31 Hollow-core slabs used for chemical storage facility 32 Concrete pavers enhance Cape-based lifestyle centre 33 Woodwind housing development chooses Technicrete 34 Retention pond upgraded with Terraforce blocks 36 Multi-faceted cast-stone paving integrates with Franschhoek estate 38 Pedestrian bridge foundations completed

Water in concrete mixes

ON THE COVER Twinstar Precast in Olifantsfontein boldly goes where others fear to tread by manufacturing all types of customdesigned and cast products for civil engineering contractors. While these once-off jobs are usually avoided by typical precasters due to their complexity, size and resource-intensive requirements, Twinstar Precast is specially geared to undertake this type of work and has been doing so for more than six years.

PRECAST is the mouthpiece for the Concrete Manufacturers’ Association – CMA Concrete Manufacturers’ Association Physical Address: Office 0400, Standard Plaza Building, 440 Hilda St, Hatfield, Pretoria Tel: (+27) 11 805 6742 • Fax: (+27) 86 524 9216 E-mail: admin@cma.org.za • Website: www.cma.org.za Publishers: Isikhova Media Address: 10th Floor, Metalbox, 25 Owl Street, Milpark, South Africa Tel: +27 (11) 883 4627 • Fax: +27 (11) 783 2677 www.isikhova.co.za Editor: Raymond Campling Tel: 076 297 2775 | E-mail: media@mediasavvy.biz Coastal editorial: David Beer Tel: 082 880 6726 | E-mail: david.bigsky@gmail.com Managing director: Imraan Mahomed Tel: +27 (11) 883 4627 | E-mail: imraan@isikhova.co.za Pubishing director: Jason Aarons Tel: +27 (11) 883 4627 | E-mail: jason@isikhova.co.za Director of brand strategy: Jenny Justus Tel: +27 (11) 883 4627 | E-mail: jenny@isikhova.co.za Operations director: Thuli Majola Tel: +27 (11) 883 4627 | E-mail: thuli@isikhova.co.za

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The views and statements expressed in this publication are not necessarily those of the editor or the publishers and neither the publishers nor the CMA accept responsibility for them. No person connected with the publication of this journal will be liable for any loss or damage sustained as a result of action following any statements or opinions expressed herein. The same applies to all advertising. Precast © 2021. All rights reserved. No part of this magazine may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage retrieval system, without prior written permission from the publishers.

Creative director: Joanne Brook E-mail: joanne@isikhova.co.za Media sales: Tel: +27 (11) 883 4627 / 083 450 6052 / 072 383 3203

PRECAST | ISSUE THREE | 2021

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| COVER STORY |

Tw instar Precast in Ol ifantsfontein boldly goes where others fear to tread by manufacturing all types of customdesig ned and cast products for civ il engineering contractors.

While these once-off jobs are usually avoided by ty pical precasters due to t heir complex it y, si ze a nd resource intensive requirements, Twinstar Precast is specially geared to undertake this type of work and has been doing so for more than seven years.

Not sur pr isingly, owner-operator, Annemerie Coetzee, is also known to be one of the most innovative individuals in the industry, having ( jointly) received the 2012 CMA Award for Excellence in innovation for her contribution in the design and development of a bomb-proof ATM enclosure.

Growing relationships Her ability to solve problems on behalf of clients has also made Twinstar Precast a favourite of the mainstream precast manufacturing companies who regularly send referrals and make use of her services to manufacture speciality products on behalf of their clients.

According to Coetzee, the company’s success is due to strong relationships within the industry which range from civil engineering contractors, which are direct customers, to architects and specifying engineers who conceptualise requirements, as well as precasters and the broader construction industry.

“With 26 years of experience in the precast industry, I realised that there is a gap in the precast concrete market for custom-made products and once-off items.

In the concrete pipe and manhole market, for example, the emphasis is on high volumes, and the effort and time required to design and build once-off moulds for non– standard products disrupts any normal

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TWINSTAR PRECAST

QUALITY IS THE CUSTOM

well-oiled production line, and in addition requires additional skills and supervision.

Concrete solutions and memorable challenges “Not all building contractors have the necessar y ex per t ise, manpower and facilities to manufacture such products on site and as a result it has become our express aim to assist specifying civil engineers and civil engineering contractors with complicated sites and situations where currently available precast concrete Products just won’t work.

“We strive to be a problem solver and solution driven in all aspects of precast concrete able to manufacture products ranging in weight from 2kg up to 6 tons quickly and affordably. As a result of the complexity of this type of work, we

remain the only company in South Africa specialising exclusively in custom-made and once-off precast concrete products.

“We only keep a few fast-moving products in stock which are standard spec in tenders and drawings. Companies who previously made them have either stopped or have closed down. This has largely given rise to the unique relationship with the mainstream precast concrete companies who make use of certain non-standard products,” says Coetzee.

Twinstar do manufacture square concrete manholes and manhole slabs, as well as polymer manhole covers, stormwater channels and grids, kerb inlet slabs, V drains and chute channels. A recent development has seen Twinstar manufacturing polymer products with no steel or cast iron elements, reducing risk of theft and replacement costs.

“We offer both medium- and heavy-duty solutions with our polymer products, in line with the SANS 1882:2003 specification, and these components can be bought as loose items or cast into the required precast concrete slabs.

“The unusual dynamics in the market over the last two years has seen Twinstar filling the gaps left behind by the numerous

| COVER STORY |

“It is a very complex product, and certainly one of our most challenging,” explains Coetzee. “We got a 3D drawing from an architect, and basically worked by trial and error.” The complexities of creating a mould that would allow for correct tapering of a design into which bicycles wheels must fit without breaking the concrete product was a challenge fit for Twinstar, and the skills and production management expertise it has perfected.”

company closures in the concrete precast market. We now supply Randwater with their custom manhole covers,” explains Coetzee, “and have become as comfortable manufacturing standard products as we are with non-standard products.” One of Coetzee’s more recent favourite projects was stepping in to manufacture bicycle stands for the Ekurhuleni municipality’s recreational park in Springs.

Real solutions and heartfelt values While the company’s manufacturing facility is situated in the heart of Gauteng, deliveries are made across the country wherever custom precast concrete products are required. The company also offers a service where the crane mounted trucks can assist with placing of slabs during installation.

Twinstar Precast is equipped and able to provide installation services on site, in the most challenging of environments.

“My all-time most memorable project was the work we did on closing the Grootvlei mineshafts. The contractor was employed by the Department of Mineral Resources to ensure the safety of the communities around the defunct shafts,” explains Coetzee.

While the shafts had been closed by other means on numerous occasions, they simply could not withstand vandalism and this led to the continuation of illegal mining activities. “Some of the shafts were very deep, and posed great safety risks to the township. Mothers were especially welcoming and supportive of the work we did there, as was the whole community.

The slabs we manufactured to seal the shafts needed lots of reinforcement and had to be designed to be impenetrable. It was totally satisfying to deliver something so life-enhancing to this community.”

Since the installation of mineshaft slabs manufactured by Twinstar Precast, the shafts remain closed and are still completely intact. The design and manufacture of polymer products is another success that dissuades criminals from stealing covers for their steel content.

Keeping the right company The values that make Twinstar such an exceptional business become evident when Coetzee reflects on her loyalty to her staff,

and the human impact of the projects she holds most dear.

She points out that the sk ills and commitment of her staff are central to the exceptional standards Twinstar is known for. “Sixty-five percent of our guys have been with us for five years or longer. They are true artisans with an understanding of the subtleties that go into our production processes. They know precisely how to work with our cement supplier, and how to use the additives to adjust the mix for the outcomes we expect.”

Coetzee has purposefully kept Twinstar to a size that enables the precision changes required for the short lead times committed to, without compromise. “We work in very specific ways, and there is no such thing as a missed deadline. We deliver according to contract, no compromise.” Coetzee also points that there is a certain aesthetic commitment to Twinstar’s products that results from her hands-on approach to everything manufactured. “One of the reasons Twinstar will not create other branches or franchises is that I insist on signing things off; I will not let something leave our doors without being perfect and aesthetically pleasing.” Twinstar has expanded, however, having tripled the size of its factory since 2015.

The environment we build around us increasingly depends on precast concrete elements. Whether stand-alone products, or hybrid construction elements, precast concrete has undeniable advantages. The sky is the limit when it comes to realising new ideas; all it takes is a feasible idea, a sketchbook and a conversation with Twinstar Precast.

First published in Concrete Trends, authored by Nicholas McDiarmid

PRECAST | ISSUE THREE | 2021

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| INDUSTRY NEWS |

SA CEMENT PRODUCERS MONITOR SUSTAINABILITY OF THE INDUSTRY The cement industry in South Africa continues to engage government in creating conditions that will sustain the sector’s local production capacity and grow market demand.

Speaking online at the Cemtech International Cement Conference, AfriSam marketing and sales executive Richard Tomes noted that the rise in cement imports and the application of the carbon tax were among the key issues under discussion. He said the local industry was making steady progress in its climate mitigation journey and that SA was among the leading countries in driving down the carbon footprint in the cement and concrete sector.

Tomes highlighted the fact that cement imports were on the increase again, having peaked in 2014 at about 1,2 million tonnes.

Importers were generally from countries which did not have a carbon tax like that

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which was recently applied by the South African government to local producers.

Neither did importers contribute in terms of social and labour plan initiatives, as they did not conduct any mining activities locally, or operate projects related to the upliftment of local communities.

Unfair advantage “When you have a situation where importers of cement aren’t subject to these added costs, it poses a threat to the viability of the local industry and will ultimately have a negative impact on the levels of employment and social transformation,” said Tomes.

These imbalances, he added, were exacerbating the stresses arising from the country’s longest-ever business cycle contraction, which had seen infrastructure spending decline and had driven a number of large construction companies into business rescue. The Covid-19 pandemic had then accelerated this downward trajectory, leading to dire conditions in the large civils and building industries.

“It’s become increasingly difficult to maintain profitability in an environment of surplus cement capacity and declining infrastructure spending by government,” he

said. “The sector’s total installed capacity is currently about 20 million tonnes, with demand at only around 13 million tonnes.”

Responsible citizens Despite the poor performance of the economy, Tomes noted that the South African cement sector was steadily improving its climate mitigation performance in terms of carbon footprint.

The local industr y was a global leader in developing blended cement technology, making use of waste products such as ground granulated blast furnace slag and pulverised fly ash to extend and enhance its cements.

“This has allowed companies like AfriSam, for example, to achieve average emission levels in its cement production of 574g/kg – which is well below the global average of 890g/kg,” said Tomes.

(Top): Cement is one of the few industries where there is full beneficiation of a locally mined raw material (Left): Cement producers have made significant progress in reducing their carbon emissions.

(Above): Richard Tomes, AfriSam sales and marketing executive.

SECURING CONSTRUCTION MATERIAL SUPPLIES Building materials such as sand, aggregates, fly ash and other components of concrete are key to the success of any construction project and should be a prime consideration for all involved in the industry, including professional bodies.

This is according to Nico Pienaar of surface mining industry association ASPASA, which was one of the founding members of the Construction Alliance SA (CASA), an organisation that seeks to unite all aspects of the construction industry in a common goal of sustainability of the industry.

Since its establishment in response to the Covid-19 pandemic and subsequent lockdowns which threatened to destroy the construction sector, the alliance has sought to establish firm lines of communication between role-players, including raw material suppliers.

Most recently, the SA Coal Ash Association (SACAA) has joined the alliance, representing an abundant source of coal ash which is increasingly used as a principal construction material in the formulation of cement, concrete, ground preparation, as a replacement for some grades of aggregates and even as a replacement for cement.

The inclusion of ASPASA and SACAA in the construction industry supply chain is seen as a critical step towards meeting the country’s construction targets. With its overarching reach across all relevant industry bodies in the industry, CASA will provide raw material suppliers under the banner of these associations with a means of communicating with role-players and working towards common goals.

CASA’s main objectives are to: • Formulate effective joint action plans to achieve its mandate and purpose.

• Address the accelerated transformation of the construction industry.

• Engage in education, training and awareness programmes.

• Unblock relief measures for the industry to remain sustainable.

• Identify infrastructure project opportunities in both the public and private sectors.

• Address the regulatory matters which impede the industry.

