Precast • Issue 3 • 2019

ISSUE THREE • 2019

R49,00

THE VOICE OF THE PRECAST CONCRETE INDUSTRY

• Robotics growing the industry • Recycled concrete deserves recognition • Extraordinary precast products

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CONTENTS

COVER STORY

COMPANY NEWS

2 ROBOTICS GROWING THE

ROOF TILE INDUSTRY

INDUSTRY NEWS 5

SA CEMENT PRODUCERS APPLY FOR PROTECTION AGAINST IMPORTS

28

16

6

19 MARKETING PRECAST PRODUCTS

29 CAMBRIDGE UNIVERSIT Y

RESEARCHES SELF-HEALING CONCRETE

20 REVELSTONE GEARED

FOR GROWTH

31 REBEL WITH A CAUSE:

HOW SEEKING PERFECTION PAYS

21 PRECAST SANITATION UNITS FOR

MPUMALANGA PRIMARY SCHOOL

34 PRECAST IN BOUTIQUE

WINERY CONSTRUCTION

9

REACHING OUT ON SOCIAL MEDIA

GLOBAL VIEW

9

CMA HOSTS FIRST ECSAACCREDITED WORKSHOP

22 US PICP CONFERENCE ADVICE: DON’T INSTALL IF YOU CAN’T MAINTAIN

10 STANDARDS, CERTIFICATION

AND ACCREDITATION 11 RECYCLED CONCRETE

DESERVES OFFICIAL RECOGNITION

PROJECTS

TECHNICAL 23 QUALIT Y FROM THE BEGINNING

37

24 REDUCING RISKS OF

HANDLING CEMENT

13 WORLD PREMIÈRE OF CON-TEXTURES SCULPTURE

PRODUCTS

26

14 NEW ADMIXTURE PROVIDES

LASTING SEWER PROTECTION 15 EXTRAORDINARY

PRECAST PRODUCTS

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 Postal Address: Post Net Suite 334 Private Bag X 15, Menlo Park, 0102 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 building, 25 Owl Street, Milpark, South Africa Tel: (+27 11) 883 4627 Fax: (+27 11) 783 2677 Website: www.isikhova.co.za Publisher: Imraan Mahomed Tel: (+27 11) 883 4627 E-mail: imraanm@isikhova.co.za Consulting editor: Raymond Campling Tel: 076 297 2775 E-mail: media@mediasavvy.biz

PRECAST | ISSUE THREE | 2019

39 REHABILITATION OF PARKTOWN

STORMWATER SYSTEM 39 PRECAST SPECIFIED FOR

ATTENUATION POND 40 MEMBER LIST

Coastal editorial: David Beer Tel: 082 880 6726 E-mail: david.bigsky@gmail.com

ISSUE THREE • 2019

R49,00

THE VOICE OF THE PRECAST CONCRETE INDUSTRY

Subscriptions/Accounts/ Advertising: Thuli Majola Tel: (+27 11) 883 4627 E-mail: thuli@isikhova.co.za Design and layout: Joanne Brook E-mail: joanne@isikhova.co.za 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© 2019. 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.

Endorsed by:

ON THE COVER Robotics an

are

increasingly

playing impor-

• Robotics growing the industry • Recycled concrete deserves recognition • Extraordinary precast products

tant role in assisting manufacturers to reach ultra-high production speeds with higher-quality products and less wastage. At the forefront of this technology is a company that has been perfecting roof tile manufacturing plants for the past 100 years, ABECE. The Swedish equipment manufacturer is a world leader in producing plants that are approaching nearly 100% efficiency in terms of material usage, reduced waste and high-speed manufacturing.

1

COVER STORY 2

At the forefront of this technology is a company that has been perfecting roof tile manufacturing plants for the past 100 years, ABECE. The Swedish equipment manufacturer is a world leader in producing ultra-high efficiency plants that are approaching nearly 100% efficiency in terms of material usage, reduced waste and high-speed manufacturing.

In South Africa the ABECE range of plants is distributed and supported by

ROBOTICS GROWING Robotics are playing an increasingly important role in assisting manufacturers to reach ultra-high production speeds with higher-quality products and less wastage.

overhangs or push marks and leads to less rejects and damages.

Tight tolerances After the dual servo knife cuts the tile on the pallet at an exact length it moves to the racking station where it is stacked

the country’s own technology leader,

before being moved to the zero zone

PMSA (non-producer member of the

for acclimatisation and automatically

Concrete Manufacturers Association

transported into the hottest part of the

– CMA), a company which holds similar

curing room.

values and standards as its overseas

Even the high precision automated

counterpart. Over the past decade the

racking system is built for speed with

partnership has driven the brand to be-

specialised wheels for faster, more reli-

come a firm favourite in southern Africa

able movement and less jamming. The

with plants operational throughout South

ABECE racking and de-racking systems

Africa and the sub-Saharan Africa region.

are designed to be the most efficient in the world with hundreds of features built

Blink-of-an-eye

into the system to enable high levels of

PMSA marketing and sales manager,

automation. Precise and minimalistic

Quintin Booysen, says the move to

movement results in less jamming and

automation in all, or some, of the opera-

smoother operation.

tions in a plant is a necessity in order to reach and maintain high volume produc-

Curing efficiently for energy saving

tion. ABECE’s modern plants have all the

The process of curing can be from 7

necessary technology to mix and extrude

into place for extrusion of the tile upper

hours to 24 hours depending on the ce-

high quality concrete, but the real need

surface on a high speed ABECE extruder.

ment content of the tile. Once again, for

for speed mostly takes place after the

The next step of automation starts

extrusion process.

at the servo knife which has both verti-

He explains the process, is mainly too

cal and horizontal movements operated

quick for the eye to see. “To maintain

by servos with no pneumatics on either

production at 140 tiles per minute our

knife for absolute precision and accuracy.

equipment prepares the pallets with a

With closer tolerances the system eas-

micro-quantity of oil which is brushed

ily saves one percent of the concrete

on at just the right quantity for an even

used per tile through cutting off excess

spread.

material to make a perfect tile length,

The ABECE plants are a wonder to see

the excess material is returned to the

in operation. After batching and mixing

extruder to make tiles and reduce any

of concrete the pallet is rapidly moved

waste. Exact dimensions ensures no

PRECAST | ISSUE THREE | 2019

COVER STORY 3

G THE ROOF TILE INDUSTRY speed of production, the racking systems

cycle in a highly automated plant and the

the extruders and servo knives, to the

are efficient and carefully designed to

precision of manufacture, movement and

racking, curing, packing and conveyor sys-

gently handle tiles and reduce damage

handling means that there are hardly any

tems. Nowadays, operators and produc-

when curing.

quality defects and almost zero defects,”

tion controllers can get all the information

says Quintin.

that they need at a glance on screen or

The manufacturer’s innovation extends to curing with an approach that

even via a mobile device in certain instanc-

ensures less energy and effort is taken

Postproduction

es. The operations can then be modified

in the even curing of the tiles. By enclos-

Quintin explains that after curing, de-

and controlled as required, including line

ing the entire curing chamber, the right

pending on requirements for either top-

speed adjustments, power consumption,

environment is created for curing with

coat or through colour tile, it may need

plant parameters and alarms.

no heat losses due to constantly opening

further processing. Here it will either

doors during the loading period.

go to a rotary dryer for top-coated tiles

control stations including:

or straight to packing wherever colour

1. Extruder, knife and conveyor system.

through tiles are manufactured.

2. Racking and Hotbox curing chamber

“The ABECE plants make use of a Hotbox approach that encloses the

Post extrusion, the HMI’s typically

entire plant and uses the heat of hydra-

Robotic packing systems work faster

with capabilities to show quantity of rack

tion to cure the concrete more energy

and more precisely with no scratch

and tiles in the chamber and even col

efficiently. After curing the roof tiles

marks or chipping and less damages.

our of tiles in certain racks if specified.

are de-racked and separated from the

The robots are also able to maintain

3. Packing station (or backend) controls

aluminium or steel pallet. To minimise

production outputs around the clock for

including the rotary drier, loaders and

cement and additional energy for heat-

365 days per year. Depending on require-

up to six robotic packers, as well as

ing, this entire process of curing ideally

ments the ABECE plants offer a choice

the transport conveyors to the fork-

takes 24-hours for an efficient curing

of either a single loader with the ability

lifts in the yard.

“The ABECE plants make use of a hotbox approach that encloses the entire plant.”

to load tiles into packs of 10 at up to

HMI systems also allows pinpoint iden-

70 tiles per minute, or a twin loader for

tification of faults and allows users to find

up to 140 tiles per minute. In instances

root causes of faults down to individual

where clients require smaller packages

sensors. In addition, it provides a visual

for easier onsite handling, the robots can

picture of each section of the produc-

also split tiles into packs of 5.

tion line with visual representations of

Apart from higher speed and flexibility,

Fortunately for owners of existing

products and package them accordingly

plants, each and every section can be

when packaging them onto wooden

addressed separately and can be added

transport pallets.

to existing plants as required.

Human Man Interface (HMI) Through HMI’s all the features of the plant are available through the touch of a button. HMI’s provide a quick interface with the machinery and control everything from

PRECAST | ISSUE THREE | 2019

each process.

the robots are also able to identif y

(Top, from left): Up to six robots can work together in packing; robot small pack; twin loader and robot packing onto wooden transport pallets.

(Left): M32 extruder and double knife.

(Far left, from top): HMI overview and interface with the plant; HMI view of Hotbox curing room.

INDUSTRY NEWS

SA CEMENT PRODUCERS APPLY FOR PROTECTION AGAINST IMPORTS On behalf of the South African cement producers, The Concrete Institute (TCI)

5

has applied to the International Trade Administration Commission (ITAC) of SA to investigate the surge of imports of low-priced cement.

TCI has lodged the application on behalf of AfriSam, Dangote Cement SA, Lafarge Industries SA, Natal Portland Cement Company and PPC. Bryan Perrie, TCI MD, says imported cement is undercutting the industry by at least 45%. When this is combined with unprecedented low levels of demand due to slowed economic growth, the industry is faced with a survival crisis

In addition to the surge in low-priced

which thr eatens to undermine the

imports, a “carbon tax” was introduced in

industrial capacity of the country. “The

June 2019 on the South African cement

• Total imports increased by 139%

cement industry has no option but to

industry’s activities that has increased

request the ITAC to conduct a safeguard

the industry’s production cost. The effect

• Employment in the industry increased

investigation to determine whether the

of this tax translates to a 2% increase

• Imports have exceeded exports by over 50 000 tons during the past year. since 2016. by less than 0,5%.

cement industry requires

in selling prices, putting

• SA represents roughly 1% of total

protection from the surge

the local cement industry

exports from Vietnam, for example,

in imports,” he says.

at a further disadvantage

where exports have increased by 50%

against imports.

in the first half of 2018 to 15 million

tons, according to information pro-

vided by Global Cement.