• Address systemic challenges and fast-track interventions.

• Promote ethical and social responsibility.

• Promote the use of innovative construction technologies.

• Promote research and evidence-based policy-making for the construction industry.

• Value collaboration, integrity and leadership as guiding forces.

“These principles are also at the head of our agenda and ASPASA and SACAA will play an active role in the alliance to ensure that raw materials are available for any construction project required anywhere in the country. Collaboration is at the centre of all industry bodies in the construction sector and the establishment of CASA will now knit them together in a cohesive manner, with shared goals,” says Pienaar.

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

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Including other related products within infrastructure development and related industries.

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| INDUSTRY NEWS |

BLOCKYARDS CAN BOOST HOUSING AND EMPLOYMENT

With South Africa experiencing a critical shortage in housing and Covid-19 having boosted unemployment, the manufacture of concrete bricks and blocks could help provide affordable building materials and assist in starting small businesses, says Matthews Magwaza, lecturer at Cement & Concrete SA’s School of Concrete Technology.

Among the school’s online courses this year is SCT13 “Making Concrete Bricks and Blocks”, a half-day course providing a rudimentary understanding of how to manufacture masonry units that could become the cornerstone of a new business.

Magwaza says the small-scale production of concrete bricks and blocks for masonry is ideal for entrepreneurs. “Manufacturing can be done outdoors, the process is simple and the equipment required isn’t exorbitantly expensive. However, before starting any brick and block manufacturing (Left): Matthews Magwaza, lecturer at the CCSA School of Concrete Technolog y, says the small-scale production of concrete bricks and blocks for masonry is ideal as a small business venture.

operation, it’s essential to investigate the economic feasibility of the venture.”

Equally important is determining what the demand is for concrete blocks and bricks in the proposed area of operations and whether there is competition from other blockyards. Only once these factors have been established should costs of production and output enter the equation.

To assess costs, the following should be taken into consideration: • The purchase price or rental of the site.

• The cost of site improvements, such as fencing, paved areas for production and stockpiles, pathways, roadways and buildings.

• The cost of equipment such as a concrete mixer, a block-making machine, tools, wheelbarrows and trolleys.

• Water and electricity tariffs.

• The material costs. “As a rough guide, assume that 1m³ of loose aggregate will yield 0,7m³ of concrete volume,” suggests Magwaza.

• The projected output in terms of number of blocks required and their dimensions,

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as well as whether the blocks will be solid or hollow.

• Wastage volumes.

• Maintenance costs of the equipment and site.

• Labour costs.

• The cost of obtaining start-up fi nance.

Magwaza says that in selecting a site, the blockyard operator should consider the distance to the suppliers of raw materials, the market for the blocks and bricks, where the labour force who will be hired live, the quality of security in the area and the availability of services such as roads, water, sewerage and electricity.

Even more training options Concrete manufacturers and contractors throughout SA have unprecedented opportunities to expand their concrete knowledge because of the development of accredited online training courses.

The School of Concrete Technology’s offering of online training this year covers 10 courses, aimed at diverse levels of competency in the industry. John Roxburgh, senior lecturer at Cement & Concrete SA’s School of Concrete Technology (SCT), says that whereas in the past, potential students in places such as Durban and Cape Town were offered only a handful of live courses every year, the introduction of online training by the school now means hundreds of students based in even the most remote areas of SA can register and receive such essential training.

“The time involved in attending the courses has also been drastically reduced.

The courses normally presented live stretched over one to five days, but, in the online environment, the training can be stretched over a few more days to cater for students who need to do most of their studies after work. The SCT is also offering substantial discounted costs this year,” says Roxburgh.

The courses for which “flexi-time” on l ine t ra in ing is now nat iona l ly available are: • SCT10 “Introduction to Concrete”: A course recommended for small-, medium- and micro-enterprises, junior technical and sales staff or any

“The ground should be relatively level, as steep slopes make handling and production difficult. The site should also be big enough to stockpile aggregates as well as cement, production equipment,

block-stacking, staff facilities, a small office and on-site access. Concrete slabs should be provided for the storage of cement (ideally in a weatherproof room, covered with tarpaulins and raised from a possibly damp floor), as well as aggregate stockpiles which tend to be unusable after being in prolonged contact with the soil. Aggregate stockpiles should be on a slight slope so that rainwater doesn’t collect in them.”

(Left): New online technologies mean that students from even the most remote parts of SA need not miss class if they cannot travel. They can now enrol for the CCSA School of Concrete Technolog y’s online training.

•

•

•

•

•

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individual seeking a short introduction to concrete.

SCT12 “Mortars, Plasters, Screeds and Masonry”: Originally developed to assist National Home Builders Registration Council inspectors, the course explains best practices for sand-cement mixes, what can go wrong with them and how to prevent such problems. It is ideal for masons, those managing projects and people who will be assessing the finished work.

SCT13 “Making Concrete Bricks and Clocks”: A course that provides a rudimentar y understanding of how to manufacture masonry units that could become the cornerstone of a new business.

SCT15 “Concrete for Batchers and Batch Plant Staff ”: This course covers important training on how to produce quality readymix concrete.

S C T 2 0 “ C o n c r e t e P r a c t i c e ”: Recommended for foremen, clerks-ofwork, technicians, supervisors, sales and technical staff in the construction and mining industries.

SCT21 “Concrete Industrial Floors on the Ground”: Aimed at helping engineers and contractors by giving a broad, detailed and pract ica l overview of all facets of industrial floor construction.

SCT30 “Concrete Technology”: An intensive course for civil and structural engineers, experienced technicians and technologists, providing detailed knowledge of how cement and concrete

work. Recommended for electrical, mechanical and mining engineers to meet their mining qualification requirements.

• SCT36 “Properties of Concrete for the Structural Designer and Constructor”: A special course for engineers with experience or training in concrete technology to refresh their knowledge of important concrete concepts.

• S C T41 a nd S C T42 “ C onc r et e Technology and Construction (Stages 2 and 3)”, offered by the Institute of Concrete Technology of London: These are ideal bridging courses for potent ial cand idates for the intensive SCT50 “Advanced Concrete Technology” diploma, the world’s leading qualif ication in concrete technology, run at the SCT every two years.

Roxburgh says the online versions of t he training courses have been enthusiastically welcomed by students.

“The lockdown has given people more time to study and they’ve learnt how to use online meeting platforms such as Zoom and Teams. The discounted tariffs now offered by the school have also been a major incentive.

“The fact that we can offer training for a specific company’s personnel – at a suitable time for the client – also means that staff productivity can be maximised, as there’s no travel or lecture room time involved. Furthermore, as the lecture sessions are recorded, a delegate who misses one can view it later,” he explains.

PRECAST | ISSUE THREE | 2021

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| INDUSTRY NEWS |

UNEXPECTED SAVIOUR FOR CEMENT SALES With comparatively low cement sales volumes as a result of the construction industry downturn, the cement industry has looked to the sale of bagged cement in rural areas to bolster supply.

Speaking at mining industry association ASPASA’s annual CEO’s seminar in one of his last public appearances, the late Pieter Fourie of Sephaku Cement said that strong sales of bagged cement in far-flung areas had played a major role in cushioning the effect of the slump caused by the Covid-19 pandemic and other lingering economic factors.

While the construction industry and consumer markets have taken a hammering in recent years, home improvement and small builder activity has shown growth, with more people staying or returning home, where they are undertaking smaller projects.

Shrinking market The local market is estimated to require 13 million tons of cement per annum, while cement producers are producing 19 million tons of cement. Simultaneously, legal and illegal imports of cements continue, adding further pressure to an already over-supplied market.

With two new producers entering the industry since 2014, the market is understandably distressed and the strongerthan-expected demand from rural areas is considered a boon for producers able to reach these customers.

Fourie summed up the four most important challenges the market faces at present: • Uncertainty: There is a lot of political instability and the economic outlook

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PRECAST | ISSUE THREE | 2021

after the Covid-19 lockdown may not be conducive to growth. Carbon taxes and power grid failures also create uncertainty.

• Sustainability: Most companies in the construction industry are suffering from distressed balanced sheets, reduced margins and a situation where prices for bulk cement are at 2014 levels.

• Over-supply: With the entr y of Sephaku Cement and Mamba Cement, the estimated capacity of the industry is 19 million tons and imports account for

1 million tons, while demand has tapered off to 13 million tons.

• Opportunity: Despite the challenges, companies need to put strategies in place to deal with rising opportunities. Largesca le in frast r uct ure development projects are on the cards, consumer spending is increasing and the public and private sectors are re-aligning their priorities in a post-Covid-19 world.

Planning a comeback Until now, the cement industry has undertaken major cost-cutting exercises and mothballed less economical kilns. Investment has been at a low 16% of market value for some time and will require a major jump-start to get back to pre-World Cup boom figures.

Commenting after the presentation, A SPA SA director Nico Pienaar said that these events showed how critical the infrastructure programmes mooted by government were to the construction industry and, by default, to the cement and building material industries.

“With the current low levels of investment in the industry, different approaches are needed and saviours may come out of different directions than anticipated – such as rural bagged cement sales, DIY and home improvements as an example,” said Pienaar.

“The local market is estimated to require 13 million tons of cement per annum, while cement producers are producing 19 million tons of cement.”

| COMPANY NEWS |

NEW YARD MACHINE FROM EQUIPMENT SUPPLIER Kemach Equipment will supply the local market with a full range of BULL backhoe loaders that have earned a reputation for their low fuel consumption and efficient productivity.

All the machines will be supplied complete with air-conditioning, full ROPS and FOPS and an industry-f irst three-year/ 4 000-hour wet drive train warranty as standard. “Through our national network, we’ll continue to offer exceptional support on these products, thus ensuring our customers’ needs are met with optimal uptime and operating effectiveness,” says Kemach CEO Les Lothian.

The BULL backhoe loader offers more productivity and eff iciency, with higher bucket capacity and breakout force, while also being the tallest dumping BHL globally.

Its improved weight distribution makes it highly fuel-efficient, thanks to its power drive and intelligent hydraulic dual pump systems.

The heavy-duty componentry also makes this machine extraordinarily reliable, while still supporting operator comfort and visibility.

“The world has changed and our customer needs have evolved. We believe that with the addition of the BULL product to Kemach Equipment’s expanding world-class offerings, we have the ultimate earth-moving solution across all industries,” says Lothian.

For the past 18 years, Kemach Equipment has built up significant trust with customers in the South African market across various industries by providing exceptional support on its world-class products. It continues striving to delight its customers with bestin-class offerings.

Block Making Machinery

up to 300,000 bricks per 9-hours

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NEW GAUTENG SALES MANAGER Brendon van Vuuren, formerly a sales consultant at Rocla, has been appointed as Gauteng sales manager for Rocla and Technicrete, both of which are part of the Infrastructure Specialist Group (ISG).

Having been part of the Rocla team for over seven years, Van Vuuren says: “I’m delighted to have been promoted to this position for both companies. It brings many challenges with it, especially in the current economic situation that impacts the construction and infrastructure sectors, but I believe that Rocla and Technicrete offer the best precast con-

crete infrastructural and construction solutions in the market. Our design and technical assistance are of a high quality and our delivery reliability is well documented.

“Customer service is one of my passions and ensuring that projects are running smoothly and as scheduled gives me great satisfaction. I believe one’s achievements are the sum total of the efforts of one’s team,” he adds.

Email: sales@panmixers.co.za Tel: +27 (0) 11 578 8700

| COMPANY NEWS |

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TURN UNWANTED ASSETS INTO COVID-19 RELIEF FUNDING Concrete manufacturing companies with their backs to the wall due to Covid-19 lockdown restrictions can turn to auctions to raise much-needed capital without changing the fundamentals of the business.

Auctioning of unwanted assets provides a quick and safe way to inject capital into an ailing business, especially where business fi nance is difficult to obtain or cash is needed in a hurry. Raising money in this manner has the added advantage of minimising debt, as repayment of bank loans can be problematic in cash-strapped situations.

According to Ciena Bester of the SA Institute of Auctioneers (SAIA), there are a number of compelling reasons that businesses should consider a spring-clean to clear out unused or unwanted assets. There are fewer risks involved in selling goods at an auction, the seller exchanges goods for cash and the items are sold as they are, where they stand.

Easy steps “The process is simple and requires an asset list to be compiled and verified by the auctioneer to ensure that all items are present and saleable and that they understand the seller’s expectations. The next step is to sign a mandate which clearly stipulates the terms of engagement and allows the auctioneer to sell the items and to clarify the terms of conditions and requirements for the buyers.

“The auctioneer then puts together a catalogue or auction list and commences advertising in appropriate media during the run-up to the auction. All items will be sold on the auction day to the highest bidder, as per the seller’s confi rmation.

The buyer then has a certain number of days to pay and remove their goods, transfer ownership and complete their transactions. After this, the auctioneer completes and closes the said auction, and pays the sellers.

“Auctions enable you to buy goods in

bulk at a reasonable price. Some buyers can pick up great bargains if they time their purchase correctly. However, potential buyers must ensure that they know what they’re buying, as there are no refunds and no guarantees. Auctions are the only true reflection of the real value of an asset, as the buyers won’t pay more than the item is worth,” says Bester.

Faster option “It’s also important to note that speed of sale is one of the main benefits of an auction, while other factors such as convenience and the safety of the seller also make it a more attractive option than selling out-of-hand. Companies can also move equipment or stock in bulk batches, or even sell all their stock or assets in one auction.”

She adds that there is almost no limit to what can be auctioned: if someone wants it, they will go out and buy it.

Most auctioneers sell moveable assets, including furniture, tools, loose goods, vehicles and plant hire equipment, as well as immovable property in the commercial and residential markets, while others specialise in the fi ne arts, wine and almost anything else.

However, the most critical element of the sale is choosing a professional auctioneer who belongs to a professional body like SAIA, which ensures that its members adhere to a strict code of conduct that obliges them to conduct their business in a fair and transparent manner.

Professionals only “Dealing with SAIA members also offers peace of mind in knowing that the company's dealing with trained, professional auctioneers who have the required expertise and infrastructure needed to fetch the best prices and ensure successful sales and prompt payment,” says Bester.

(Above): Ciena Bester of the SA Institute of Auctioneers.

| PRODUCTS |

INNOVATIVE KERB AND DRAINAGE SYSTEM

With the increase in unseasonably stormy weather, the need for efficient and suitable drainage has increased, particularly for projects that have road or road upgrading elements and related components.

Rocla has recently upscaled the already extremely versatile combined kerb and drainage system – Beany Block and Max Tech – specifically designed for both roadway drainage, with kerbs on either side, parking areas and general open spaces where drainage is required in strips crossing these areas.

The Beany system consists of a series of base blocks of standard channel section and top blocks of inverted channel section with an opening in one side face, collecting water horizontally into the channel section.

The Max Tech system consists of the same base block channel section, but with max tech dog bone slabs placed on top, creating a surface and openings level with the pavement area and hence collecting water vertically into the channel. When laid end to end, they form kerb and/or surface water drainage units strong enough to withstand normal traffic-loading.

A standard top and base block is 500mm in length, with each block having an approximate mass of 70kg, while Max

Tech slabs are 250mm in length (along the channel) and weigh approximately 32kg each. The top block oval openings give an attractive appearance and a continuous line of these blocks provides greater inlet capacities than conventional kerb inlets, with less risk of blockage or damage.

Advantages a-plenty The Max Tech oval slot allows for approximately 18% open area for catchment.

Standard blocks may be used for curve radii of 30m or more. Smaller ones are managed by grouting up wedges created between adjacent blocks.

Problems such as insufficient fall and conflicting levels of service mains and cables are eliminated with the Beany Block and Max Tech systems. The precast elements, shallow excavations and easily-formed drainage profiles offer substantial time-savings over conventionally designed options.

The Beany Block is a substitute for kerbs, stormwater pipework (250-300mm diameter pipes), kerb inlets and parts of footways, while Max Tech eliminates complex cross-falls and provides a continuous collection and carriage system. Contractual claims due to damaged service are far less

likely to occur compared with conventional drainage due to the shallow excavations involved in the installation of the system.

Suitable applications There are numerous applications for the Beany Block and Max Tech combined drainage and kerb system: • Applications where high inlet capacity is required.

• Wide carriageways.

• As a division between vehicle and pedestrian/bicycle lanes with drainage from both sides.

• Parking areas.

• Taxi ranks and bus depots.

• Wash bays and vehicle service areas.

• Median islands and industrial areas.

• Drainage around buildings and walkways.

• Toll plazas.

• Intersections of roads and driveways.

The Beany Block drainage system has undergone strength tests and the top and base blocks have been designed to withstand accidental 80KN axle-loading. The (unreinforced) Max Tech has been designed for 30KN axle point loads.

(Top): The Beany Block-Max Tech combo.

“The Beany Block is a substitute for kerbs, stormwater pipework (250-300mm diameter pipes), kerb inlets and parts of footways.”

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| PRODUCTS |

MANUFACTURING EQUIPMENT FOR PRECASTERS Suppliers to the building industry, as well as contractors and developers in rural areas, have access to a wide variety of precast concrete manufacturing equipment through the country’s leading equipment supplier, Revaro Concrete Equipment.

The company supplies a wide range of concrete manufacturing machines to manufacture almost every element of a house from bricks to block, pavers and retaining blocks, roof tiles, lintels, hollow-core slabs and even concrete pipes and poles.

It also caters for other construction types, such as structural (eg bridges, foundations, parking garages, retaining walls, etc), as well as different types of buildings like office blocks, hospitals, shopping centres and schools.

The company stocks a full range of machines for almost all precast concrete requirements and diverse precast materials, as well as a wide range of sizes to make it affordable for companies from start-ups to established businesses.

An example is its range of brick, block, paver and retaining block-making machines, where the company has anything from basic manual types of machines, elec-

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tric, hydraulic and large ride-on automatic egg layers to large static manual, automatic and fully automatic machines with elevator and de-elevator, finger cart, curing rooms and packers. These machines can produce 7 000-250 000 stock bricks, 5 400-162 000 pavers, 4 000-140 000 maxi bricks and 1 440-40 000 15,24cm (6”) hollow blocks per nine-hour shift.

Revaro Concrete Equipment also supplies all the additional equipment and machinery needed to set up an entire production plant and the loaders and forklifts to move materials. The product ranges available include:

• Br ick, block, paver and retaining block-making machines.

• Kerb-making machines o Able to manufacture all South African kerb stones up to 1m in length. They come in one- or three-head automatic o Capacity: 400-1 500 per day • Lintel and hollow-core slab plants o Lintel capacity: 2 500-50 000 per day o Hollow-core capacity: 600-1 200 per day • Pipe- and pole-making machines o Pipe sizes: 250-3 000mm o Pole sizes: Various • Roof tile plants o Hydraulic pressed or extruder roof tile machines o Capacity: 500-20 000 per day • Mixers and batchers o Batchers are able to batch up to four different aggregates automatically with PLC. This eliminates maintenance from boom scrapers o Pan, twin-shaft and large-volume planetary mixers  Capacity: 350-500L, 500-1 500L and 1 500-3 250L • Cone, jaw and hammer crushers

• •

•

•

•

•

•

•

o Crushing machines and plants are especially important in the precast industry as they allow manufacturers to re-use concrete, thereby reducing waste and operating costs Trolleys and stackers Composite and plywood pallets o Revaro composite production pallets are produced from a blend of proprietary high-quality composite materials and fibres and are the most significant breakthrough in production pallets o Local and imported pine plywood of the highest quality, treated with Revaro wax oil and sealed with phenolic waterproof glues Roll-forming and concrete roof tile machines o Roll-forming is the process of continuously bending steel coils by passing them through consecutive sets of rollers to a desired shape for use in building and construction o Concrete tile machines are extremely versatile to manufacture all South African roof tiles with the use of interchangeable moulds PC wire and strand o PC wire and strand is mainly used in the reinforcement and production of pre-stressed concrete.

Corrugated steel sheeting o Steel coils, meaning sheet metal in coil form, for use in roll-forming Forklifts o Rough terrain, all terrain and standard, from 2-10 tons o Standard, from 2-35 tons Loaders o 1,2-5-ton wheel-loaders o 2-ton telescopic wheel-loaders Excavators o 0,8-6-ton excavators

(Top left): Revaro Concrete Equipment supplies equipment to manufacture almost every element of a house.

(Left and above): Precast concrete unit manufacturing machines.

| PRODUCTS |

SPUN CONCRETE POLES FOR POWER TRANSMISSION AND DISTRIBUTION Transmission and distribution powerlines in suburban and rural areas need poles that can withstand harsh environments, inclement weather and vandalism, in order to ensure the continuous supply of electr icit y. Rocla’s spun concrete transmission and distribution poles are well suited for the exacting requirements of electrical distribution line construction.

The durable, maintenance-free spun concrete poles are exceptionally strong through 360°, whereas normal cast concrete poles have a major and minor load axis. The unique centrifugal manufacturing process gives a uniform densely compacted concrete along the whole length of the pole. This gives the Rocla spun concrete pole extra strength properties, not found in cast concrete poles.

Spun concrete transmission and distribution poles offer a cost-effective solution due to small servitude requirements, simple and economic funding methods and

a quicker installation turnaround time.

They offer a durable, long-term solution with minimal maintenance. Rocla spun concrete pole systems are Eskom-approved and have been tested at Eskom’s Rosherville Testing Station.

A bonus for the farming community because of the systems’ small servitude requirements is that they are well suited to intensive farming on high-value land.

Rocla offers a variety of pole lengths in single-, jointed- and double-pole solutions, and Rocla’s engineering technical team are able to customise spun concrete pole solutions to meet specific customer sizing requirements, as well as desig n and manufacture products for non-standard applications.

Spun concrete poles offer a lifespan of over 50 years and Rocla manufactures a range of concrete pole solutions for electrification, reticulation, telecom masts, lighting, security monitoring and stadium use.

NEW CEILING TILES

unique environmental properties of natural gypsum,” says Paul Louw, product category manager: ceiling solutions and metals.

“The new Gyprex L ceiling tiles are a great option for areas that require fit-for-purpose level vinyl ceiling tiles. Additionally, the tiles are available in two types of finishes, namely white vinyl or fissured facing.”

Using the new cost-effective lay-in solution, a Gyprex L ceiling tile will not sag when correctly installed and is robust enough to be scratch- and dent-resistant.

Manufactured with a 100% recyclable gypsum core, the low-maintenance tiles are easy to clean and provide a degree of sound insulation.

Saint-Gobain’s Gyproc division recently launched a new product in the ceilings category: the lightweight Gyprex L ceiling tile. Targeted primarily at commercial institutions such as off ices, education, healthcare and retail developments, the new Gyprex L tiles, locally manufactured in 6,4mm thickness, are easy to handle and install.

“Gy proc Sout h A fr ica’s range of ceiling systems provide some of the most versatile design and aesthetic options in the market, while incorporating the

| TECHNICAL |

STRONG FOCUS ON SUSTAINABILITY IN CCSA’S NEW FULTON’S CONCRETE TECHNOLOGY The 10th ed it ion of Fulton’s Concrete Technolog y, commonly regarded as the South African “concrete bible” and globally recognised as a definitive handbook on concrete, was launched by Cement & Concrete SA (CCSA) on 10 June this year.

It comprises 37 chapters and features topics such as materials and mixes, concrete properties, manufacture, site practice, quality control and testing, as well as special concrete and techniques. It is a hardcover book with a searchable electronic flashcard available to the public, available to members of CCSA at a discounted rate.

Bryan Perrie, CEO of CCSA, says several years of intensive research and co-ordination preceded the publication of the revised and updated Fulton’s Concrete Technolog y, which was last published in 2009. The authors of the different chapters, selected to offer a combination of experienced and young professionals, wer e d r aw n f r om a w ide r a n g e of backgrounds: academics and researchers, concrete producers and manufacturers, construction material specialists and consulting engineers.

Enormous resource “The 2021 Fulton’s contains a wealth of new reference material and – with 10 new chapters – represents a significant update on the previous edition. For example, there’s a strong emphasis on sustainability – an issue of global concern in all sectors of industry,” explains Perrie.

He says that the knowledge, experience and insights in concrete technology in the

latest issue are, as usual, directed at South African conditions and will be welcomed by concrete practitioners and lecturers in diverse fields, as well as students, for whom it is a prescribed reference work.