Net importer Perrie says SA has become

High quality

a net importer of cement

Local pricing reflects the

Perrie believes the South African

with total imports increas-

standards (technical, so-

economy is at a crossroads where trade

ing by 139% since 2016,

cial and environmental)

policy determinations will play a critical

which makes trade remedy

that have been determined

role in determining the industrial direc-

protection vital to ensure

by SA as necessary for lo-

tion of the country. “The key to future

the viability of the cement

cal manufacturing. South

growth lies in achieving greater efficien-

industry. “Local produc-

African cement manufac-

cies within the country’s relevant manu-

ers have the capacity to

turing processes are regu-

facturing sectors. The cement industry

meet the Southern African

lated, from environmental

must compete on a level playing field and

Customs Union’s industrial demand and

impact assessments to strict quality

not be scrambling to survive against

must protect employment, broad-based

controls and from labour and employment

low-priced imports. The sector needs

black economic empowerment [B-BEEE]

regulations to sustainability require-

space to grow, which a successful ITAC

investments and environmental social

ments, and the country is a signatory of

application would provide,” he says.

and governance [ESG] requirements. The

the Paris Accord on CO2 emissions.

In support of the application, TCI has

South African cement industry needs to compete on a level playing field and not

outlined that:

against a surge of low-priced imports,”

• A total of 350 441 tons of cement

he declares.

arrived in SA during the second

“The South African cement industry is

quarter of 2019 – the most since the

very competitive. The cement, concrete

third quarter of 2015.

and affiliated industries employ thousands

• Most of the cement landed at Durban.

of South Africans whose jobs would be

The 260 909 tons that arrived there

on the line if local cement production

are an 85% increase on the first

weren’t protected. Importantly, several

quarter of this year.

pr oducers have signif icant B-BBEE

• Im p o r t s f r o m V i e t n am t o t a l l e d

investments which are at stake.”

PRECAST | ISSUE THREE | 2019

301 872 tons.

“The cement, concrete and affiliated industries employ thousands of South Africans.”

(Above left): The South African cement industry must compete on a level playing field and not be scrambling to survive against low-priced imports, urges Bryan Perrie, MD of TCI.

INDUSTRY NEWS

This article is meant as a challenge to housing authorities, developers and architects to revisit the past successes of concrete block modular masonry with a view to the positive impact its reintroduction would make in alleviating the housing backlog.

6

Concrete block modular masonry is a long-standing, internationally proven system which can do much to alleviate SA’s housing shortage. It was first specified by the local authorities in the late 1970s and early ’80s in the Western Cape, where it is still being used with great success. However, genuine concrete block modular masonry is rarely practised in other parts of the country these days and its reintroduction will require a reappraisal on the par t of the authorities and construction industry.

When f ir st intr oduced to SA by C o l um b i a D C M i n 197 8, c o n c r e t e block modular masonry was based on European and American standards and was subsequentl y SA BS-appr oved.

The system is similar to Lego in that a complete range of complementary blocks, such as corners, half, quarter and lintel units are supplied, in addition

and material incurred through chopping

GENUINE CONCRETE BLOCK MODULAR MASONRY: BETTER QUALITY, LESS COST

straight blocks to size, productivity is

system for building 35 000 economic

can top 18 (approx 65m²) houses a day

greatly improved.

houses in Mitchell’s Plain. Two other

during favourable summer months and

Independent masonry consultant

construction companies participated in

12 units a day during the rainy season.

Günter Koch says there were some

the development of Mitchell’s Plain and

notable modular masonry successes

the houses were built efficiently and on

New focus

in the early days of large-scale housing

time. A major initiative in the Western

“As things stand currently in the other

delivery. The City of Cape Town, for

Cape involved the training of novices and

provinces, many housing authorities,

instance, issued Columbia DBL with a

retraining of bricklayers in modular block

architects and specifiers appear to

contract to supply the full modular block

construction and many of today’s highly

have lost sight of modular masonry’s

skilled and ef ficient sub-contractors

economic and quality advantages

were recipients of that training.

and therefore don’t specif y its full

to the standar d modular 400mm straight blocks.

Economical solution Properly executed, modular construction i s m o r e e c o n o m i c a l t h a n im p e r i a l masonry. By eliminating wasted time

Thousands of modular block houses

implementation, ie the incorporation of

have been built in Mitchell’s Plain and

complementary masonry units in their

other ar eas in the Western C ape.

designs and specifications. As a result,

Koch observes that the rate of housing

most concrete block manufacturers in

delivery using modular block construction

these provinces have abandoned the production of complementary modular

(Above): A first course of modular masonry using hollow masonry blocks measuring 390 x 190 x 140mm is carefully laid out on damp course sheeting.

(Left): A modular masonry house under construction at Kleinmond. Note the angled roof blocks.

masonry products and, instead, are only producing straight blocks,” says Koch.

“S h o u l d g e n u i n e m o d u l a r b l o c k construction enjoy a revival in the rest

PRECAST | ISSUE THREE | 2019

with precise block layouts.

after time, the advantages of repetition

there’s a pool of experienced modular

“The benefits of detailed building

block-layers and modular block building

plans are obvious. In the first instance,

“The modular approach is ideally suited

inspectors who could motivate and assist

wastage is minimised by reducing the

to major housing initiatives. The CMA has

in training SME builders to adhere to

need for odd-sized blocks, which is so

detailed modular construction plans on

the correct building procedures. What’s

prevalent in the non-modular approach.

file together with schedules and other

more, the acquisition of modular block

Furthermore, by following a disciplined

information and there are many large-

building skills would provide a spur to the

and identical building procedure time

scale examples of successful modular

establishment and empowerment of small self-help modular, construction-based business enterprises.

“Ultimately, national and local authorities should insist on the implementation of proper full-scale modular construction not only at the design and tender process stages, but during the building process

“The modular approach is ideally suited to major housing initiatives.”

and mass production come into play.

masonry in the Western Cape and other parts of the country. In addition, we have leaflets and other written material which provide for and aid the design and application of modular masonry. This is available both online and in hard-copy format,” says Cockcroft. “ T he r apid ur b anisa tion o f S A’s

through their own inspectors and with

population is placing huge demands on

the assistance of NHBRC inspectors.

housing delivery and the reintroduction

Productivity would increase, wastage

of full and proper modular block

would be eliminated and, most impor-

construction would greatly assist in this

tantly, the quality of the finished product

process. But it won’t happen without

would be vastly improved,” adds Koch.

the lead from local government officials and mass housing contractors with the

Correct way

necessary initiative, drive and discipline

Henry Cockcroft, general manager of the

required for a successful outcome.”

Concrete Manufacturers Association NBC (CMA ), says modular masonry hinges on the provision of and adherence to detailed building plans and schedules

WHETHER BUILDING A BOX OR A ROOM ... we have a concrete solution for you!

(Left): A modular masonry house under construction at Kleinmond. Note the L-shaped corner block.

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INDUSTRY NEWS

of the country, the good news is that

7

As CMA members are probably aware,

precast concrete information. It’s a

successful project deliverance using

the association has embarked on a digital

go-to precast portal.”

quality precast concrete.

marketing strategy consisting of new and

Cockcrof t adds that the CMA is

“Due to the ease of this kind of col-

fresh Facebook and LinkedIn content,

constantly looking for ways to pro-

laboration and its advantages, we view

together with exciting new pages that

mote precast concrete as a preferred

this as a massive benefit to anyone

were added to the CMA website.

building medium, but this is impossible

who’d like to participate in this exercise.

CMA general manager Henry Cockcroft

In brief: the wider we cast the net, the

says the social media strategy has been

more advantage it will hold for precast

enjoying frequent engagement, with the

producers, architects, engineers, QS,

new website pages also gaining a lot of

specifiers, contractors and clients alike.

traction regarding site visitors.

“We need your contribution to cre-

“Although we’ve attained satisfactory

ate a valuable resource for our industry

results over the past few months with

and ask you visit our pages. By doing so,

the implementation of the digital strat-

you’ll automatically receive notification

egy, there’s still a void. We’d therefore

of all information disseminated by the

like to invite you to join us in this journey

CMA,” says Cockcroft.

and become part of it,” he says.

See the links below:

“There’s a big need for the distribu-

• LinkedIn – https://www.linkedin.com/

tion of easily digestible precast concrete

company/cmasa/

information, good practice guidelines

without involvement from the busi-

• Facebook – https://www.facebook.com/

and industry-relevant news. The nature

ness sector, corporate and private

of this information being posted will

professionals. “If we have that involve-

• Precast-Need-To-Know – http://www.

benefit each follower of and contribu-

ment, benefits will be delivered to our

cma.or g.za / Home / Pr ecast-Need-

tor to our Facebook page and LinkedIn

members. More than that, we’ll be

To-Know

company page, not to mention our new

creating a valuable resource for built

Hit the Like and Follow buttons to

website pages, which were specially

environment professionals in terms of

become part of the journey on Facebook

designed to provide clean and concise

an information portal which secures

and LinkedIn.

cmanpc/

CMA HOSTS FIRST ECSA-ACCREDITED WORKSHOP The Concrete Manufacturers Association

“We’re planning similar types of work-

held its first Engineering Council of SA-

shops around the country and aim to

accredited course at Emperors Palace

address areas where precast concrete

in Kempton Park recently.

is either being incorrectly used, or where

T he Concrete Pipes, Manholes &

opportunities exist to promote precast

Culverts – Design and Installation Work-

concrete over other construction tech-

shop, presented by well-known industry

niques,” says Henry Cockcroft, GM of

specialist, Alaster Goynes, was held

the CMA.

in conjunction with producer members

PRECAST | ISSUE THREE | 2019

This type of course is used to:

and was aimed at role-players in the

• Sharpen skills.

development of stormwater and related

• Reaffirm current knowledge.

infrastructure, as well as contractors.

• Clear design and installation uncer-

For the first time, Continued Professional

Development (CPD) points were allocated

• Guarantee better service delivery and

to delegates who attended.

tainties with regard to the technology. project completion.

INDUSTRY NEWS

REACHING OUT ON SOCIAL MEDIA

9

INDUSTRY NEWS 10

STANDARDS, CERTIFICATION AND ACCREDITATION While most construction professionals

by the South African National Accredita-

understand that standards are essential

tion System [SANAS] to certify precast

quality-markers, not many could claim

concrete products. Precast concrete

absolute clarity on how they are estab-

can’t be accredited, as some tender

lished, applied and maintained.

documents imply they can.”

C M A’s g e n e r a l m a n a g e r, H e n r y Cockcroft, set about filling in the gaps and

Clarity sought

clearing up misconceptions on standards

Cockcroft explained the process of how

and their relationship to certification and

standards are established in SA. He

However, once the lengthy drafting and

accreditation during a presentation at the

also cleared up another misconception,

approval process is completed, stand-

Cape Concrete exhibition in September.

namely, in whose name a standard is held.

ards are submitted to the DTI for sign-off

Cockcroft took a break from manning the CMA stand to deliver his presentation to delegates comprised largely of construction professionals. He explained that standards are of no benefit unless they are certified. Likewise, certification cannot take place unless officially recognised standards which specif y materials, quantities, safety and testing procedures are in place.

“There’s a strong correlation between quality management systems and the consistent supply of high-quality product.”

by the relevant minister.”

There are currently 16 precast concrete product categories which carry a SANS specification and, like CMACS, the SABS is the other body accredited

by SANAS to certify precast concrete units complying to these specifications.

Details of SA’s precast concrete standards, as well as all CMACS permit-holders, can be viewed on the CMA website.

Certification required

Quality first

He observed that certification is often

Cockcroft also outlined the central role

confused with accreditation. Simply put,

played by quality management systems in

certification is product-related and, if

meeting national standards and certifica-

successful, verifies that a product has

tion requirements. He sketched the audit

met all the specifications of a national standard.

process producers must undergo before Some still believe that the SA Bureau of

gaining certification for their products.