The f irst three editions (1957-1964) were written by Dr Frederick Sandrock Fulton, then director of the forerunner of the Portland Cement Institute, which now has Cement & Concrete SA as its latest incarnation.

Special concretes “Subsequent editions of the book were multi-authored and multi-faceted because, as concrete evolved into a much more complex material, it became extremely difficult for a single author to deal in suitable depth with all aspects of modern concrete technology. The fact that more chapters than any other in the new edition deal with special concretes and techniques illustrates this technological expansion,” adds Perrie.

The resource was edited by Mark Alexander, emeritus professor of civil engineering and senior research scholar at the University of Cape Town. A past president of the International Union of Laboratories & Experts in Construction M ater ia ls, Systems a nd St r uct ures, Alexander is the author of several respected

concrete technology publications and his experience has been widely used in a consulting capacity both here and abroad.

He says the latest edition of the book comes at a time of unprecedented change and challenge in the world, including SA. “Tremendous demands will be made of professionals in future to address issues such as sustainability of concrete construction, impact of climate change and population growth. This makes the need for authoritative, relevant, accurate and up-to-date information on concrete – which remains the world’s most-used construction material – absolutely vital.

Sustainability first “Sustainability is essential to produce concrete in a manner that meets the needs of the population without irreparably damaging the planet. Therefore, the sustainable theme is present throughout the book, with a ‘sustainability focus’ in all pertinent chapters,” adds Alexander.

CCSA members can order a copy of the new Fulton’s Concrete Technolog y by e-mail: info@cemcon-sa.org.za and non-members can purchase copies from www.bidorbuy.co.za. Further details are available from the CCSA Information Centre on tel: (011) 315 0300.

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| TECHNICAL |

(Below): Sprinkling fine material with a sieve.

(Below): Paver silhouettes were visible on the base course after the removal of the pavers.

The first in a series of experiments on how the use of geotextiles affects clogging in permeable interlocking concrete paving (PICP) installations was run by the Civil Engineering Department of the University of Cape Town (UCT) during May/June.

Supervised by Prof Neil Armitage and civil engineering Master’s student Motlatsi Monyake, the day-to-day execution of the research work was conducted by fourth-year civil engineering student Josh Blackshaw, with additional input from Monyake.

“The primary goal of this and the research to come is to provide South African PICP users and designers with solid recommendations on PICP design based on empirical evidence, rather than what we think the answers are,” said Armitage.

Worthwhile experiment “We were feeling our way with this initial experiment and, as could be anticipated, the results were by no means conclusive.

Although we didn’t achieve our chief objective, namely to get one or more of the research cells clog completely, the experiment certainly proved worthwhile.

If nothing else, it provided a stepping-stone for further research.

“But it did more. For example, it revealed that no matter how good the

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UCT CONDUCTS EXPERIMENT ON GEOTEXTILE CLOGGING IN PICP infiltration properties of geotextiles, they do cause some loss of infiltration capacity.

Moreover, the choice of geotextile seems to make very little difference to the rate of clogging.”

The laboratory testing involved four cells (A-D) which mimicked live PICP installations. Each cell comprised the following: a 200mm sub-base layer of 1925mm aggregate; a 50mm base course of 9mm aggregate; a 50mm bedding layer of 2-6mm aggregate, and grit stone of 2-3mm for insertion between the pavers. Cell A was devoid of a geotextile layer, while cells B, C and D had different geotextiles installed between the base course and the bedding layer. These were: Fibretex F25 (heatsealed/treated) – cell B; Kaytech Bidim A1 (needle-punched/non-woven geotextile) – cell C, and Kaytech Kaytape S120 (woven geotextile) – cell D.

Careful assessment “We chose the Fibretex F25 because it’s similar to Inbitex, which forms part of the Aquapave standard PICP package.

Everyone in SA knows Bidim, so it was an obvious choice. For cell D, we wanted a geotextile with large openings, which was why we opted for Kaytape.

“All the cells followed the same drop-off curve and there was no discernible difference in behaviour between the geotextile and nongeotextile cell. By the end of the experiment, inf iltration rates had declined on the following basis: cell A by 83,6% from 12 861 to 2 106mm/hr; cell B by 94,5% from 11 523 to 637mm/hr; cell C by 84,7% from 10 363 to 1 590mm/hr, and cell D by 91,7% from 10 670 to 889mm/hr.” (See Tables 1 and 2.)

Using a sieve, loadings of fine material (pollutant) recovered from Blue Route Mall and previous PICP laboratory experiments

| TECHNICAL |

were sprinkled onto the paved surface at an initial rate of 100g/m² per week.

In addition, 500mm/m² of simulated rainwater per week was sprayed onto the surface with a watering can at 100mm/m² per day from Monday to Friday. Notionally based on Cape Town’s annual rainfall, the purpose of the water was to wash the material into the gaps between the pavers and help migrate it to the geotextile.

Neither the fine material nor the water was applied over weekends, thereby imitating dry periods in the real world. Some fine material remained on top of the pavers after the first watering, but during the course of the week, it was all infiltrated.

Base test Before the first fine material and waterloading took place, a base inf iltration test was conducted using a single-ring inf iltrometer, the standard American test method. It is more accurate than the Modified Swift Test and is therefore better suited to laboratory work. After the base test, infiltration tests were run at the beginning of each week. Some intermediary testing was also done.

“The infiltration rate dropped off week by week and, as predicted, the decline was rapid at first. However, after the second and third weeks, it became obvious that complete blockage wasn’t going to happen in the allocated five-week period. So we added a lot more material during the last two weeks, upping the loading to 200g/m² in the fourth week and to 500g/m² in the fifth,” said Armitage.

Week/ Period Week/ 1 Period 21 3 24 35 4 5

Cumulative Load (g/m²) Load 0Cumulative (Base infiltration) (g/m²) 100 0 (Base 200 infiltration) 100 300 200 500 300 1000 500 1000

Because there was little discernible difference in the decline of infiltration performance between the geotextile and non-geotextile cell, it indicated that most of the blocking was taking place between the pavers. This proved to be the case when the pavers were lifted and the bedding

layers removed at the end of the fifth week.

Only a very thin layer of loading material had been deposited on all three geotextiles.

Infiltration tests were run directly on all of them which demonstrated they were not blocked at all and that the drop-off in performance was minimal.

“Stone grit and fine material between the pavers had fallen onto the bedding layer.”

Interesting results When the pavers were removed, it was also apparent that the stone grit and fine material between the pavers had fallen onto the bedding layer. This was because the fine material was granular and had a very low clay content. Moreover, the gaps between the pavers were comparatively narrow – another reason most of the blo c k a g e o c c u r r e d b et we en t he m .

However, once the pavers had been lifted, their silhouettes on the bedding layers were visible in patterns which were identical across all four cells.

“We’re look ing at mak ing several changes to our next experiment, with the aim of actually inducing failure in one or more of the cells. We intend reaching a point where we achieve what we witnessed at Steen Villa, a residential complex in Cape Town where the geotextile in the PICP installation was completely blocked.

“We’ll probably start with a material loading of 500g/m² because in the first experiment, we saw that the bedding layers have enormous capacity for absorbing fine material. We could have pumped in a lot more material without affecting the openings between the stone grit and the bedding layer.

(Above): A water infiltration test on the exposed geotextile using a single-ring infiltrometer.

Table 1. 5-week infiltration tests of PICP cells

Infiltration Capacity Infiltration Capacity Infiltration Capacity Table 1.

5-week infiltration tests of PICP cells (mm/hr): A (mm/hr): B (mm/hr): C Infiltration Capacity Infiltration Capacity Infiltration Capacity 12861 11523 10363 (mm/hr): (mm/hr): (mm/hr): 10912 A 8574 B 8574 C 12861 11523 10363 7502 7871 5487 10912 8574 8574 7009 5649 3311 7502 7871 5487 2568 2705 1840 7009 5649 3311 2106 637 1590 2568 2705 1840 2106 637 1590

Infiltration Capacity (mm/hr): D Infiltration Capacity 10670 (mm/hr): 9059 D 10670 6117 9059 4052 6117 2182 4052 889 2182 889

Table 2. Infiltration capacity reductions after 5-week loading test

Infiltration capacity reduction (mm/hr) Infiltration capacity reduction (mm/hr)

Infiltration Capacity capacity Infiltration Capacity Infiltration Capacity Table 2. Infiltration reductions after 5-week loading test (mm/hr): A (mm/hr): B (mm/hr): C Infiltration Capacity Infiltration Capacity Infiltration Capacity 83,6% 94,5% 84,7% (mm/hr): A (mm/hr): B (mm/hr): C 83,6%

94,5%

84,7%

Infiltration Capacity (mm/hr): D Infiltration Capacity 91,7% (mm/hr): D 91,7% PRECAST | ISSUE THREE | 2021

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| TECHNICAL |

“Increasing the application of water from 500L to 2 000L per week is also being contemplated. In the real world, PICP installations normally handle water from beyond the permeable paved area and it’s quite common to have run-on factors of three-to-one. What’s more, additional

(Above): Simulated rainfall using a watering can.

water will be needed to mobilise the additional fine material,” said Armitage.

(Above): A partially exposed geotextile membrane showing minimal fine material deposit.

Vehicle damage “One of the differences between lab testing and what we see on site is the lack of vehicle loading. Real-life paving is subject to vehicle

traffic, with its attendant braking and acceleration. This sends shock waves through the sub-base layers and causes the pavers to open and close slightly. These factors mobilise the migration of fine material at a faster rate than simply applying water, so we’re looking at simulating vehicle-loading by applying some sort of vibration, which is yet to be decided.

“We’ve recruited five more fourth-year students who’ll be adopting pieces of this project during the coming year under the guidance of Motlatsi, whose involvement forms part of his Master’s degree. One will carry on with Josh’s work and the others will look at software and different guidelines from around the world. We’ll approach it from different angles and try to come up with something we can defend.

“As is often the case, one learns more by the experiments which don’t work than those that do. Even though our research so far is inconclusive, our understanding of the processes involved is improving all the time,” said Armitage.

“The primary goal of this and the research to come is to provide South African PICP users and designers with solid recommendations on PICP design based on empirical evidence.”

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| TECHNICAL |

The installation quality of waterproofing membrane is vitally important because the integrity and continuity of the membrane determine the performance and durability of pa rk i ng deck s, says Ch r istopher Norbur y, techn ica l sa les consu ltant for abe Construction Chemicals in the Western Cape. The company has supplied membranes and sealants for hundreds of such structures throughout SA “Structural parking decks typically consist of reinforced concrete slabs over precast supporting units. Unlike covered structures, concrete parking decks are exposed to aggressive elements and prone to deterioration, such as spalling, scaling, cracking and delamination. The decks are also subjected to dynamic loading conditions and destructive chemical attacks.

Costly investments “Parking decks are costly to build, repair and replace, so water management is vital. Designing, installing and then testing waterproof ing systems are the keys to diverting water away from the structural elements. Water is the major cause of concrete deterioration and steel rusting, which is why abe’s protective waterproofing membranes are so widely used. Flood testing using ASTM D595798 ‘Standard Guide for Flood Testing Horizontal Waterproofing Installations’ is

WATERPROOFING ADDS DURABILITY TO CONCRETE DECKS “Structural parking decks typically consist of reinforced concrete slabs over precast supporting units.” a good method to verify the waterproofing membrane,” says Norbury.

He notes that abe’s double-layer waterproofing system has proved particularly successful in wide-ranging applications.

The system typically comprises abe’s Index 4mm membrane, followed by an Index 3mm membrane, laid with staggered side and end laps. The 4mm membrane is fully sealed by torch fusion to the primed substrate, as well as the overlaying 3mm membrane. abe’s popular Index range comprises elasto -plastomer ic poly mer-bitumen waterproofing membranes, manufactured from distilled bitumen and modified with elastomers and plastomers. The product is (Above, left and below): Two stages of abe Index membrane laying to ensure a fully waterproofed, completed parking deck.

reinforced with a non-woven, continuous extruded spun-bond polyester fabric which is rot-proof.

Good options Norbury says that for parking decks, the blacktop is often the cheapest wearing surface, but in hot climates this is not always the best long-term solution. In such cases, other trafficable systems should be considered, such as paving over a sand bed that includes a drainage layer.