“Some manufacturers sometimes

Standards (SABS) is the custodian of

“There’s a strong correlation between

state that their products are accred-

SA’s standards, whereas it is the De-

quality management systems and the

ited, which is a meaningless claim,” said

partment of Trade & Industry (DTI) which

consistent supply of high-quality prod-

Cockcroft. “Products can only be certi-

fulfils this role.

uct. Producers which adhere to qual-

“The SABS is simply a service pro-

ity management systems enjoy greater

“Accreditation is function-related,

vider. It plays a facilitating role in the

customer loyalty and are generally more

recognising that someone or an organi-

establishment of new standards and the

competitive and profitable,” he said.

sation is qualified to perform a certain

modification of existing standards and

function. For example, the CMA’s Certi-

participates in workgroups comprised

fication Services [CMACS] is accredited

of related producers and professionals.

fied, not accredited.

(Top, from left): Henry Cockcroft, general manager of the CMA, addresses delegates at Cape Concrete and the CMA stand at Cape Concrete.

PRECAST | ISSUE THREE | 2019

INDUSTRY NEWS

Several CMA producer members are using recycled (or, more appropriately, repurposed) aggregates to produce various concrete products – such as bricks and blocks at quality levels equal to the same products made with natural aggregates.

Notwithstanding repurposed aggre-

11

gates’ ecological benefits, their use is thus far neither recognised nor encouraged by local authorities such as carbon or mining credits. By contrast, in most of the developed world they are not only acknowledged, but mandatory.

“Official recognition of repurposed aggregates and the impor tant role they play in sustainable construction is long overdue,” says CMA general manager Henry Cockcroft. “This is why repurposed aggregates form part of a review being undertaken by SABS and the CMA on the SA National Standard for aggregates.”

Care required Sourcing natural aggregate from quarries is considered harmful to the environment in North America, while in Europe, up to 90% of aggregates must be sourced from repurposed aggregates. Even in SA, a complete environmental plan must be submitted and approved before a new quarry can be established.

RECYCLED CONCRETE DESERVES OFFICIAL RECOGNITION who use repurposed aggregates are

requirements for ABT qualification.

“Repurposed aggregate is prepared

more competitive, without any loss in

“B u i l d i n g p r o d u c t s w h i c h h a v e

in precisely the same way as natural

quality. This offers very positive socio-

acquired ABT status are sometimes

aggregate. It’s crushed, screened and

economic spin-of fs, especially in the

more expensive than conventional blocks

graded according to size and stockpiled.

entry-level housing market, where a

and bricks.

Moreover, it’s subject to exactly the same

greater number of houses can be built

quality standards as natural aggregate-

with repurposed bricks and blocks.

based products,” comments Cockcroft.

Natural aggregates must be mined using a variety of tools and equipment, and then processed. This approach can be very harmful to the environment, hence the implementation of certain mining and carbon taxes. By contrast, r epurposed aggr egates come f r om existing building material, allowing the conservation of natural resources and eliminating the need for dumping and

“ F o r e x a m p l e , a n A B T- c e r t i f i e d

aggregates earning carbon and mining

building block made with a lightweight

“What we’d like to see are repurposed aggregates earning carbon and mining credits.”

landfill space – a recognised problem in Cape Town and others metros.

Status required

“What we’d like to see are repurposed

material was recently used on a lowcost building pr oject in Cape Town at a price considerably higher than conventional building blocks. Moreover, it had to be transported all the way f r o m J o h a n n e sb u r g, a t a d d i t i o n a l substantial cost to the authorities and the environment. Had a repurposed block been specified on this project, more houses could have been built.

credits. In addition, we believe they

“We feel that repurposed aggregates

should also be recognised by metros

should qualify for ABT status because

Rising prices

as an alternative building technologies

they’re genuinely eco-friendly. There

“Over the past five years, the price of

[ ABT ] material. ABT is used by the

should also be a certification process for

natural stone aggregate has risen by up

authorities to promote, among other

their use and they should be specified in

to 25% and this is reflected in the price of

things, a more environmentally friendly

tender documents,” says Cockcroft.

natural aggregate-based end products.

and progressive way of building, although

However, precast concrete producers

ther e’s still uncer tainty about the

PRECAST | ISSUE THREE | 2019

(Above): Repurposed aggregate.

9 9 5 R d mende Recom ing VAT d lu c n i price

WORLD PREMIÈRE OF CON-TEXTURES SCULPTURE The world’s first large-format carbon concrete sculpture, CON-

TEXTURES, was unveiled in November last year at one of the most important European textile events, the Aachen-DresdenDenkendorf International Textile Conference (ADD-ITC). It consists of two textile concrete shells, each 2,4m high. With a wall thickness of 20mm, the sculpture is carbon-reinforced and was created in exclusive collaboration with Düsseldorf artist Thomas Schönauer.

The technical innovation of fibre-reinforced concrete expands the creative possibilities of the artist, allowing the creation of shapes which are not achievable with non-reinforced concrete.

Schönauer’s CON-TEXTURES sculpture project incorporates the latest carbon concrete research by Prof Dr Thomas Gries of the Institut für Textiltechnik of RWTH Aachen University (ITA).

Working with textile-reinforced concrete is one of the institute’s most important areas of research.

The ITA is an ideal partner for Schönauer, who is particularly interested in the filigree possibilities of textile concrete. He has also created other curved concrete sculptures up to heights of 5m and their filigree surfaces depict numerous images such as landscapes, waves and rain.

Art and science have always been regarded as opposing disciplines. The CON-TEXTURES project pursues the opposite strategy. Not for nothing do great scientists and philosophers talk about the unity of beauty, truth and goodness.

CON-TEXTURES appeals to anyone with an affinity for art. The sculpture is offered in three different sizes and is being marketed

by Düsseldorf gallery Engelage & Lieder. At over 5m high, the largest sculpture has been placed in a public space. Partners are still being sought. Contact Andreas.Koch@ita.rwth-aachen. de if you are interested.

(Above): Prof Dr Thomas Gries (left) and ITA artist Thomas Schönauer at the unveiling of the CON-TEXTURES sculpture at the ADD-ITC.

PRECAST | ISSUE THREE | 2019

PRODUCTS 14

NEW ADMIXTURE PROVIDES LASTING SEWER PROTECTION Concrete additive supplier, Xypex Chemi-

troublesome alternative materials such

components are fixed in a mineral matrix

cal Corporation, has introduced an

as composites, plastics or steel.

within the concrete and will remain ac-

infrastructure-sparing admixture that

“Concrete containing Xypex Bio-San

tive, working indefinitely to kill harmful

provides antimicrobial and waterproof-

C500 maintains all of its original proper-

microbes at a cellular level. It does this

ing properties for concrete products in

ties, including workability, while providing

through the constant release of metallic

sewer environments.

an impermeable surface that remains

ions which open holes in the bacteria’s

MIC-resistant for the duration of the

cell membranes, thus destroying them

lifespan of the concrete,” says Minney.

from the inside.

In certain situations, acid-producing micro-organisms – including the Thiobacillus group of bacteria – are able to eat

Due to its structure, it is an integral

away sewers through microbial-induced

part of the concrete and therefore can

corrosion (MIC), which produces biogenic

never be washed off or wear out. It will

sulphuric acid that reduces the surface

continue working indefinitely for as long

pH of the concrete and leads to rapid de-

as the concrete is in place. This is in line

cay of the infrastructure. The breakdown

with new mandates of infrastructure

of wastewater infrastructure allows leaks

owners who are seeking longer-lasting

to develop, which can ultimately affect the

alternatives to current methods.

integrity of the pipelines and cause the complete collapse of the system.

World leader

While alternatives do exist, including

“Our product is being used widely in

PVC pipes, crystalline waterproofing

markets throughout the world, wherever

and chemical-resistant coatings, these

longevity of infrastructure is required.

have limitations and are not always ideal

It’s a comparati vely cost-ef f ecti ve

for every type of application, especially

means of protecting infrastructure and

large-scale and larger-diameter pipe

provides engineers with real-world solu-

applications. In these circumstances,

tions to extend the lifespan of wastewa-

the simple addition of the powder form

ter infrastructure,” says Minney.

“In the past, engineers may have de-

Xypex Bio-San C500 admixture provides (Above, from top): Crystalline growth begins in concrete; crystalline growth completely fills openings.

signed special mixes to try to stave off

Simple procedure

have turned to alternative materials that

Concrete advantages

He explains that the dual-protection

aren’t as effective as concrete and, in

According to Xypex (UK) LLP export

product is manufactured in the form

most instances, are far costlier.

sales manager Stephen Minney, the

of a dry powder that can be added to

“With the addition of our Xypex Bio-San

new admixture is an exciting innovation

concrete manually or through computer-

C500 in precast products, infrastructure

for precasters who can easily extend

controlled batching systems. It can also

can simply be lifted into place and even

their product range and compete in new

be added directly to the central mixer in a

added to grouting to provide true install-

markets. Xypex Bio-San C500 concrete

plant and provides precasters and ready-

and-forget projects for our wastewater

products will have built-in, long-term

mix producers with a product that can

utilities. It also provides exciting new

protection for harsh sewage conditions

be added to their product line-up or for

prospects for our precast community,

where MIC attacks are likely. The additive

special projects, wherever it is required.

who will be better able to compete against

combines potent antimicrobial protection

Upon final curing, the antimicrobial

permanent protection for precast and in-situ concrete structures.

damage for as long as possible, or may

alternative products in future.”

along with the unique crystalline technology of the Xypex Admix C-Series.

“It prevents MIC, stops infiltration/ exfiltration of water and provides acidand sulphate-resistance, significantly extending the service life of concrete sewage collection systems and wastewater infrastructure. This, in turn, provides design engineers with the option of using these to extend the life of the infrastructure projects and enjoy the benefits of strong, durable and cost-effective concrete, rather than costly and potentially

PRECAST | ISSUE THREE | 2019

PRODUCTS 15

EXTRAORDINARY PRECAST PRODUCTS Climate change has brought about major

portation points, thereby increasing

changes in weather cycles. The need for

commuter safety and convenience. Rocla

commuters to find shelter from dramatic

also offers concrete taxi rank shelters

rainstorms and the parched heat of

and bus stops, as well as other related

summer has increased the requirement

street furniture such as concrete ven-

The “sloping-back” profile enables road-

for solid, safe and indestructible bus

dor stalls, sanitation units and concrete

rollers to operate right up to the edge

shelters for those using municipal and

street lighting poles. Contractors are

of the pavement without scratching

local transportation.

easily able to transfer the bus shelter

or damaging the kerb face when the

CMA member and ISG Group com-

installation skills to members of local

surfacing is laid.

pany Rocla has developed a virtually

communities, which can form part of

On slower rural roads, the kerb can

indestructible and vandal-proof precast

their community outreach programmes.

provide an element of safety through

concrete bus shelter which offers shel-

impact redirection. On fast-moving

ter from heat and rain, as well as seating

Kerb stones

freeways and highways, the kerb is

in its modular design. The durability of the

When bad weather does occur, it is

more often used for drainage. It is also

concrete product guarantees decades

important to channel the water away

frequently applied near bridges, where

of maintenance-free life, an important

from the road surface with properly

erosion is a possible factor and to

feature for cash-strapped local munici-

developed kerbs and gutter systems.

establish a clear and visible separation

palities wanting to ensure budgets for

The widespread construction of kerbs

of people and motor vehicle lanes.

street furniture are well spent. It also

only began in the 18th century, despite

prevents structural vandalism.

them having been around since the days

Perfect combinations

of Pompeii!

A combination of a Technicrete barrier

The Rocla bus shelter can be supplied with wind walls for one or both sides of

Originally utilised for the beautification

kerb and a C900 gutter section will

the shelter and although supplied in a light

of the city and to separate transportation

convey drain water to the nearest kerb

grey colour, the surface is easily painted

from pedestrians, the humble kerb has

inlet. Road resurfacing requirements will

for advertising, roadside markings and

evolved into an infrastructural necessity

not need realignment with the kerb line

community notice purposes.

– f or example, it pr e vents dr i ver s

either. The Technicrete semi-mountable

Of fering commuters shelter from

from parking on pavements and lawns,

kerb can also be utilised in conjunction

inclement weather, the Rocla solid bus

while providing structural support for

with the C900 gutter section for drainage

shelter can also lead to the creation

pavement edges.

purposes on roadways and elsewhere.

of centrally situated community trans-

“Contractors are easily able to transfer the bus shelter installation skills to members of local communities.”

PRECAST | ISSUE THREE | 2019

Another CMA member and ISG Group

The company’s barrier kerbs have

company, Technicrete’s precast barrier

been specified for projects such as

kerbs have been successfully installed

medical centres, national roadways,

on numerous regional infrastructural

pri vate and commer cial r esidential

projects throughout SA due to their

developments, gutter systems and rural

100% local manufacture and excellent

infrastructure upgrading.

quality. The kerb uses the “half-battered” profile. This more vertical face offers a type of barrier to alert motorists that they are dangerously close to the edge.

(Top): Kerbs play an important role in traffic management.

(Above): A bus shelter in Gaborone Road, Francistown, Botswana.

COMPANY NEWS 16 The country’s only equipment manufacturer specialising in concrete roof tile plants, Jessop & Associates, is celebrating 30 years of service to the roofing industry.

Since launching its original Protile Double Roman tile profile in 1986, the company has gone on to develop a wide range of machines that have become a mainstay of operators across SA and around the globe. After the initial success of the early machines, new developments included the well-known Protile Tuscan, which was among the first to gain wide-

LOCAL MANUFACTURER LEADS THE WAY IN ROOFTILE INDUSTRY

spread local and global success, followed

in 1978. After completing four major

by the Protile Shingle.

tile plant projects with that company,

(Left, from top): The Protile P70HD, capable of extruding 100 tiles per minute and a typical materials handling layout, with bins and conveyors feeding sand and cement automatically into the mixer.

According to Jessop & Associates

I decided to launch Jessop & Associ-

founder, Grahame Jessop, the company

ates and have never looked back. Now,

is the only equipment manufacturer

with 125 tile plant projects in over 30

“The extensive seminar manual and

in Af rica capable of manuf acturing

countries, the Protile equipment brand

notes have since become something of

a n d i n s t a l l i n g sp e c i a l i s e d t u r n k e y

is synonymous with quality in many parts

an industry ‘reference book’, in many

plant and equipment for high-speed

of the world.

instances, while internally, the next

continuous extrusion of concrete roof

“Passing on this vast experience has

generation has also taken up the cudg-

tiles, at speeds of over 100 tiles per

become an ongoing journey for me and

els. My son, Ronald, has also been using

minute. “In fact, there are probably only

led me to develop and present a range

his professional engineering expertise in

three companies worldwide with this

of workshops and seminars specially to

product development for over a decade

capability, with the other companies

develop the skills of plant for local and

now,” says Jessop.

only having local agents who import such

international markets in South America

equipment,” says Jessop.

and Australia. These have been met with

Material anomalies

great success and it’s not uncommon

He adds that in addition to a sound

Right timing

for our South African seminars to be

knowledge of the operation of plant and

“I started my career in the concrete roof

attended by concrete roof tile manufac-

equipment, it is vital to have a good

tile industry with a UK-based company

turers from foreign countries.

understanding of the specific characteristics of raw materials for the extrusion process in this industry. For this reason, one full day of the three-day seminar is dedicated to exploring and demonstrating these criteria. During this time, it is shown that the aggregate gradings alone are of relatively little value.

The mineralogy is crucial, as are particle shape and texture, interstitial moisture and water requirements of the aggregates. This information, together

(Left): Grahame Jessop, MD of Jessop & Associates.

(Above): Ronald Jessop, director of Jessop & Associates.

with a WET grading analysis resulting in a more relevant FM calculation, minus 75-micron content and characteristics

PRECAST | ISSUE THREE | 2019

COMPANY NEWS

and flow properties tested using a flow cone apparatus, enable an optimal mix blend design for extrusion to be achieved.

The concrete roof tile industry is very demanding, requiring the expert assimilation of this data to gain a competitive edge in a market where the variation between an aggregate/cement ratio of

17

3.85:1 and 3.95:1 could make a significant difference to margins.

Forming tiles

(Above): The Protile Double Roman Tile, well established in SA since the 1980s.

(Right): Aluminium alloy pallet cast under high pressure.

Jessop explains that given the critical mix design parameters, the high-speed

cal. This becomes more apparent at higher

“The risk is high, as is the capital ex-

extrusion process requires precise

extrusion speeds. These high-production

penditure involved. Due to the extreme

control of concrete flow in the extrusion

tile plants need to strike a fine balance be-

extrusion forces, optimal strength-to-

head. The new Protile Double Roman Mk

tween tile body thickness, typically within

mass ratio is crucial for the pallet. Only

VI aluminium pallet, for example, is a far

a tolerance of 11mm ± 0,25mm, and tile

aluminium achieves this, with no flexing

cry from the Mk II Double Roman pallet

depalleting strength, which could be as

of the pallet, in a cost-effective manner,

of the 1980s.

low as 900 Newton at 24 hours testing.

borne out by the fact that after exten-

Since the bottom surface of the

sive research, 95% of the industry uses

concrete roof tile is completely formed

Aluminium pallets

via the detailed design of the aluminium

“Jessop & Associates budgets approxi-

“Should flexing occur – as it does

pallet, a lot of the success in terms of

mately 12 months for the development of

with steel pallets – then the tiles formed

“compaction” or extrusion density lies in

a new or current aluminium pallet design,

won’t conform to stringent roofing

the pallet design.

followed by a further six months for manu-

criteria. They’ll ‘rock’ and have varying

facturing the high-pressure die needed to

overlapping and interlocking gaps. The

cast these pallets,” says Jessop..

less-known advantage of the aluminium

The material flow enabled by the design of the aluminium pallet is, of course, criti-

aluminium pallets worldwide.

COMPANY NEWS 18

is the formation of aluminium stearates during the extreme extrusion pressure to form a physical interface barrier between concrete and pallet, thereby assisting high-speed depalleting of tiles from pallet.

Plant projects “Typically, a high-speed tile project will take us 12 months from project confirmation by the client to commissioning of the new concrete roof tile plant.

In this time-frame, the detailed plant configuration is finalised, considering any restraints imposed by existing building and other limitations, followed by mechanical plant detailing, followed

(Above): Sophisticated tile curing systems are an integral part of Protile concrete roof tile plant projects.

by manufacturing of the Protile plant

high-energy Eirich mixer and the double-

which were the severe limitations imposed

and equipment. A plant can easily involve

deck vibrating screen, all the equipment

by the available land and buildings.

manufacturing more than 35 individual

is manufactured in the Protile workshop

Tile plants of this nature to produce

Protile items of equipment.

in the Vaal Triangle, pre-assembled and

30 000-40 000 tiles per shift would

then installed on site,” says Jessop.

typically cost R25 million-R50 million,

“There are three distinct project

depending on many variables, such as

sections to be considered – the tile plant circuit (including the extruder), the mate-

Recent projects

the level of automation for the curing

rial handling system (which includes sand

Complete Protile P70HD tile plant projects

chambers and dry tile handling.

screening, weigh batching and mixing)

were recently commissioned for well-

With these and other projects on the

and the tile curing system, including the

structured and managed black empower-

horizon, Jessop & Associates looks set

curing chambers.

ment entities in Gauteng and Limpopo. The

to face the next 30 years of manufactur-

projects had their challenges, not least of

ing excellence.

“With the exception of the specialised

Find our branches at www.technicrete.co.za

p a v in g | mini ng | m as onr y

SUITABLE FOR: • Car parks • Industrial Estates • Retail Centres • Pedestrian areas • Domestic Drives • Motorways | Garages • Service areas

| k erb s | erosi on

protec

APPLICATIONS: • Tongue & groove • Standard grey or traffic calming colours • Precast • Various sizes available • Highest quality

tio n | r et a i

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Technicrete is a subsidiary of ISG, a leading supplier of innovative infrastructure products to the construction and mining markets in Southern Africa.

MARKETING PRECAST PRODUCTS

By Andrew Meyer, andrewisikhova@icloud.com “The times they are

I could sell existing product?” For

a-changing,” sang

example, slabs are now also used

B o b D y l an – an d

for walling. Previously – barring paving

in an ever faster-

and retaining walls – most precast

changing world, we

product was viewed as structural

need to look at how

a n d n o t a e s t h e t i c . T im e s h a v e

we see our product

changed and concrete has become

application. What

fashionable, opening many new doors.

will be needed in

O v e r t h e p a s t f e w y e a r s, n e w

the future and how will we market to our

consumers have begun making new

users? It is said that while we used to

demands and viewing precast concrete

see a generation as 15-20 years, it has

in a very different light. The Museum

now changed to four years.

of Modern Art in Paris, for example,

A product and marketing plan is an

has installed all pipes and conduits on

extremely intensive plan and differs from

the outside, rather than in the walls.

company to company. Developing this

By applying colour to them, this has

involves some crucial steps:

become art in itself. A well-known precast

1. Evaluating your current product

concrete manufacturer in Johannesburg

offering. This needs to be done by

launched a security wall system a few

firstly looking at your sales patterns

years ago. This is a stunning structure

over the past three to four years.

and could easily be used in parking lots

Have sales declined, remained the

or parks, possibly with a bench and light.

same or grown? If they’ve grown,

The precast concrete pipe sector is

then “don’t fix what isn’t broken”.

currently going through difficult times

What product development and re-

and some major players have had to close

search have you done to look at

down. In today’s media, you are always

the needs of your customer s in

confronted by “green issues”. Why does

today’s world?

the pipe sector not use all this free

2. Marketing patterns have changed,

publicity to position precast concrete

and marketing and sales structures

as far more environmentally friendly than

are very different today from what

plastic pipes? Push the issue of more

th e y w er e 10 y e ar s ag o . W hil e

and more plastic being put into our soil

marketing in dedicated trade journals

that isn’t biodegradable. A better option

remains a very effective method of

for pipes is precast concrete, which is

getting the message across, general

biodegradable!

print media, radio and TV penetration

Concrete blocks have mainly been sold

has dramatically shifted. Are you

based on a cost issue, and this has had

using social media and dir ect-

a negative impact on the use of blocks,

response methods to reach your

which are seen by some as the “cheap”

clients? Have you evaluated who

or “second-rate” option. We would be

your potential client base are today,

far better off selling a “quality” product

as opposed to who they were in the

that is sustainable and has good thermo

past and are you reaching them in

qualities, as well as sound insulation.

an effective manner? We live in an era

What is more, concrete comes at a

of branding – how much of this are

better cost per running metre.

you doing?

In summary, I believe we need to

3. Different assuages for precast mat-

look at our product, the applications,

erial: look at the product you manu-

possible new markets and how we sell

facture and ask yourself: “Is there

and market our product in the most

possibly a different market to which

effective way.