Other products supplied by abe for waterproofing parking decks include VIP QuickSeal, a polyurethane/polyurea product that provides flexible, seamless, hard-wearing protection. It is applied by a high-pressure rig, can cover 1 000m² per day and cures so rapidly that light traffic can be handled in under five minutes.

Jointing products include the renowned range of imported Dowsil silicone joint sealants ( Dowsil DC 890SL , Dowsil DC888 and Dowsil DC813), as well as flexothane G and HS elastic polyurethane sealants, durakol GHM high-modulus polysulphide sealants and durasheet polyethylene semi-rigid joint fillers used for forming expansion joints or as backing material for joints. Durajoint flexband, a high-performance waterproofing bandage comprising thermoplastic elastomers, is also frequently specified for decks.

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| TECHNICAL |

WATER QUALITY FOR CONCRETE MANUFACTURING With water in short supply in many parts of SA, concrete producers could face increasing pressure to use water from sources other than municipal tap water in future, says John Roxburgh, senior lecturer at the School of Concrete Technology of Cement & Concrete SA (CCSA).

“However, the quality of concrete may be adversely affected by using poor-quality water,” he warns.

He says likely consequences could include: • Alteration of the concrete’s setting times.

• Increase in water demand.

• Entraining of excessive air.

• Changes in the concrete’s strength gain characteristics.

• Degradation of the hardened concrete.

• Corrosion of the reinforcement in the concrete.

• Staining and production of efflorescence.

“Mixing water makes up about 8% of the total mass of concrete, so the proportion (Top): Seawater may be used for concrete – but only when it will not contain steel reinforcement or other embedded metal.

(Right): John Roxburgh, senior lecturer at the School of Concrete Technolog y of Cement & Concrete SA (CCSA).

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of impurities in the mixing water compared with the mass of cement is typically very low. Nevertheless, non-potable water should always be assessed for suitability for use as mixing water in concrete. The limits to the quantities of impurities in the water should be checked against the requirements of the SA National Standards’ SANS 51008, which contains specifications for sampling, testing and assessing the su it abi l it y of water for concrete production,” says Roxburgh.

He cautions that when assessing the suitability of water of unknown quality, both the composition of the water and the proposed application of the concrete should be considered. In general, the suitability of water for concrete depends on its origin.

The following types could be encountered: Potable water is suitable for use in concrete and needs no testing.

Water recovered from processes in the concrete industry will normally be suitable, but must conform to SANS 51008.

Water from underground sources

may be suitable, but must also be tested and assessed in accordance with the requirements of SANS 51008.

Natural surface water and industrial waste water may be suitable for use in concrete, but this, too, requires testing in terms of SANS 51008.

Seawater or brackish water may be used for concrete that will not contain steel reinforcement or other embedded metal.

For concrete with steel reinforcement or embedded metal, the permitted total chloride content in the concrete is the determining factor.

Sewage water is not suitable for use in concrete.

Concrete enemies “Some common substances deleterious to concrete and found in water are chlorides, sulphates, acids, alkalis, humic matter, oil, algae, sugar and detergents. There are many more and SANS 51008 should be consulted,” says Roxburgh.

“Water for use in concrete must conform to the requirements for preliminary assess-

| TECHNICAL |

made with distilled or de-ionised water.

“The mean compressive strength at seven days of the concrete, or mortar specimens prepared with the water, must be at least 90% of the mean compressive strength of corresponding specimens prepared with distilled or de-ionised water,” advises Roxburgh.

ment and for chloride, sulphate and alkali contents. The water must also conform to either the chemical requirements for harmful contamination or the requirements for setting time and compressive strength.

“The sulphate content of the water mustn’t exceed 2 000mg/L. This limit should always be assessed with regard to sulphate content within the aggregate and cement. If alkali-reactive aggregates are to be used in the concrete, the water must be tested for its alkali content. If high, the water may be used only if it can be shown that actions have been taken to prevent deleterious alkali-silica reactions,” he explains.

(Above): Poor-quality water could affect the quality of concrete, says CCSA.

Important tests Regarding harmful contamination, initial qualitative tests for sugars, phosphates, nitrates, lead and zinc must be carried out.

If the qualitative tests are not performed or show a positive result, either the quantity of the substance concerned must be determined or tests for setting time and compressive strength be performed.

“The initial setting time obtained on specimens made with the unknown water shouldn’t be under an hour and shouldn’t differ by more than 25% from the initial setting time of specimens made with distilled or de-ionised water. The final setting time shouldn’t exceed 12 hours, nor should it differ by more than 25% from the fi nal setting time obtained on specimens

Proper testing When sampling water, volumes of at least five litres must be used, taking the possible effects of seasonal fluctuations into consideration. The water must be tested within two weeks of sampling.

“SANS 51008 also provides methods for the tests required, applicable frequencies for testing and detailed requirements for the use of water recovered from processes in the concrete industry,” says Roxburgh.

“When sampling water, volumes of at least five litres must be used.”

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| PROJECTS |

Seven Roman-inspired precast concrete arches manufactured by CMA member, Cape Concrete, for m t he pr i ncipa l architectural feature of a new winery at Bacco Estate, a recently established wine estate fringed by spectacular mountain scenery on the outskirts of Paarl.

Due for completion in time for 2022’s January harvest , the winery is a threetiered structure comprising: a 1 000m² basement/cellar, a double-volume 1 100m² ground-floor which houses a 700m² tank processing area; and a 400m² tasting section. The structure also includes a 200m² first f loor administration section and a triple-volume glazed atrium.

“We were presented with the basic equipment layout by the consulting process engineer, Gerard de Villiers,” said architect A nthony Stricker of A nderson Perr y Partnership Architects (APPA). “It included the tank elements and wine barrels and gave us a footprint which formed the basis for our layout.

“A lt hough funct ion played a key role in our design, we were inspired by the scale, structure and symmetry of Roman architecture, but without the ornamental flourishes associated with styles of classicism. This was at the request of the

estate’s owner, Nathan Jankelowitz, who wanted the building to be a visual reference of the contemporary ‘Super Tuscan’ wines produced by the estate. He also requested that the arches be constructed from precast concrete because of its superior finishes and ease of construction.”

Seven arches Cast in three sizes, all seven arches comprise precast curved sections supported by two vertical precast wall panels. The front of the building is dominated by two of the three largest arches as modern-day portcullises, which, at their highest point, rise to an imposing 10,5m.

“We made these arches larger because they form the structure’s public portals.

Moreover, they encase glass panelling and doors, and their greater depth enabled the glazing to be recessed for sun protection,” said Stricker.

Precast arches set the tone

FOR NEW WINERY The panels of the largest arches weigh 15 tons apiece and measure 7,8m (height) x 2,59m (depth) x 280mm (thickness). A 430mm portion along the front ends of the larger wall panels were stepped down to a thickness of 200mm to match the thickness of the curved sections, which weigh 12 tons and measure 200mm (thickness) x 2,59m (depth) x 5m (internal diameter).

Wine-tasting One of the large arches provides access to the double-volume reception hall and winetasting section and the other provides entry to an extension of the hall. Both spill out onto an entrance patio at the front of the building. The third large arch is positioned parallel to the f irst in the wine hall’s opposing gable wall elevation and provides access from the hall into an open courtyard.

Besides the south-western arch of the wine-tasting hall, the courtyard is flanked (Above): The second entrance arch.

(Left): The two entrance arches.

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| PROJECTS |

Before the design elements were finalised, Cape Concrete was approached by APPA to establish whether precast arches were a feasible option. Cape Concrete factory manager, Johan Nel, said not only were they doable, but the off-shutter f inish achieved with precast concrete was difficult to achieve with in-situ casting.

Perfect finishing “It was very important that the finish on the inner side sides of the arches be glasssmooth and we used two concrete mix designs: the panels were cast with a 40MPa mix, whereas the arches were produced with a 50MPa self-compacting mix because it flows easily and expels air bubbles.

(Below): A view from the south side of the winery through the two dispatch store arches and the wine-tasting hall arches beyond and the architect’s perspective of the completed structure.

by a 300m² finished goods dispatch store at the south-western end of the structure and the wall of the ground-floor processing section, which was built as a series of redbrick mini-arches with glazed infills.

The dispatch section accommodates two of the mid-sized arches installed on opposing gable elevations. The panels for these arches measure 7,2m (height) x 800mm (depth) x 200mm (thickness) and the curved sections measure 200mm (thickness) x 800mm (depth) x 5m (internal diameter). The arch which faces onto the courtyard has a brick infill to match the arch motif of the production section. The other has an insulated timber sliding door which provides vehicular access to the store.

Feasible option The third mid-sized arch also has an insulated timber sliding door and is positioned at the back of the building to provide a service/vehicular entrance to the grape-sorting section.

The smallest arch was installed inside the building and forms one of the four elevations on the south-western side of the glazed atrium. Its panel measurements are: 6,5m (height) x 450mm (depth) x 200mm (thickness) and the curved section came in at: 200mm (thickness) x 450mm (depth) x 5m (internal diameter). This arch was glazed to match the glazing in the rest of the atrium.

“We were inspired by the scale, structure and symmetry of Roman architecture, but without the ornamental flourishes.”

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“The moulds for the curved sections were made in-house, which is an art in itself requiring great skill.”

“The moulds for the curved sections were made in-house, which is an art in itself requiring great skill. The wall panels were cast on flat steel beds and we only had to manufacture the sides of the two moulds.

The smooth off-shutter finish is located on the inner sides and on the two outer edges of the panels and curved sections. The outer surfaces were given a very good steel-floated finish, which also required considerable skill to achieve,” said Nel. Structural engineer, Donovan Webber of Sut herland Eng ineers, sa id Cape Concrete achieved excellent finishes on all the arch components. “Casting them on site would have been very difficult and we couldn’t have achieved the curving with the same degree of accuracy, let alone the smooth finishes which were realised.

Different designs “We designed the smaller panels with grouting ducts, as opposed to the larger panels which were cast with stub columns and starter bars. However, the top of all the panels were imbedded with starter bars for tying into the curved sections.

Project team Architects: Anderson Perry Architects (APPA) Structural engineers: Sutherland Main contractors: WBHO Construction Process engineers: Gerard de Villiers Precast concrete supplier: Cape Concrete Quantity surveyor/Client: JMHT/Nathan Jankelowitz “Initially we looked at casting the arch sections in segments, but it would have made the installation somewhat more complicated. It would also have required on-site staging to support the segments and would have slowed up the project, so a decision was made to cast them in one piece.

“The smaller panels were lowered onto starter bars which had been cast into the footings and the concrete floor. Once in position and aligned, the panel ducts were filled with grout. The curved sections were then lowered onto the panels, seated over the starter bars and grouted through the ducts which had been cast into the curved sections.

Living dream “The largest panels were lowered onto the blindings of the arch foundations and were aligned using props and steel shims to ensure that once they were placed onto the panels, the curved sections would fit perfectly. The pouring of the foundation concrete only took place once the panels had been aligned and the curved sections grouted,” said Webber.

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Civil engineer: Kantey & Templar Consulting Engineers Fire & Mechanical Engineer: Ekcon Structural Engineers

Commenting on the project, Jankelowitz said establishing a “Super-Tuscan” styled wine farm had been a long-held dream.

“I decided to build a wine farm from scratch and bought the land from a property consortium in 2013. We currently have 15ha under French Bordeaux and Italian varietals and will be planting another 15ha from 2022. This will give us a harvest yield of 200 tons a year, which places us firmly in the boutique wine-farm category. We will be selling into both the local and export markets and will mature the wine in barrels for two to four years.”

(Top): One of the large arches is lowered into position on the main entrance arch.

(Above left): The main entrance arch.

(Left): The two entrance arches.

Tel +27(0)11 864 8842 or +27(0)11 900 8013 Fax 086 607 5650 Email: Gripplesa@netactive.co.za Website: www.gripple.com

| PROJECTS |

Massive logistics warehouse

BUILT WIT

Solar City, Cape Town is where a massive 37 000m² warehouse was completed at the end of June for a global transport and logistics company.

Situated on a corner site flanked by one of the runways of Cape Town International Airport and the N2 highway, the structure was built using precast columns and tiltup panels supplied by precast building specialist Superstruct. The warehouse has two main sections: a 30 000m² logistics section and a 7 000m² cross-dock facility.