PRECAST | ISSUE THREE | 2019

COMPANY NEWS 20

REVELSTONE GEARED FOR GROWTH

the built environment, and we felt that

and inlays in an enticing display. Over

if we couldn’t renew our own space, how

time, it will demonstrate how well our

could we invite others to do so?”

wet-cast cobbles and pavers wear,”

Cape-based cast-stone producer and

and off-shutter concrete with steel clad-

New products

CMA member, Revelstone, believes that

ding and new lighting for an attractive

“A key element in the upgrade was an at-

a bright future beckons the South African

nightfall frontage.

tractive new front entrance which allows

Revelstone’s new façade was modern-

says Cyprianos.

ised by combining Random Stone cladding

cast-stone manufacturing industry.

easier access to our new showroom and

Underscoring its commitment to an

incorporates a modernised step, as well

expanding market, the company launched

as a ramp for wheelchairs and sample

several new products during a PPC-

trolleys,” he explains.

sponsored open day on 2 August. It has

Revelstone’s new product line-up

also invested liberally, adding to its re-

includes three newly-designed granite fin-

cent showroom upgrade with a redesign

ished cobbles (Exeter, Trent and Tuscan),

and makeover of the exterior road-facing

a new flagstone paver (Devon Straight

façade of its HQ premises, Adam House.

Edge) in two sizes, new stone cladding

Moreover, the company is committed to

(Cotswold) and a new kerb/step (Oxford).

upgrading its plant and equipment during

“As always, our new product range

the coming year.

is based on input from the architectural

Founder and chairman Andrew Cypri-

community, consumer demand and mod-

anos says Revelstone was built on op-

ern trends in landscaping design,” says

timism and faith in positive outcomes.

Cyprianos.

Opportunity abounds

producing customised cast-stone prod-

“Everyone warned me when I established

ucts since 1993 for both the domestic

the business 26 years ago that I was

and commercial markets. The company

making the wrong move. The prevailing

uses traditional masonry skills combined

economic and political mood at that time

with modern moulding techniques to

was one of ‘wait and see’, ahead of the

painstakingly produce master moulds

1994 elections, and the business com-

from original stone. This hands-on ap-

munity was holding back on investing in

proach allows the creation of custom-

new ventures. We’re in a similar position

made products, tailored to clients’

today. While others tighten their belts,

specific requirements.

Family-owned Revelstone has been

we believe the current downturn provides the ideal opportunity for renewal and regeneration,” says Cyprianos.

“In addition, we redesigned our road

“We could easily have continued with

verge and parking area, which was relaid

our old showroom and building façade

by Progressive Paving. It showcases

and banked the money. But we’re in the

our full cobble, edging, kerbing, drainage

business of beautifying and remodelling

pavers, demarcation pavers, borders

(Top): Revelstone HQ, Adam House, sports a new façade and paved road verge.

(Left, from top): Revelstone chairman Andrew Cyprianos (right), seen here with business consultant Chris Rookledge (left) and Clayton Laue of Paarman Landscapes during the launch of the company’s new product range in August; Tuscan Cobble in three sizes and Cotswold cladding.

PRECAST | ISSUE THREE | 2019

COMPANY NEWS

(Right, from top): Sanitation units donated by Rocla to Sifunindlela Primary School and members of the Mpumulanga Department of Education; Rocla (ISG) CEO Albert Weber shakes the hand of the Sifunindlela Primary School principal; André Labuschagne, product development manager: Rocla; Malebusa Sebatane, marketing & communications manager: Rocla (ISG).

“No school should be without proper functioning and clean sanitation units.

21

It’s called human dignity,” said Albert Weber, chief executive officer of the Infrastructure Specialist Group (ISG) when he recently handed over 16 Rocla precast concrete sanitation units to the Sifunindlela Primary School, based at Kabokweni in Mpumalanga.

“At ISG, our corporate social initiative focuses on early learning development projects. At Sifunindlela Primary School, we saw a need for hygienic and safe sanitation units for its very young pupils and we knew we could assist through the expertise that CMA member Rocla has in this sector. Our belief that functional ablution facilities should be provided for young pupils attending educational establishments stems from our belief in the right to basic human dignity. We at ISG and Rocla are proud to have supplied these 16 dignified and safe sanitation units,” Weber said.

“We contracted Enviromould Product Solutions for the installation of the toilets. They supplied amenities for upstream water and downstream sewer management. The finished product comprised two sets of toilets for both girls and boys. The seats supplied include a built-in baby-seat to accommodate both pre-schoolers and much older children in primary school. These sanitation units are safe, hygienic and fully functional

PRECAST SANITATION UNITS FOR MPUMALANGA PRIMARY SCHOOL

and replace previously dangerous pit

installation and backfilling of the septic

running water is available, plastic fittings

toilet installations,” commented André

tank and the installation of a 5 000-litre

are used to prevent theft, as these have

L abuschagne, product development

water tank on a raised platform to

no scrap value.

manager at Rocla. “The sanitation unit

gravitationally feed the toilet cisterns.

In the case of leach pit latrines,

itself is cost-efficient. There’s no need

Rocla’s precast concrete toilet unit

the leach pits themselves are also

for any educational establishment not to

is a cost-efficient solution to one of the

manufactured from concrete and

have units such as these installed for its

essential needs in SA’s high-density

supplied together with the toilet unit.

pupils and staff.”

urban and rural communities. The stand-

This provides a system in line with the

Enviromould supplied all associated

alone unit has been developed to be used

Water Research Commission’s findings

sanitation unit fittings such as stop

as either a leach pit configuration or as

for a cost-effective and viable on-site

c o c k s, w a t e r c o nn e c ti o n f i t tings,

a fully water-borne system. The unit is

water-borne system.

infiltrator soak-away chambers, sewer

supplied complete with a high-quality

Sifunindlela Primary is a no-fee public

pipes, water troughs and vent valves,

polymer pivot door and an optional

school and has over 1 100 registered

as well as conducting the excavation,

concrete add-on wash basin. Where

pupils, with over 100 in Grade R.

“Rocla’s precast concrete toilet unit is a cost-efficient solution to one of the essential needs in SA’s high-density urban and rural communities.”

PRECAST | ISSUE THREE | 2019

GLOBAL VIEW

US PICP CONFERENCE ADVICE:

DON’T INSTALL IF YOU CAN’T MAINTAIN An entire session was devoted to per-

22

meable interlocking concrete pavement (PICP), which was attended by Prof Neil Armitage, deputy director: Future Water at the University of Cape Town. Regular

Precast readers will recall that Armitage is spearheading research into the

America’s Environmental & Water Resources Institute staged an Operation & Maintenance of Stormwater Control Measures conference from 4-7 August in Minneapolis.

performance of local PICP installations.

The American stormwater conference forms part of his monitoring developments internationally and exploration of how they can contribute to sustainable PICP installations in SA. Two factors critical to the future of PICP emerged during the conference. The first is that the American Society of Civil Engineers has announced the launch of

(Above): Prof Neil Armitage, deputy director: Future Water at the University of Cape Town.

a PICP standard which sets the stage for similar initiatives in other parts of the world. The second is that the USA’s

and maintenance guidelines. A detailed

The routine maintenance machines

Interlocking Pavement Institute (ICPI),

guide f or civil and envir onmental

combine blowing with vacuuming, whereas

which champions the use of precast con-

engineers, it provides informative reading

restorative maintenance requires a

crete segmental paving, now advises that

for environmental planners, landscape

sweeper to remove stuck sediment and

unless property-owners are prepared to

architects and architects. Armitage

stones from the cavities between pavers.

maintain their PICP installations, they are

believes that a similar standard would be

The restorative system which gave the

wasting money by installing them.

of benefit locally and part of his research

best results was the Typhoon. Powered by

is geared towards achieving that goal.

a large street vacuum truck, it comprises

One of the speakers during the PICP

two small, wheel-mounted machines, one

Four years in the making, America’s PICP

session was David Smith, the director of

for blowing and one for sucking up debris.

standard, ASCE/ANSI 68-18, covers

ICPI, who has visited SA and is well known

The Typhoon can clean approximately

hydrologic sizing and the structural

to some CMA members and concrete

100m² per hour and Armitage believes

design of PICP, as well as construction

block paving manufacturers. The author of

that one set could probably service all

a book on PICP, Smith presented a paper

PICP installations in the Western Cape.

entitled Best Practice in Maintenance.

Other machines tested included the Ditch

Compiling guidelines

His presentation focused on main-

Witch, a small vacuum machine for small

tenance and the various types of PIPC

installations and the Billy Goat, which is

cleaning equipment currently available on

used for cleaning sidewalks.

the American market, never losing sight of his overriding message that ongoing

Interesting observation

maintenance is essential to the viability

Armitage noted that, unlike the British,

of PICP installations.

Americans tend not to install geofabric under the bedding layer. “This may be due

Maintenance required

to the fact that although one gets the

The ICPI recently tested several PICP

best nutrient and toxin removal with an

cleaning machines and Smith gave some

upper layer of geofabric, clogging occurs

insights into their use and performance.

a lot quicker,” he explained.

He ad v ises tha t in the US A, PICP

A r e c en tl y c omple t e d f our -y e ar

maintenance essentially falls into two

comparative study in the USA between

categories: routine maintenance (which

permeable concrete, permeable asphalt

is designed to delay the onset of clogging)

and PICP has shown that although PICP

and restorative maintenance (which

clogs quickly, it is much easier to clean

is used to unclog clogged or partially

than asphalt or concrete. It is also much

clogged installations).

easier to work with over the long term.

PRECAST | ISSUE THREE | 2019

TECHNICAL

Most precast concrete manufacturers k n o w M ap e i f o r i t s v a s t r ang e o f construction chemicals, admixtures and adhesives, yet few realise that its influence begins far earlier in the construction cycle, with the provision of advanced chemicals that aid cement manufacturers in the production of high-

23

quality cement.

In SA and worldwide, Mapei is a major supplier of cement additives and grinding aids that improve the characteristics of cement, thereby enabling producers to increase throughput and so achieve better efficiencies and lower costs per ton of cement sold.

Laurence Gopane, Mapei product manager for cement additives, says

QUALITY FROM THE BEGINNING

cement is produced with a complex recipe

starts with lab testing of the specific

of clinker and other ingredients including

raw material.

gypsum, fly ash, slag and limestone,

T his usually r esults in an initial

among others. Every additive is tailor-

prototype of grinding aids, which is then

made for each and every plant to support

tested in the mill and adjusted according

the particular ingredients, as well as the

to the actual outputs and requirements.

manufacturing processes.