Marius van den Berg, MD of Berg Partnerships, the development’s project managers, says that four to six weeks were saved by using the precast elements.

“Besides in-situ construction being slower than its precast equivalent, we were able to begin casting before approval had been granted, which also saved time,” he says.

Heavy lifting Forty-one different column configurations in heights of 4,7m-17,2m and varying widths and thicknesses were cast. The (Top left): The cross-dock section flanked by one of the western elevations and the smaller southern elevation.

(Top right and left): The warehouse under construction adjacent to the N2 highway.

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| PROJECTS |

WITH PRECAST CONCRETE (Left): Some of the panels inside the northern elevation of the cross-dock section and some of the 17,2m columns in the warehouse’s logistics section.

panels are extremely large, their 9,6m (width) x 6,155m (height) being close to the outer limit for a panel thickness of 150mm, which was used on this project.

“Lifting and placing of panels as large as these is an operation which requires careful planning and execution,” says Bruere Visser, managing director of Superstruct.

“The placement of lifting anchors in the panels must be accurately calculated to avoid cracking during installation, a process which must be as brief as possible.

“Therefore, to minimise any damage during installation, we worked with numerous casting beds so that all the precast elements could be cast as close to the installation points as possible. Mobile cranes with loading capacities of 90-140 tons were used to lift the columns and panels off the casting beds into their final positions.”

Multi-purpose Superstruct’s columns prov ide three support functions: for the panel walling, some mezzanine flooring and for the roof’s steel structure. They were cast with starter bars for meshing with the column-base

further alignment adjustments were made immediately after the foundation concrete had been poured.

All the panels were lowered onto the column bases at each panel end and were attached to the columns with steel brackets.

Besides providing the building’s perimeter walling, the panels retain the sub-grade soil under the flooring to depths varying from 600mm-2,075m.

rebar and HD bolts at the top end for tying into the structural steel.

All the blindings were checked for levels before the columns were placed, which – once done – were shimmed to the correct height and plumbed to the correct alignment. Where necessar y,

“The warehouse has two main sections: a 30 000m² logistics section and a 7 000m² cross-dock facility.”

Docking panels The warehouse has six elevations; the southwestern corner is recessed and therefore carries two additional elevations. Fortythree docking panels were installed on the northern elevation over its 413m length. All 9,6m wide, they were cast in heights which varied from 6,7-8m. Steel dock houses were fixed and built in front of the panel openings once the latter were securely in position.

A further 26 docking panels were installed on the narrower of the two southern elevations, which is 125m long and provides loading access to the cross-dock section. Also 9,6m wide, these panels were all 6,025m high and their openings were lined with galvanised steel frames to protect

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(Left): The northern elevation with some of the docking bays installed.

the concrete facings against damage from forklifts and other vehicles.

The wider of the two western elevations was installed with seven open-faced panels measuring 8m (width) x 6,8m (height) for vehicle access to the cross-dock section.

The smaller western elevation was built with seven open-faced panels measuring 8m (width) x 6,3m (height) and provides access to the logistics section.

Loose sand The wider of the southern elevations runs for 290m from end-to-end and was built with 30 closed-face panels. Due to its close proximity to the N2 highway, these panels were cast inside the building’s perimeter, unlike in

the rest of the building, where they were cast on the outside of the building. The southern elevation was also installed with 1,3m x 1,3m x 250mm thrust blocks which were cast insitu at the bottom and centre of the panels.

Using kickers, they lend additional support to the panels, which on this side of the building must retain sub-grade to a depth of 2m. The eastern elevation, which is where the administration section is housed, has only two panels. The remainder of the walling on this elevation was built with conventional masonry.

Visser says that one of the major challenges on the site was the loose sand, which required the use of smaller cranes and more casting beds. “Moreover, this was

a tight programme and although we started with the columns, much of the casting had to be done concurrently,” he adds.

“Steel-ribbed sheeting was installed between the panelling and the roof to complete the walling and, in line with client preference, the tilt-up panels were given a cementitious coating for a superior external finish,” says Visser.

Project team Structural engineers: Ekcon Consulting Engineers Project managers: Berg Partnerships Architects: François du Toit Architects Precast concrete elements: Superstruct Quantity surveyors: CHS Quantity Surveyors

| PROJECTS |

Hollow-core slabs used for

CHEMICAL STORAGE FACILITY Hollow-core slabs manufactured and supplied by CM A member Port land Hol lowcore have been used for t he construction of first-f loor decking in a new 3 800m² warehouse for Caprichem, a manufacturer and distributor of a wide range of chemical-based products to more than a dozen market sectors.

Completed in January 2021, the property was designed and project-managed by Structural Survey, which also supplied all the steel used for the project, including insitu columns, steel beams, the roof structure and a steel framework for outdoor shelving, the latter being constructed with hollowcore slabs as well.

Just over 8m long and 200mm thick, and covering a floor area of 1 900m², the slabs were installed by mobile crane at a rate of 220-240m² per day.

“Normally our installation rate’s a lot faster, but in this instance, the building’s roof – which was integral to the stability of the entire structure – had already been installed, which meant our headroom was limited,” says Petrus Theart, divisional manager of Portland Hollowcore.

The slabs span load-bearing walls and steel beams, the latter being supported by the reinforced concrete columns. Each slab was cast with two 50cm exposed core cavities. Y16 rebar was inserted into the cavities of opposing slabs and sealed with concrete.

(Above): The partially completed fi rst floor showing the open cores prior to filling.

(Left): Part of the soffit side of the hollow-core fi rst floor and the hollow-core shelving and walling.

“This gave the entire structure additional strength and rigidity,” says Structural Survey owner Hendri Barnard.

A reinforced, power-floated concrete screed was thrown once all the slabs had been installed. The outdoor shelving was constructed with Portland’s 5m slabs. In

addition, 300m² of twin-decked shelving was mounted adjacent to two hollow-core boundary walls, each just over 30m long and 6m high. The walls were erected with 48 6m² of 5m slabs sandwiched in five layers between steel H-beams, while the shelving panels were mounted on a steel frame attached to the beams.

The wall slabs were cast with a tongueand-groove system so that they could slot into each other without the need for adhesive. However, once a slab was installed, the gaps between the slab and the H-beams at either end were grouted to prevent panel movement.

Barnard believes approximately six weeks were saved by using hollow-core slabs. “Being a warehouse, the floor-toceiling height of the ground-floor section was over 5m, which would have made the installation of scaffolding for in-situ construction impractical, as well as timeconsuming,” he says.

“Just over 8m long and 200mm thick, and covering a floor area of 1 900m², the slabs were installed by mobile crane at a rate of 220-240m² per day.”

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Concrete pavers enhance

CAPE-BASED LIFESTYLE CENTRE Varied use of precast concrete pavers has been made at the Evergreen Lifestyle Village, a new retirement estate developed

by Evergreen Lifestyle in Noordhoek, Cape Town. Six types of pavers, supplied

by CMA member CEL Paving Products, were used at the complex, which comprises 96 two-bedroomed apartments and a lifestyle centre.

The paved areas are extensive, covering 12 0 0 0m². They include 6 70 0m² of driveways and parking areas, a 3 500m² parking basement, 1 500m² of walkways and smaller areas of flowerbed edging and road signage markers.

Completed in February 2021, the driveways and parking areas were paved with

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CEL’s hard-wearing 70mm Brownstone course exposed interlockers, which rest on a 150mm sub-base comprising recycled concrete in a G5 format.

Grey interlockers, 60mm thick, were used for the parking basement which was completed in November 2020, again using the recycled G5 concrete for a 150mm subbase. In addition, 50mm charcoal bond pavers were used for the demarcation of parking bays.

The centre’s walkways were paved with 50mm fi ne charcoal exposed pavers on a 150mm sub-base of G5 material.

CEL’s 73mm De Hoop matt brown pavers make up the flowerbed edging in the driveways and parking sections, while its 70mm White Lava Cobble pavers were inserted to create maintenance-free road signage markers in the same areas.

“We crushed some of the recycled concrete material on site with one of our mobile crushers to a G5 specification. The remainder was imported from our plant,” says Gilles Allies, contract manager of GLC Civils, the project’s civil engineering contractors.

“We specified CEL pavers because their

quality is exceptional and they are generally readily available. If not, they always make a plan to assist and produce the quantities we require. Moreover, CEL’s Brownstone course exposed interlockers are embedded with natural stone, which adds a natural look and feel to the property.”

(Above, from top): CEL’s Brownstone course exposed interlockers; the parking basement, paved with grey interlockers and CEL’s De Hoop matt brown pavers were used for flowerbed edging.

(Left): White Lava Cobble pavers were inserted to create maintenance-free road signage.

Woodwind housing development

CHOOSES TECHNICRETE Technicrete was selected to supply pavers and kerbs for the first 10 phases of the 13-phase high-quality and stylish Woodwind Estate housing development taking place in Centurion, near Tshwane. When completed, the estate will occupy 14 500m² comprising 700 single- and double-storey free-standing and apartment units.

“At each stage of the development of Woodwind Estate, a new tender is issued,” says Werner Bloemhof, quantity surveyor with Raubex Building. “Technicrete was awarded the tender to supply pavers and kerbs based on the quality of its products and cost-effectiveness. “ We’ve received good ser v ice and reliable deliver y scheduling from Technicrete. Its kerbs and pavers offer estates such as Woodwind an aesthetically pleasing f inish and a longevity that’s needed in an estate where there’ll be a large amount of traffic and foot flow-through.”

“Over the first 10 phases, Technicrete has supplied over 60 000m2 of Bondbrick and DZZ interlockers and 6 000m of Fig 8b kerbs. These are mountable kerbs of 300 x 175 x 7mm suitable for medium loading and have a sloped profile in order not to damage vehicles that may need to move onto the pavement or grassed area,” says Luan van der Berg, sales consultant for Technicrete.

The Bondbrick is a cost-effective, traditional paver that offers long durability. It is well suited for estates such as Windwood and was designed with applications such as parking areas and pathways in mind. Sizes include 50mm x 200mm x 100mm, 55 x 200mm x 100m and 60 mm x 200mm x 100mm.

The DZZ interlocking paver from Technicrete forms a continuous interlocking and hard-wearing surface overlay, which offers an extremely elegant finish. Sizes include 50mm x 220mm x 97mm, 60mm x 220mm x 97mm or 80mm x 220mm x 97mm. Colours for both paving blocks and kerbs include slate, terracotta, plum, grey, autumn and tan.

| PROJECTS |

Retention pond upgraded with

TERRAFORCE BLOCKS During the drought of 2017, the Cape Peninsula Universit y of Technolog y (CPUT) Bellville campus began irrigating its green spaces with recycled water from an on-site attenuation pond.

The pond was subsequently found to be losing water and, in compliance with the City of Cape Town’s by-laws for stormwater management, it was upgraded and extended in August 2020.

Westcoa st Ret a i n i ng Sy stem s , a Terraforce-recommended contractor, was appointed by main contractor Ruwacon to build a 420m retaining wall around the pond’s circumference using the Terraforce L12 interlocking retaining wall blocks.

The project was begun by demolishing the existing inlet and outlet structures and the size and depth of the pond were extended. In add it ion to Terraforce retaining structures, gabions were built for erosion protection. New stormwater inlets were installed and a new outlet was built to control stormwater outflows.

Hannes Mostert of Westcoast Retaining Systems says the blocks were installed on a

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750 x 300mm, 25MPa concrete foundation, with drainpipes running behind the entire length of the wall.

“All the blocks were concrete-filled for extra stability and in some places, the wall had to be built higher to protect some tree roots on the edge of the pond,” he says.

With an enlarged capacity, the pond is now better equipped to deal with flooding and droughts.

(Above and right): The revamped attenuation pond lined with Terraforce L12 interlocking retaining wall blocks.

(Below): The new outlet.

| PROJECTS |

A lbert Botha, Ruwacon contracts manager, says rain, sludge and groundwater seepage were some of the challenges during construction.

“The sludge made it difficult to install the concrete foundation of the retaining wall and we had to install a concrete stone pioneer layer before the foundation could be poured, a process which had to take place over several short durations. What’s more, we had to pump out water during the casting,” says Botha.

Once these challenges were overcome, the verges of the pond were re-grassed and a family of ducks introduced to the area. Visually, the pond now showcases a lush, green and peaceful setting that students and animals alike can enjoy. On a functional level, leakage has been curbed and more water will be available during future water shortages.

Attentuation ponds (or wet ponds) are man-made reservoirs built in low-lying areas that control stormwater flows and prevent flooding. They trap stormwater from higher elevations and release it in a controlled manner either into stormwater drainage, or – as in this case – as “grey” water into green spaces for irrigation purposes.

They also prevent erosion and foundational issues in the immediate surroundings and aid in the removal of pollutants such as fertilisers, oils, petroleum and animal droppings. Algae, bacteria and other biological organisms consume the pollutants, largely helping to purify the water.

Project participants

“With an enlarged capacity, the pond is now better equipped to deal with flooding and droughts.”

Consultants: KFD Wilkinson Consulting Engineers Terraforce block supplier: Klapmuts Concrete Project value: R6 400 000

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Multi-faceted cast-stone paving

INTEGRATES WITH FRANSCHHOEK ESTATE Franschhoek’s prest ig ious w ine and premium five-star hospitality retreat, Leeu Estates, has been beautifully enhanced with a comprehensive range of caststone paving blocks, manufactured by the Western Cape’s leading cast-stone manufacturer, Revelstone.

Situated in the Franschhoek Valley just a few minutes away from the picturesque village which bears the same name, Leeu Estates comprises a 23-roomed country house, a meticulously refurbished 19thcentury manor house, guest cottages, historic farm buildings and a boutique winery, set among 68ha of vineyards, landscaped gardens, oak trees and fynbos.

Abutted by the Dassenberg Mountain to the south and the Franschhoek River to the north, this superb private hideaway offers top-drawer comfort, fine dining and platinum service.

Established by international entrepreneur Analjit (BAS) Singh, the estate forms part of the Leeu Collection, which includes (Top): The Jura cobble in a herringbone pattern.

(Right): The Devon double cobble combined with the Jura cobble and Jura straight edge pavers.

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other properties in Franschhoek and Linthwaite House, a 36-roomed country retreat overlooking Lake Windermere in England’s Lake District, as well as Villa Querce in Florence, Italy, a luxury hotel and pristine gardens due to open in 2022.

Long search Singh began his quest for a property in the Franschhoek Valley in 2010, following a visit to see a match during the Fifa World Cup tournament. He knew he had found the

right place the minute he set foot on Klein Dassenberg, a 40ha farm on the slopes of the Dassenberg Mountain and in September 2012, he bought the farm. The following year he bought two adjacent farms, Dieu Donné and Von Ortloff, and amalgamated them into Klein Dassenberg, now known as Leeu Estates. (The name was chosen because “singh” is the Sanskrit word for “lion”, which – of course – is “leeu” in Afrikaans.)

The Leeu Collection made a conscious decision to partner with the best in wine-

| PROJECTS |

“The award-winning Mullineux & Leeu Family Wines are produced in Riebeek-Kasteel in the Swartland wine region.” wines are produced in Riebeek-Kasteel in the Swartland region, about 80km north of Franschhoek. Now that the vines have been established, wines will be produced on the estate, but as house wines, rather than premium products.

(Above): The Jura straight paver.

making, artistic endeavour and fine dining in order to create exceptional experiences for its guests. Thus Leeu Estates has partnered with SA’s leading contemporary art gallery, Everard Read, to create a contemporary gallery on the estate and a sculpture park among its extensive gardens. In addition, the owners of the world-renowned La Colombe restaurant in Constantia have opened La Petite Colombe on the estate.

Partially owned by Singh, the Mullineux & Leeu Family Wines (M&LFW) team has established a wine studio on the estate and its knowledgeable staff guide guests through the finer nuances of premium handcrafted wines. The award-winning

Beauty everywhere Landscape designer Franchesca Watson says Leeu Estates has been established along the principles of Vastu Shastra, a traditional system of Indian architecture wh ich seek s to place t he var ious components of a property in harmonious relation to each other.

“For example, where possible, the v i neya rd s r u n ha rd up ag a i nst t he buildings so that guests connect with the purpose of the historical farm, while the gardens themselves form lush green spaces between the vines. The gardens showcase a remarkable collection of art. This takes the form of monolithic sculptures, as well as smaller pieces that add detail or a special touch. Analjit started acquiring artworks very early on, sometimes with a particular position in mind and at other times buying the pieces and storing them until a perfect stage for them had been found in the gardens. He’s also commissioned artworks around which whole gardens were built as the perfect complementary environment,” says Watson.

“Bokkie Garden was entirely designed around a large central sculpture. Conversely, I commissioned some of the artworks for a specific space, working closely with the artist to achieve a particular vision. With care and over time, the gardens have become art in themselves, in which the fusion of landscape and works of art is complete.”

Paved areas There are many paved spaces interspersed among the estate’s extensive grounds and Revelstone supplied 16 different types of cast-stone pavers. These were installed

between October 2019 and December 2020 for the estate roads, parking areas, patios, pathways and staircases. They were carefully chosen to form a natural extension of the gardens, their colour tones forming the perfect foil for the plants, vines and sculpted art.

Paving contractor Derek Anderson of Highland Paving says this was his most prestigious and diverse paving project to date.

“A naljit Singh and his colleag ues were very far-sighted in their choice of paving, paying particular attention to their installation, with the result that the estate is now an outstanding example of what can be achieved with cast-stone paving. Some of the roads, parking spaces and pathways are high-trafficked areas and the sub-base compositions were designed accordingly,” says Anderson.

(Above, from top): The ravine bullnose and ravine tiles; the Jura straight-edge paver and the Jura straight paver combined with the Jura splayed curve.

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Pedestrian bridge foundations

COMPLETED Gauteng Piling was appointed by main contractor Enza Construction to provide the foundations for a large pedestrian bridge for the Mpumalanga Economic Growth Agency (MEGA) International Fresh Produce Market at Mbombela, a long-awaited new initiative by the trade and investment arm of the provincial government earmarked to spark new economic growth in that region.

The large-scaled market, reported to cost over R1 billion and scheduled for completion early next year, will provide an outlet for small-scale black farmers in the

“Gauteng Piling, which completed the MEGA foundations at the end of May, celebrates 25 years in piling this year.”

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Lowveld who produce most of SA’s fruit and vegetables.

Keoatlaretse Tema, Gauteng Piling’s site manager for the major project constructed on vacant land by Enza Construction, says the 1 260m² concrete foot bridge will link the market to a large taxi rank. The foundations for the bridge required 32 piles 450mm in diameter sunk to depths varying from 8-15m. Steel cages 300mm in diameter provided reinforcement for the concrete piles. “Gauteng Piling had to bring one of its Williams auger diggers from its base in Diepsloot, Johannesburg, to handle this project, for which we also employed local labour,” says Tema.

Gauteng Piling employed straightshafted auger drilling for this project.

During the process, soil and rock were loosened and removed on a continual basis to gradually create the cavity in preparation for concrete piling. A major benefit of this type of drilling is that it can be conducted with comparatively low noise and vibration levels. Furthermore, assembly of the piles is relatively quick and does not require temporary casing.

Gauteng Piling, which completed the MEGA foundations at the end of May, celebrates 25 years in piling this year.

Projects handled by it in 2021 include: • Stabilising a massive, gaping sinkhole near residences in Irene, Centurion.

• The Forest Mansions apartment block in Bramley, Johannesburg.

• The Tshwane University of Technology campus in eMalahleni.

• The Capital Hotel in Mbombela.

• Off ices for the SA Social Security Agency in Mahikeng.

• The new luxury Tree Tops apartment block being developed by Tricolt in Houghton, Johannesburg.

• T he ent r a nc e a nd e x pa n s ion of Cresta Shopping Centre in Randburg, Johannesburg.

• A facility for diving rescue training for the University of Johannesburg’s Medical Rescue students in Auckland Park, Johannesburg.

• Storage tanks for Coca-Cola Beverages Africa in Nigel.

• Expansion of the Africa Floorcare warehouse in Alberton, Gauteng.

(Above): Gauteng Piling in action on a Johannesburg site. The 25-year-old company recently completed the foundations for a large pedestrian bridge for the new MEGA International Fresh Produce Market at Mbombela.

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Monier Coverland (Pty) Ltd AGW Trading T/A Kolbe Blocks Producer Members

Deranco Precast (PtY) Ltd A FICK SEMENTWERKE BK TEL: (022) 913 1921 Corobrik (Pty) Ltd PROVINCE: WC PILLAR: PB Logo

A Fick Sement Werke BK

AGW Trading T/A Kolbe Blocks

ducer Members

AGW Trading T/A Kolbe Blocks

ck Sement Werke BK

Logo

Eagle Roof TilesLtd (Pty) Ltd MVA Bricks cc Corobrik (Pty)

Zittlau Eiendomme (Pty) Ltd t/a

CORESLAB (PTY)Monier LTD Coverland (Pty) Ltd TEL: (087) 232 Zittlau 2462 Eiendomme PROVINCE: LIMPOPO PILLAR: PB/PI

Solid Pave Bricks (Pty) Ltd (Conticrete)

(Pty)MOBICAST Ltd t/a (PTY) LTD

SHUKUMA FLOORING SYSTEMS T/A ZITTLAU EIENDOMME (PTY) LTD TEL: (041) 372 1933 PROVINCE: EC PILLAR: PB

TEL: 086 111 2346 PROVINCE: WC PILLAR: PB/PI Next Page

Beta Tiles (Pvt Ltd

MVA Bricks cc

Conframat (Pty) Ltd MVA Bricks cc

Mobicast (Pty) Ltd

Coreslab (Pty) Ltd

COROBRIK (PTY) LTD TEL: (031) 560 3252 Pavecon Manufacturing (Pty) Ltd PROVINCE: KZN PILLAR: PI

Beta Tiles (Pvt Ltd

AGW TRADING T/A KOLBE BLOCKS Next Page TEL: (041) 406 7900 Deranco (PtY) Precast Ltd PROVINCE: EC Precast PILLAR: PB (PtY) Ltd Deranco

Berts Bricks

W Trading T/A Kolbe Blocks

Solid Pave Bricks (Pty) Ltd (Conticrete) MVA Bricks cc

Coreslab (Pty) Ltd

Beta Tiles (Pvt Ltd Berts Bricks

Portland Hollowcore Slabs (Pty) Ltd

Monier Coverland (Pty) Ltd

Pavecon Manufacturing (Pty) Ltd

Corobrik (Pty) Ltd

Eagle Roof Tiles (Pty) Ltd

Technicrete (Pty) Ltd

Next Page

Portland Hollowcore Slabs (Pty) Ltd

ReMaConLTD Products cc DERANCO PRECAST (PTY)

Eagle Roof Tiles (Pty) Ltd

Pavecon Manufacturing (Pty) TEL: Ltd (041) 463 3338

ReMaCon Products cc PROVINCE: EC PILLAR: PB/PI Coreslab (Pty) Ltd BERTS BRICKS Hollowcore Slabs (Pty) Ltd TEL: (018) 292 Portland 1615

MVA Bricks cc

Next Page

Deranco Precast Hollowcore (PtY) Ltd Portland Slabs (Pty) Ltd

Next Page

SOLID PAVE BRICKS (PTY) LTD (CONTICRETE) TEL: (041) 365 7676 PROVINCE: EC PILLAR: PB

MVA BRICKS CC TEL: (012) 386 0050 PROVINCE: GAUT PILLAR: PI

Pavecon Manufacturing (Pty) Ltd

Berts Bricks

a Tiles (Pvt Ltd

PB – Precast Building

Mobicast (Pty) Ltd

Technicrete (Pty) Ltd

PAVECON MANUFACTURING (PTY) LTD Technicrete (Pty) Ltd TEL: 087 940 3631 PROVINCE: LIMPOPO PILLAR: PI

EAGLE ROOF TILES (PTY) LTD TEL: (044) 874 0290 PROVINCE: WC PILLAR: PB Pavecon Manufacturing (Pty) Ltd