In the end, however, the result is the best possible product that can be produced cost-efficiently from each manufacturing

Careful selection

plant. And, for the end user, it results

“Regardless of the mix, even plants within the same organisation may have

facturers rely on these additives to

in the best-quality cement at the best

different recipes with their own unique

achieve their production goals. Needless

possible price per bag or ton.

challenges. That’s where our team comes

to say, since Mapei’s entry into the local

“For contractors and other users,

into its own. We’re able to partner with

market some 10 years ago, the game has

the use of quality cement is critical in

the producer and recommend products

changed and our modern additives have

producing high-quality concrete for local

that will assist in meeting the specific

offered many advantages that ultimately

building sites. It also enables cement

requirements,” adds Gopane.

improve the quality of cement to end us-

producers to keep up with the high

ers,” says Gopane.

demand for quality cement in either bulk

“For example, some additives are

or bags. This is when our team from

grinding aids that improve the grinding action of the mills by preventing particle

Live tests

Concrete Admixtures will be able to add

agglomeration and adhesion to equipment,

He explains that due to the technical

further technical support and benefits,”

and there are different types available that

complexity of the cement manufacturing

says Gopane.

improve the strength of performance.

pr ocess, ther e ar e many dif f er ent

Mapei grinding aids and performance

variables that need to be considered

Giving back

enhancers influence the properties of the

when adding additives. These include the

Mapei also hosts an annual Cement

final cement. Producers are therefore

type of clinker being used, mix ratios of

Additives Seminar which is open to all

able to ‘tweak’ cement to have different

slag, fly ash and other ingredients, as well

cement producers and blenders, whether

properties, such as optimising early

as equipment type, grinding media and a

or not they are current customers.

strengths and late strength gains, etc.

host of other variables.

Specialists and technical consultants

“The country’s large cement manu-

The selection of the cement additive

from the company’s C-ADD division in Milan, Italy, come to SA to interact, educate and present relevant content to the attendees about the cement additives industry.

The event sheds light on the latest best practices, technologies and products available to help cement producers keep up with new and challenging demands.

The next 2020 Cement Additives Seminar is anticipated to take place during the second quarter of 2020.

PRECAST | ISSUE THREE | 2019

TECHNICAL

As with many other materials, there are potential risks involved in handling or working with Portland cement or mixes made using it. Here Bryan Perrie, MD of The Concrete Institute, provides guidance on how to avoid the effects of unprotected exposure.

24

The composition of Portland cement is such that when dry cement is exposed to water, a chemical reaction called hydration takes place, releasing a very strongly alkaline (and caustic) fluid. This can cause alkali burns and safety measures should be observed. Appropriate precautions are advised to prevent tissue damage when handling fresh mixes containing water and Portland cement.

Cement dust, dusts from handling ag-

REDUCING RISKS OF HANDLING CEMENT

gregates and from cutting concrete are easily inhaled. Prolonged or regular exposure to these dusts should be avoided.

Some risks Portland cement is a complex combination of compounds which include minute quantities of trace elements. Although South African cements typically contain less than two parts per million of hexa-

“Fine silica dusts created when crushing or handling these aggregates could cause lung problems.�

valent chrome (widely regarded as a safe level), it may serve as an aggravating factor in cases of exposure to alkaline fluids.

There have been some reports of allergic dermatitis after exposure to these fluids.

When fresh concrete or its bleed water comes into contact with human skin, the alkalis react with the oils and

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TECHNICAL

Regularly wash (at least daily) protective clothing and keep it clean and free of concrete. Wash any areas that have been accidentally splashed with wet concrete as soon as possible, using large quantities of clean water. Ensure that normal and protective clothing does not become soaked with wet concrete or concrete

25

fluids, as this could result in exposure over an extended period, resulting in tissue damage.

Cement is an abrasive fine powder and, when handled, some dust may be-

Dust particles

come suspended in the air in the working

Many of the aggregates used in concrete

area. Users should avoid inhaling cement

have high silica contents. The fine silica

dust, as this may cause irritation of the

dusts created when crushing or handling

nose and throat. Cement dust may also

these aggregates could cause lung prob-

cause irritation of the eyes. This will

lems and precautions should be taken to

occur because of the chemical reaction

avoid breathing in such dusts.

of the suspended dust with the moist

Dust from demolishing or cutting

fats in the skin, as well as the proteins

mucous membranes. Airborne cement

hardened concrete may contain un-

in it, causing tissue damage. Other or-

dust should be kept to a minimum to

hydrated cement and could cause the

ganic tissue (such as mucous membrane)

avoid these problems. Should this be

respiratory problems outlined above. In

can also be attacked by strong alkalis,

impractical, then the use of goggles and

addition, if the coarse or fine aggregate

leading to burns that can be severe, so

dust masks is strongly recommended.

used in making the concrete contains

users should try to avoid all unnecessary

crystalline silica, then inhalation of these

contact with these fluids. Where such

fine silica particles could expose work-

contact is unavoidable, suitable precau-

ers to the risk of developing silicosis.

tions should be taken.

A concerted effort should be made to

Roughness and dryness of the hands

avoid generating such dusts. If this is not

after working with concrete is a typical

possible, the use of suitable respiratory

consequence of loss of these oils and

protective equipment is recommended.

fats. More prolonged exposure could

Site workers should also not kneel on

result in irritant dermatitis. It is possible

fresh concrete during placing, compact-

that the effects of trace elements may

ing and finishing operations. If kneeling is

aggravate the condition and lead to an

unavoidable, thick waterproof kneepads

allergic dermatitis. To safeguard against

should be worn with a kneeling board

accidental exposure, appropriate protec-

to prevent the pads sinking into the

tive equipment is strongly recommended.

fresh concrete. In severe cases of alkali burns, a medical practitioner should be

Proper precautions Impermeable gauntlet-type rubber gloves and high-length rubber boots should be worn to prevent direct contact with skin.

Trousers should overlap the boots, rather than be tucked into them. Hydrophobic alkali-resistant barrier creams should be applied to the hands and any areas of skin likely to be in contact with fresh concrete. Ordinary barrier creams are likely to be inadequate.

These precautions may be ineffective if the skin itself is not clean and free of concrete residue. Even a tiny trace of cement dust remaining in contact with wet skin will raise the pH significantly. For this reason, some authorities recommend the use of disposable gloves and discourage re-usable ones.

PRECAST | ISSUE THREE | 2019

consulted as soon as possible.

TECHNICAL 26

WHERE TO APPLY MODULAR CONSTRUCTION METHODS In many parts of the world there is a big

SA, we also need to ask how we can

(excluding, of course, the time spent

demand for new housing. To meet the

build acceptable housing units within a

preparing modules at the factory).

backlog, numerous countries have put

reasonable time-frame, with a limited

Yet, even if the shor t assembly

together plans to build a high number

budget, while providing a solid foundation

time sounds great, there are some

of low-cost housing units in a very

for living for the future home-owners

downsides. Room-sized 3D modules in

short time.

and tenants.

precast concrete are heavy and may

“However, all these future housing

“As in all projects, everything starts

weigh more than 30 tons. Handling,

units need to meet a range of different

by defining what an acceptable solution

lifting and transportation of such heavy

demands to be acceptable,” cautions

would be and what such a solution

modules is challenging and may cause

Curt Lindroth, area sales director:

should provide. In this case, the question

damage to the finishing or the structure.

Elematic Oyj, based in Finland. Here in

is about what building method and

The end result is often a situation where

materials to choose,” says Lindroth.

the overall cost per built-up square metre is higher than it would have been

3D modules

using a modern, design-focused precast

He adds that in other markets, there is

system.

a growing interest in manufacturing pre-

Using 3D steel moulds for production

designed standard box unit modules at a

at the factory may be applicable to pre-

factory, as this speed up the assembly

manufacturing of bathroom and elevator

on site. For example, a precast concrete

shaft modules. However, it is important

company in Dubai applied the principles of

to keep in mind just how heav y and

modular construction in a villa project. It

complex precast concrete products can

stretched the 3D design to room-sized

be to pre-manufacture. Architectural

3D modules in precast concrete. The

freedom may be very limited if buildings

modules were assembled at the factory

are completely built using 3D moulds.

using precast concrete panels, including

(Top): Building with precast concrete.

(Above): Curt Lindroth, area sales director: Elematic Oyj.

finishing, electrical cabling, sockets

Modern precast

and plumbing. Additionally, the modules

Moder n, design-f ocused pr ecast

were transported to the site, where

concrete is suitable for all types of

the villa was assembled in only 48 hours

buildings, including in seismic areas and

PRECAST | ISSUE THREE | 2019

Furthermore, pre-stressed hollow-

state-of-the-art production machinery.

concr ete can be used as the main

core slabs save up to 45% in concrete

Automated functions cover planning,

building material or only partly as a

compared with reinforced concrete floor

monitoring and controlling the process

structural component.

cast in a 3D mould, or a plain cast-in-

of producing building blocks for accept-

When high-quality, energy-efficient

situ reinforced slab. Pre-stressing steel

able buildings.

buildings have been the target, modern,

can also be cut by 30% because of the

An acceptable building for a home

design-f ocused pr ecast concr ete

lower self-weight of hollow core slabs.

should, first of all, be affordable and of

has repeatedly been selected as the

In an average apartment, this means

a decent quality, with sufficient living

construction method. Precast concrete

savings of about 14 tons of concrete

space, good structural stability and

is a pr oven, industrialised building

and more than 250kg of steel. Moreover,

located in a sustainable neighbourhood.

method. Even if installation still takes

pre-stressed hollow core slabs can be

An acceptable home needs to match the

place at the construction site, the main

partly recessed, which makes it easier

expectations of future home-owners

part of the work is transferred from the

to prepare bathroom plumbing.

and tenants.

organised factory conditions. In addition,

Optimised production

life-cycle costs of precast concrete

housing units are still completed with-

Modern automated precast concrete

buildings make them an attractive choice

in a reasonable time, cost-efficiently

production plants optimise an entire

for home-owners. Add to that short

and safely.

precast production process, from 3D

construction time and cost-efficiency

The use of precast concrete offers

building design to the construction site.

of the construction process and you

considerable cost-savings, compared

The production lines feature advanced

have an optimal choice for large housing

with alternative solutions. These savings

software, modern table circulation and

projects,” says Lindroth.

chaos of a building site to controlled,

“To sum up, good quality and low

come from a number of sources. For example, in residential buildings, the span of pre-stressed precast hollow core slabs can be 8-12m. The external insulated precast concrete wall panels can work as the only load-bearing walls.

“The use of precast concrete offers considerable cost-savings, compared with alternative solutions.”

Production plants for thin-walled concrete pipes

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• Our packerhead machines are electrical driven resulting in significant higher energy efficiency (up to 30%) compared to hydraulic driven machines.

• Thin-walled pipe design (starting as low as 35mm for a DN300 pipe) results in low production costs and low transportation costs.

• Production cycles as short as 60 seconds give output of more than 400 pipes per shift.

• Automatic production mode secures consistant quality and reduces labour demand.

• No overhead crane required and no specific requirements for the building.

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TECHNICAL

in those prone to tornadoes. Precast

27

TECHNICAL 28

CULVERTS FOR WATER, ROAD AND MINING INFRASTRUCTURE CMA member Rocla is a leading precast

Once-off projects

along w i th the pr e c as t b ase – as

concrete product manufacturer able

Along with custom-designed culverts

opposed to casting in-situ – will save

to supply a wide range of culverts for

for once-off projects, Rocla offers two

on project duration and provide quality

infrastructure and other water flow-

distinct ranges of culverts differentiated

assurances on final product.

related projects.

by the type of loading requirements,

The company has recently drawn attention to the requirement for quality

both available with associated precast

Wingwall units

base slabs.

Rocla’s precast wingwall units can be

products when undertaking new projects,

For heavy loading applications, such

used at both the inlet and outlet of

whether it be for water, road or mining

as to provide a waterway below railway

any channeled system making use of

infrastructure. Its unwavering focus

tracks, Rocla’s SATS SAR rectangular

circular or rectangular portal culverts

on quality, along with technical design

portal culverts can be used. These,

for stormwater applications. The natural

expertise in project assessment and

or custom uni ts, ar e also u tilised

f low p a th o f wa ter upstr e am o f a

product design, has paid off in recent

in any application with excessive fill

construction is often wider than the

times, having been successfully used

requirements, with the culvert tunnel at

culvert or pipe structure. Transition

for custom-designed culverts and many

the base of the fill zone, allowing either

sections are then required to receive

major infrastructure developments, such

conveyor or vehicle access.

and direct the flow of this upstream

as the Polokwane Eastern Ring Road and

T he st andar d S A R cul v er ts ar e

the rehabilitation of the D528 in George’s

supplied in lengths of 1,22m and designed

The same is true of the downstream

Valley, Limpopo.

for up to 10m of fill. Culverts required

end of the culvert or pipe section. The

water through the culvert or pipe.

The main function of culverts is to

for loading heights greater than 10m

precast concrete wingwall unit is the

manage the flow of water from one side to

are handled individually and designed

most effective structure to use for

the other of an “obstruction”. This can be

in-house at Rocla’s head of fice. For

the transfer of this water, eliminating

a road, railroad, trail or other structure

traditional loading applications, creating

erosion and creating a smoother flow.

c ons tr uc t e d in ei ther the na tur al

waterways below roads, trails or even

Rocla manufactures a wide range

or designed flow path of the water.

drainage channels, Rocla’s standard

of precast concrete products which

Factors to be considered before design

rectangular portal culverts are the

are ef fective and cost-ef ficient

and installation are the site-specific

preferred solution.

f or all in f r as tr uc tur e and gener al

application and environmental impact

These standard culverts range in

construction project requirements.

(ensuring that erosion is minimised and

size from a span of 450-3 600mm

It has representation in Namibia and

structural damage avoided). Incorrectly

and heights from 300-3 000mm. The

Botswana, in addition to its South

placed or designed culverts can result in

strength classes for these culverts

African presence.

culverts failing, becoming dislodged and,

are 75S, 100S, 150S, 175S and 200S.

in extreme pollution cases, being clogged

If time constraints are a factor for any

by vegetation and sediment.

project, the precast culvert option,

(Above): Culverts manufactured by Rocla.

PRECAST | ISSUE THREE | 2019

CAMBRIDGE UNIVERSITY RESEARCHES SELFHEALING CONCRETE Researchers at the UK’s University of Cambridge are using micro-encapsulation technologies developed by Dolomite Microfluidics to develop self-healing construction materials. The Department of Engineering’s Geotechnical & Environmental Research Group is developing microcapsules containing “healing” agents – such as minerals, epoxy or polyurethane – which can be added to building materials to allow self-repair of small cracks which develop over time.

Dr Livia Ribeiro de Souza, a post-doctoral researcher in the group, explains: “Many composite building materials used in the construction industry, such as concrete, suffer fatigue over time, developing small cracks. We’re hoping to overcome this problem by adding microcapsules filled with ‘healing’ agents to the concrete before it’s used. The idea is that, as cracks begin to form, they rupture the microcapsules, releasing their payload and stabilising the material.”

Functionalised microcapsules created This approach requires the formation and functionalisation of double-emulsion microcapsules, which the scientific team has been producing with the help of microfluidics. The researchers have been using a Dolomite Microfluidics system since 2014, and find that it offers much better control of particle size and composition than traditional emulsification polymerisation techniques, simplifying the investigation and optimisation of particle properties.

The Dolomite system has enabled the researchers to create functionalised microcapsules that bind more strongly to the cement matrix, while also having thinner shell walls and higher core retention, improving their self-healing properties. “It’s good to be able to discuss any issues we’re having with the experts at Dolomite Microfluidics, helping to accelerate our research and move us a step closer to real-world applications,” says Ribeiro de Souza.

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

Surpassing 100 years of product excellence.

• • • • • • •

Pipes Culverts Manholes Poles Retaining walls Roadside furniture Sanitation

Including other related products within infrastructure development and related industries.

Visit us on

(Above): Dr Livia Ribeiro de Souza using a Dolomite Microfluidics system. (Figure: Dolomite Microfluidics)

PRECAST | ISSUE THREE | 2019

www.rocla.co.za

for our nationwide branches

INSTALL

CERTIFIED

PRECAST CONCRETE

PRODUCTS

TO OBTAIN A LIST OF CERTIFIED SUPPLIERS, CONTACT CMA CERTIFICATION SERVICES OR VISIT WWW.CMA.ORG.ZA.

Address: Office 0400, Standard Plaza Building, 440 Hilda Street, Hatfield, Pretoria, 0083 Tel: (011) 805 6742 • Email: admin@cma.org.za

IF YOU THINK PRECAST CONCRETE, THINK CMA

A

N

UF

ACTURER

S A OCI

NCRETE

SS

M

PRODUCER MEMBERS.

CO

AT I O N

al

t

e

Q

u

it

y c nc a s t in c o

re

Address: Office 0400, Standard Plaza Building, 440 Hilda Street, Hatfield, Pretoria, 0083 Tel: (011) 805 6742 • Email: admin@cma.org.za • Website: www.cma.org.za

TECHNICAL 31

REBEL WITH A CAUSE: HOW SEEKING PERFECTION PAYS SA’s construction industry is under

Howe v er, f a te inter v ened when he

huge pressure and some of its largest

missed the apprentice enrolment date

His time with SAR and subsequent

companies have gone belly-up. Those who

with Cummins Diesel, and he found

employment were frustrated by several

have stayed the course tend to be fleet of

sanctuar y with (then) SA Railways

army training camps. After his first

foot and better able to adjust to a much

(SAR), where his duties did little to fulfil

stint in uniform, he thought he couldn’t

harsher macro-environment.

his mechanical aspirations: he was a

go far wrong with mining and found

forklift washer, steam engine stoker and

employment on one of the Free State

One survivor is Cape-based precast

electric train-driver assistant.

concrete manufacturer and steel

gold mines as a mine cage onsetter on

fabricator David Timothy. Having always

a shaft which plunged a staggering 4km

valued quality above quantity, Timothy

below the surface.

has used this philosophy to establish

In the wake of his second army camp,

three successful businesses: Cobble

he succeeding in indulging his passion for

& Slab – precast concrete production,

vehicle maintenance when he was offered

Hamblin Engineering – steel fabrication and precast concrete mould production, and Hope Gar den Furnitur e cc – a manufacturer of Edwardian café-styled pavement furniture of global repute.

Shunning convention and orthodoxy, Timothy’s achievements have been built on a quest for perfection, exceptional engineering ability, versatility and selfreliance. Before he ventured on his own in 1988, he acquired invaluable, wide-ranging expertise with several engineering enterprises and it was this that gave him the can-do confidence and flexibility which have underpinned the development of his three diverse, yet inter-related businesses.

Early days When he left school in 1970, Timothy had his sigh t s se t on b e c oming a very good mechanic like his father.

PRECAST | ISSUE THREE | 2019

(Above, from left): David Timothy stands next to some freshly cast kerbs; pre-stressed Vibracrete posts.

(Lef): Part of a patio furniture consignment destined for a castle in Spain.

(Below): Cobble & Slab’s storage yard.

TECHNICAL 32

an apprenticeship at a garage workshop

department. In 1983 he was transferred

The first breakthrough came when Marine

in the old Karoo town of Colesberg. This

to Concor’s engineering workshop in

Civils awarded the company the contract

is a period he looks back on with special

Cape Town, where he was put in charge

to manufacture the Gordon’s Bay floating

fondness, because not only did he revel in

of estimating and draughting. During his

jetty, which was manufactured on Libra

the work, but he met and fell in love with

time with Concor, Timothy was intimately

Construction’s premises in Somerset

a Mauritian girl. When she returned to

involved with some of the company’s

West. Timothy had to improvise by using

her home town of Bonaero Park in 1973,

major contracts, including the building

a gantry attached to a neighbour’s wall.

he gave chase – and they were married

of the Matimba Power Station and

soon afterwards.

the supply of steel formwork for the

Steel specialisation A year later, the business relocated

New career Now a husband needing to put food on the table, Timothy found employment as a welder at the first engineering workshop he approached, Engineering Design & Construction (EDC). Two years and another SA Defence Force camp later, he was appointed as a welder with

“The early days were tough and it took several years before the furniture business turned a profit.”

Pimbro Engineering. After another six

to rented premises at SBDC premises in Blackheath, Cape Town, star ting with 100m². As the company grew, its premises expanded to 1 100m².

Another breakthrough came when George Cocotos of Libra Construction awarded Hamblin Engineering some structural steelwork. Thereafter, the company began manufacturing precast concrete moulds

weeks of border patrolling, he rejoined

construction of the Du Toitskloof Tunnel

for other precast concrete producers

EDC and – within three months – was

on the N1 between Paarl and Worcester.

such as Cape Concrete, Concrete Units

In 1988, he felt the time had come to

and Rocla. Mor e r ecently, Hamblin

He left EDC for the second time in

launch his own steel fabrication business,

Engineering designed and made all the

1978 to join Concor Construction’s

Hamblin Engineering. Operating out of

component parts for a conveyor system

Johannesburg-based steel fabrication

his garage in Somerset West, he began

at a crockery factory in Blackheath.

workshop as production foreman of

by manufacturing burglar-proofing, steel

In 1992, Timothy was approached by

the cast-in-situ bolts and steel items

gates and other small steel products.

Adrian Hope, who enquired whether a bar

running the workshop.

www.smartstone.co.za

Design

You can

with

of mild steel could be forged and twisted

and Asia. At the time of writing, a large

into an attractive shape. Not having

consignment was being prepared for ship-

done this type of work before, Timothy

ment to a privately owned castle in Spain.

nevertheless accepted the challenge, knowing it wouldn’t take him long to

Next venture

perfect the technique. He didn’t hear

Cobble & Slab was started by Timothy’s

from Hope until six months later, when

son, Shane, who began making wet-cast

the latter approached him again, this

concrete pavers in three sizes. This was

time with a firm order to manufacture

followed by the production of kerbs and

twisted steel frames for the café-style

panels for Vibracrete walling.

pavement furniture mentioned above.

“We then installed a stressing bed

Using a plough shear as a homemade

and began making pre-stressed posts

f u r n a c e, T i m o t h y ’s s t e e l f o r g i n g

for the Vibracrete walling. Again, quality

methodology was more akin to a

was paramount and we adopted the

blacksmith’s forge than a modern steel

same approach to our precast concrete

plant. Long a collector of pre-war heavy-

production as we did to our furniture

duty steel fabrication machinery, Timothy

and steel fabrication businesses. As a

was able to put this antiquated plant to

result, many of our early Cobble & Slab

work and became a supplier of meticulous

customers are still with us. And if we’re

forged metalwork which characterises

unable to supply immediately, our clients

the Hope product range. Part of the

prefer to wait until we can deliver, rather

production process involved making hand-

than buying elsewhere,” he says.

operated jigs for turning out curves and

Although kerbs and Vibracrete walling

scrolls. He also adapted a large pre-war

are the mainstays of Cobble & Slab’s

lathe, which had probably been used for

output, the company will make any

the manufacture of tank parts during

precast concrete product to order.

World War II, to produce metal table-tops.

Besides supplying hardware stores and building contractors, the company also

Making furniture

produces precast concrete products

This manufacturing approach was, as

such as lintels, manholes, various pavers

Timothy readily admits, outdated and

and trench covers for some of the

slow, but it delivered a very high-quality

Western Cape’s larger precast concrete

product which fulfilled his operational

producers.

philosophy of striving for perfection. Three months after he began manufacturing pavement furniture, Timothy became a partner in what is today Hope Garden Furniture cc.