TECHNICRETE (PTY) LTD TEL: (011) 672 1425 PROVINCE: GAUT PILLAR: PB/PI

Vanstone Precast (Pty) Ltd

Vanstone Precast (Pty) Ltd

ReMaCon Products cc

Eagle Roof Tiles (Pty) Ltd BETA TILES (PVT) LTD TEL: (263) 433 3735 COUNTRY: ZIMBABWE PILLAR: PB

s Bricks

C.E.L. Paving Products (Pty) Ltd

L. Paving Products (Pty) Ltd

C.E.L. Paving Products (Pty) Ltd

Vanstone Precast (Pty) Ltd

PORTLAND HOLLOWCORE Vibro Bricks and Paving (Pty) Ltd VANSTONE PRECAST (PTY) LTD SLABS (PTY) LTD Vibro Bricks and Paving (Pty) Ltd TEL: (012) 541 2056/1808 TEL: (021) 972 1111 PROVINCE: GAUT PILLAR: PB/PI PROVINCE: WC PILLAR: PI

Portland Hollowcore Slabs (Pty) Ltd

ReMaCon Products cc

ECOCRETE TRUST TEL: (051) 435 3590 ReMaCon Products cc PROVINCE: GAUT PILLAR: PB/PI

Next Page Cemblocks (Pty) Ltd

Vibro andBricks Paving(Pty) (Pty)Ltd Ltd West EndBricks Cement

C.E.L. PAVING PRODUCTS (PTY) LTD TEL: (021) 905 5998 PROVINCE: WC PILLAR: PI

C.E.L. Paving Products (Pty) Ltd

Cemblocks (Pty) Ltd

West End Cement Bricks (Pty) Ltd West End Cement Bricks (Pty) Ltd

Cem Brick Manufactures (Pty) Ltd

blocks (Pty) Ltd Horizon Brick & Concrete

Concrete Units (Pty) Ltd

VIBRO BRICKS & PAVING (PTY) LTD TEL: (012) 374 5533 PROVINCE: GAUT PILLAR: PB/PI

REMACON PRODUCTS CC TEL: (011) 393 5504 PROVINCE: GAUT PILLAR: PI

Cemblocks (Pty) Ltd

ELEMATIC SA (PTY) LTD TEL: (011) 423 2700 (Cape) (Pty) Ltd PROVINCE: GAUTENG Revelstone PILLARS: PB

Horizon Brick & Concrete Cem Brick Manufactures (Pty) Ltd

Next Page Concrete Units (Pty) Ltd

CEMBLOCKS (PTY) LTD TEL: (014) 538 0311 Horizon Brick & Concrete PROVINCE: NW PILLAR: PB/PI

Cem Brick Manufactures (Pty) Ltd Inca Concrete Products Pty Ltd Next Page

Rocla (Pty) Ltd

HORIZON BRICK & CONCRETE TEL: (012) 943 3701 Shukuma Bricks (Pty) Ltd PROVINCE: N/W PILLAR: PB

Inca Concrete Products Pty Ltd CEMInca BRICK Concrete Products Pty Ltd MANUFACTURERS (PTY) LTD TEL: (051) 433 4479 PROVINCE: F/STATE PILLAR: PB/PI

Brick Manufactures (Pty) Ltd Concrete Units (Pty) Ltd

REVELSTONE (CAPE) (PTY) LTD TEL: (0861) 173 835/ (021) 761 9737 PROVINCE: WC PILLAR: PI

Lategan Cement Works (Pty) Ltd Lategan Cement Works (Pty) Ltd

Next Page

Lategan Cement Works (Pty) Ltd CONCRETE UNITS (PTY) LTD TEL: (021) 386 1923/(016) 362 2236 PROVINCE: WC/GAUT PILLAR: PB/PI

t Page

WEST END CEMENT BRICKS (PTY) LTD TEL: (011) 851 1005 PROVINCE: GAUT PILLAR: PB/PI

WZ Betonwerke

Shukuma Flooring Systems

Revelstone (Cape) (Pty) Ltd

crete Units (Pty) Ltd

WZ Betonwerke

INCA CONCRETE PRODUCTS (PTY) LTD Rocla (Pty) Ltd TEL: (021) 904 1620 Revelstone (Cape) (Pty) Ltd Zittlau Eiendomme PROVINCE: WC PILLAR: PB/PI(Pty) Ltd t/a Solid Pave Bricks (Pty)Rocla Ltd(Pty) (Conticrete) Shukuma Bricks (Pty) Ltd Ltd

Conframat (Pty) Ltd

Next Page

RIETSPRUIT CRUSHERS TEL: (017) 801 1912 PROVINCE: MPUMALANGA PILLARS: PB/PI

WZ BETONWERKE TEL: (057) 733 1626 PROVINCE: F/ STATE

ROCLA (PTY) LTD TEL: (011) 670 7600 PROVINCE: GAUT PILLAR: PB/PI

Shukuma Bricks (Pty) Ltd

Shukuma Flooring Systems

Corobrik (Pty) Ltd

Coreslab (Pty) Ltd

CONFRAMAT (PTY) LTD TEL: (0861) 33 5599 PROVINCE: GAUT PILLAR: PB/PI

L ATEGA N'S CEMENT Shukuma Flooring Systems WOR K S (PTY) LTD SHUKUMA BRICKS (PTY) LTD Zittlau Eiendomme (Pty) Ltd t/a TEL: (021) 873 1154 TEL: (041) 372 1013 PROVINCE: WC PILLAR: PB/PI Solid Pave Bricks (Pty) Ltd (Conticrete) PROVINCE: EC PILLAR: PB Zittlau Eiendomme (Pty) Ltd t/a Solid Pave Bricks (Pty) Ltd (Conticrete)

Next Page

Deranco Precast (PtY) Ltd Next Page

Eagle Roof Tiles (Pty) Ltd

Next Page

PRECAST | ISSUE THREE | 2021

39

Kerneos South Africa (Pty) Ltd Birkenmayer H (Pty) Ltd

| MEMBER LIST |

Chryso Southern Africa (Pty) Ltd

Kobra Moulds B.V.

er Annual Member c

Logo

NON-PRODUCER MEMBERS Non Producer Annual Member Abel Equipment cc

Logo

Birkenmayer H (Pty) Ltd

Chryso Southern Africa (Pty) Ltd

keyePedershaab

y) Ltd

Non Producer Annual Member Abel Equipment cc

Africa (Pty) Ltd

Birkenmayer H (Pty) Ltd Dick King Lab Supplies (Pty) Ltd

CVZ CONSULTING TRAINING TEL: 083 701 4167 PROVINCE: GAUT

ABEL EQUIPMENT CC TEL: (044) 874 1876 Dick King Lab Supplies (Pty) Ltd PROVINCE: EC

KOBRA MOULDS B.V. TEL: 003111 356 2460 COUNTRY: NETHERLANDS

Logo

DICK KING LAB SUPPLIES (PTY) LTD TEL: (011) 499 9400/ (031) 700 2551 PROVINCE: GAUT/DBN

BIRKENMAYER H (PTY) LTD HawkeyePedershaab TEL: (011) 970 3880 PROVINCE: GAUT

PAN MIXERS SA (PTY) LTD TEL: (011) 578 8700/8600 PROVINCE: JHB

Chryso Southern Africa (Pty) Ltd

eos South Africa (Pty) Ltd

Kerneos South Africa (Pty) Ltd

Cement Ann Members

HAWKEYEPEDERSHAAB TEL: 00 459645 4193 COUNTRY: DENMARK

a MouldsAssociate B.V.Members

QUANGONG MACHINES CO LTD TEL: +865 958 679 9557 COUNTRY: CHINA

TERRAFORCE (PTY) LTD TEL: (021) 465 1907 PROVINCE: WC

Concrete Society of Southern Africa

CPI Concrete Plant International

plies (Pty) Ltd

Associate Members

KERNEOS SOUTH AFRICA (PTY) LTD TEL: (011) 444 3090 PROVINCE: GAUT

Address

Logo

AF Consulting Engineers & Associates (Pty) Ltd

embers

CHRYSO SOUTHERN AFRICA (PTY) LTD TEL: (011) 395 9700/ (031) 564 0325/(021) 928 1660 PROVINCE: GAUT/KZN/WC

SIK A SOUTH AFRICA (PTY) LTD TEL: (031) 792 6500 PROVINCE: KZN

AfriSam South Africa (Pty) Ltd

Kobra Moulds B.V.

Dick King Lab Supplies (Pty) Ltd

REVARO CONCRETE EQUIPMENT TEL: (011) 794 8271 PROVINCE: JHB

AF Consulting Engineers & Associates s & Associates (Pty) Ltd

ASSOCIATE Logo LogoMEMBERS

CEMENT MEMBERS

JC Paving Consulting No logo

Concrete Society of Southern Africa

Sekhukhune & Associates No logo Stefanutti Stocks Civils

Concrete Society of Southern Africa

AF CONSULTING ENGINEERS & ASSOCIATES (PTY) LTD CONCRETE SOCIETY OF PROVINCE: JHB Taco Voogt Consulting Engineer CPI Concrete Plant International SOUTHERN AFRICA TEL: (012) 348 5305 PROVINCE: PTA

ASPASA

ASPASA

STEFANUTTI STOCKS CIVILS TEL: (011) 571 4300 PROVINCE: No logoGAUT TACO VOOGT CONSULTING ENGINEER TEL: (012) 669 0125 PROVINCE: PTA

Young & Satharia Consulting

CPI Concrete Plant International

JC Paving Consulting

No logo

British Precast Concrete Federation British Precast Concrete Federation

ASPASASekhukhune & Associates TEL: (011) 791 3327 JC Paving Consulting Stefanutti Stocks Civils PROVINCE: JHB Sekhukhune & Associates Stefanutti Stocks Civils

Next Page

BRITISH PRECAST CONCRETE FEDERATION TEL: +(44) 116 232 5170 COUNTRY: UK

Next Page

No logo

AFRISAM SOUTH AFRICA (PTY) LTD TEL: (011) 670 5500/5752/5972 PROVINCE: GAUT

No logo

CPI CONCRETE PLANT INTERNATIONAL No logo TEL: (02236) 962390 COUNTRY: GERMANY YOUNG & SATHARIA CONSULTING CIVIL ENGINEERS (PTY) LTD TEL: (031) 207 7252 PROVINCE: KZN Logo

JC PAVING CONSULTING Civil Engineers (Pty)TEL: Ltd (011) 431 0727 PROVINCE: JHB Contractor Members Decorton Retaining Systems (Pty) Ltd

SEKHUKHUNE & ASSOCIATES TEL: (012) 346 1945 Friction Retaining Structures (Pty) Ltd PROVINCE: PTA

e

CONTRACTOR MEMBERS

Powergate Construction cc

Valcal International Export cc

DECORTON RETAINING SYSTEMS (PTY) LTD TEL: (021) 875 5155 PROVINCE: WC

FLEXIBLE RETAINING STRUCTURES TEL: (011) 608 4321 PROVINCE: GAUT

VALCAL INTERNATIONAL EXPORT CC TEL: (011) 867 2471 PROVINCE: GAUT

PLEASE NOTE: The above member list was correct at the time of going to print. If your details have changed, please contact Rita at the CMA offices on tel: (011) 805 6742.

40

PRECAST | ISSUE THREE | 2021

IM/02/2021

YOUR PRECAST CONCRETE SPECIALIST PRODUCTS Storm Water Electrical Markers Water Reticulation Outdoor & Building Polymer Products Mining Solutions Kerb Inlet & Road Products Custom Products SERVICES Moulds Drawings

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AUGUST 2021 | No 1151

IN THIS ISSUE: Construction industry is united

For all brand marketing and advertising contact Jenny Justus on 083 450 6052 / 011 883 4627 or jenny@isikhova.co.za

SA product makes it in Spain Shedding light on stormwater purification

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IN THIS ISSUE:

Proudly published by Isikhova Media Address: 10th floor, Metal Box, 25 Owl Street, Milpark, Johannesburg • Tel: (011) 883 4627 • www.isikhova.co.za

DEVELOPMENT ADDRESSES HOUSING SHORTAGES

SHORTAGE SHORTA GES S ADDR AD DRES ESSE SES S HOUSING DEVE DE VELO LOPMENT PMENT

12

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RENOVATING: WHAT EVERY HOMEOWNER NEEDS TO KNOW

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