He says the early days were tough and it took several years before the furniture business turned a profit.

“Fortunately, we were able to crosssubsidise the furniture venture from our steel fabrication and concrete mould production activities and, many years later, from Cobble & Slab, which we began in 2008. Despite a slow start, we never lost faith in what we were doing; nor did we lower our pavement furniture standards. For example, we’ve always used only sustainably forested imported hardwoods for our table-tops and chair linings. Maintaining a consistently high standard is what enabled us to break into the export market,” says Timothy.

Hope Garden Furniture’s first export consignment was for a public park in Florence, Italy. Subsequent exports have been

(Above): Some of the café-styled pavement chairs flanked by Roscoe Dean (left) and David Timothy.

to many foreign destinations in Europe

(Below): Wet-cast kerb production.

PRECAST | ISSUE THREE | 2019

PROJECTS 34

PRECAST IN BOUTIQUE WINERY CON Precast concrete has played a crucial role in the construction of a new winery at Cordoba, a wine estate situated on the lower slopes of the Hottentots Hollands mountain range just outside Stellenbosch.

Scheduled to process the 2019/ 20

civil engineers), Hennie Kleynhans QS

“One o f our big challenge s was

h a r v e s t, t i m i n g a n d t r o u b l e - f r e e

(quantity surveyors), CSV Construction

c on v er ting the war ehouse in t o an

construction were crucial elements in

(main contractors) and Cape Concrete

integral part of a hi-tech winery. Apart

the early viability of the estate. Cordoba

(precast concrete producers).

from the roof, it was completely gutted

was bought in 2017 by a European

According to Charl de Kock of consultC

consortium on the strength of its ideal

Engineering, meeting all the building and

The upper level of the new building will

soil, cool climate and the outstanding

plant assembly deadlines was vital to the

be used for the early wine-making stages,

quality of its grape varietals. The latter

success of the project.

such as grape-crushing and initial cooling,

will be crafted into exceptional boutique-

and rebuilt,” says De Kock.

“Our schedule was simpl y too

and the lower ground-floor section for

tight to allow for any changes during

maturation and ageing. In addition, a

Process engineering was the focal

construction. Precast assisted us in this

double-storey brick-and-mortar office

point of the project and every element,

regard, which is why we planned its use

building was erected adjacent to the

from the wine processing equipment to

from the outset. Moreover, it’s easier

crushing plant on the upper level.

the precast concrete elements, was

to program and eliminates rain delays,”

custom-designed. This not only meant

he says.

quality wines.

A large volume of earth had to be shifted to create a platform for the

trouble-free construction and plant

new building which has been built on the

assembly, but also proved to be the most

same level as the existing warehouse.

cost-effective option.

The excavation left a soil embankment approximately 7m high, which had to be

Professional input

retained. Rather than build a separate

Unlike many construction projects which

retaining wall, the rear wall of the new

only unearth problems on site and are

structure and half of one of the gable-

then costly to remedy, the planning on

end walls doubled as retaining walls. In

this project accounted for the smallest

addition, half the opposing gable-end

detail and took two years. This is why, when it is completed in February 2020, actual construction and plant assembly will only have taken a year.

The project began with the appointment of Schalk Willem Joubert, one of the country’s most experienced winemakers as its managing director, and subsequently a team of professionals with the enviable reputation of having

“The advantage is that once the columns are grouted in position, the props can be removed within 24 hours.”

brought the recently-completed Rupert

elevation was also constructed using precast slabs in order to maintain the building’s architectural symmetry.

Upper level T he retaining walls were built with precast panels measuring 7m x 2,4m x 345mm and the void between the walls and embankment was filled with soil and then compacted. The remaining halves of the gable-end walls and the opposing/

& Rothschild Classique Winer y and

Moving earth

some other high-end winery ventures

The 1 600m² winemaking plant has been

on stream. The professional line-up

built on sloping land at the bottom end

is as follows: consultC Engineering

of the estate. It comprises a 1 000m²

(process engineers and principal agents),

twin-storey processing plant and cellar

M a l h e r b e R u s t A r c h i t e c t s, M P r o

which has been attached to an existing

Consulting Engineers (structural and

600m² warehouse.

warehouse elevation wall were built using (Top from left): A precast panel with two protruding feet for vertical alignment; some of the oval columns prior to the assembly of shuttering for the first floor and some of the precast columns at Cape Concrete’s production yard.

(Above): One of the column concrete bases showing the templates for rebar alignment.

PRECAST | ISSUE THREE | 2019

NSTRUCTION

considerable amount of time to finetuning our precast designs before the first moulds were built – and having Cape Concrete on board from the outset made

conventional brick-and-mortar masonry

this process much easier. Once the

between the columns.

moulds were made, it was just a matter

A considerable advantage of this

of repeated casting.”

winery’s design is that the upper floor

Structural engineer Henk Burger

and the top of the embankment are level,

of MPro Consulting says the precast

which means grape-laden containers and

panels were installed using inverted

other vehicles can be wheeled directly

construction. This involved first casting

off the embankment onto the upper floor

a blinding layer and then lifting the panels

without the need for an access ramp.

into position with a 130-tonne mobile

Furthermore, the design provides the

crane. Each panel was cast with two

necessary gravity required to move the

360mm x 345mm feet at the bottom

crushed grapes from the upper level to

end, flanked with starter bars. The feet

the ground-level processing section.

came to rest on the blinding layer and

The upper level floor comprises a

steel shims were inserted under them

reinforced in-situ structure supported

for vertical alignment. Once foundation

by 32 6m-high oval precast columns.

reinforcing had been installed, concrete

“Aesthetically pleasing finishes were

was poured around the base of each

important project elements, which was

panel, which remained propped until the

why we opted for oval columns,” says

upper floor section had been cast.

De Kock. “They’re more easily produced with precast manufacture and the nice

Accurate building

thing about them is that when looked at

“The only downside to this approach

side-on, they appear to be only 140mm

was that we had to prop the walls a

thick. And, of course being precast, their

little longer than usual, due to the walls

quick installation enabled the upper floor

being designed as propped cantilevers,”

level to be cast much sooner.”

says Burger.

Precast solution

each vertical joint. These formed ducts

“Given our time constraints, this project

for grouting the panels together.

The panels were also cast with keys on

would have been impossible without the

“It’s much easier to build accurately

use of precast concrete,” says Servaas

with precast walls. Not only is it more

de Kock of Malherbe Rust Architects.

difficult to achieve the same accuracy

“A major advantage is that it can be

with in-situ construction, but it’s also

produced while other building activities

much more time consuming, given that

are underway, which saves time. It may

precast elements can be manufactured

appear more expensive than in-situ on

while preparation work and foundations

a direct item-for-item basis, but when

are continuing on site. Moreover, with

time-saving, quality, reliability and safety

in-situ, every shutter board can be out of

aspects form part of the equation, it

line, so the chance of error is far greater.

wins hands down.

By contrast, in the unlikely event of a

“One of the main challenges in using

precast panel or column not meeting

precast is keeping it modular. We could

design specifications, it can simply be

have opted for innumerable shapes

exchanged for another,” explains Burger.

and sizes, but that would have proved

A dif ferent method was used to

too expensive. Instead, we devoted a

install the columns. They were cast with

PRECAST | ISSUE THREE | 2019

PROJECTS 36

corrugated grouting ducts, rather than

curing, the entire slab was covered with a

columns, there is a third precast and

protruding rebar and were lowered onto

layer of water for 10 days to ensure even

equally important concrete element in

starter bars set in concrete bases and

curing and no cracking. The shuttering

this project: precast concrete wine

then grouted in position.

was only stripped off the deck once the

tanks. Imported from Italy, 10 tanks

concrete was fully cured.

were initially fitted for the first season,

“The advantage of this process is that once the columns are grouted in

Special hard-wearing ceramic tiles

position, the props can be removed within

imported from Germany were used to

24 hours,” says Burger. “However, the

line the floor. To avoid air pockets, they

grouting ducts had to be cast with a

were laid as an integral part of the floor

Fast work

tight tolerance of 2-3mm so that they

structure on a 100mm cementitious

De Kock says concrete wine tanks exhibit

but the aim is to have 36 tanks installed and ready for the next harvest.

could match the starter bar alignment.

far fewer temperature fluctuations than

A nd Cape Concr ete supplied CSV

their stainless steel equivalents, which

Construction with steel templates to

display hot and cold spots.

ensure that the starter bars were cast

“Quality gains using concrete tanks

with the required degree of accuracy

are huge. Stainless steel tanks are

to match the column ducting. Once in

better suited to the initial fermentation

position, the columns were vertically

pr o c ess w hen the w ine’s mo v ing,”

aligned with fibre-cement shims.”.

explains De Kock.

Waterproof floor

will be fully functional by the end of

In order to ensure that the plant One of the major considerations in the

(Above): Precast retaining walls and columns.

February, some of the wine processing

construction of the winery was that

screed. Rated at 35MPa, the screed

equipment was installed in September,

the upper-level floor had to be 100%

was sloped to create falls to stainless

even though not all the building work had

waterproof and it was designed to comply

steel drainage slots so that solids

been completed. Other aspects of the

with that proviso. Cast in- situ with

can be washed off the floor. The tiling

project – such as the building of roads,

high-strength reinforced concrete, the

was done by highly skilled artisans who

the upgrading of water and electricity

floor has a loading capacity of 16kN, or

created channels between tiles for

supply and installation of Wi-Fi – all took

1,6 tonnes per square metre, and binds

water drainage.

place in tandem with the construction of

together with the walls. After the initial

Besides the pr ecast panels and

the winery.

PRECAST | ISSUE THREE | 2019

SUSTAINABLE STORMWATER DRAINAGE AT KIRSTENBOSCH A sustainable stormwater management system and the creation of an attractive paved environment were prime design considerations during a recent upgrade of landscaped areas around a new administration centre at Cape Town’s Kirstenbosch National Botanical Garden. Built on the northern side of the main entrance to the national heritage site for the SA National Biodiversity Institute (SANBI), the new centre houses offices for the institute’s finance, HR and IT departments.

The main objective of the stormwater

comprising Vernon Mathews of VMA

system was to control water surges

Architects (the project’s architects and

during heavy downpours. It entailed the

principal agents), project manager Amjad

construction of two attenuation ponds,

Hendricks of Aurecon and environmental

a 340m² permeable interlocking concrete

consultant Jer emy Rose of Inf inity

paving (PICP) parking lot and shoring up

Environmental.

some water courses with gabions.

A high-powered team was assembled to design and implement the project,

Aesthetic appearance According to Mathews, the essential purpose behind the landscaping was the creation of an attractive environment in sync with the rest of the garden’s driveways and parking areas. It involved extensive use of exposed aggregate paving, permeable interlocking pavers and grass block paving – all supplied by CMA member, CEL Paving.

The exposed aggregate paving was used to repave some 200m of existing asphalt access roads and a 600m network of existing pathways. CEL Paving’s interlocking permeable pavers were used for the PICP parking lot and the company’s grass block paver was laid on (Left, from top): The parking lot paved with CEL Paving’s interlocking permeable pavers and some of the paths paved with CEL Paving’s exposed aggregate and grass block pavers.

PRECAST | ISSUE THREE | 2019

PROJECTS

some of the other parking areas, paths and a bus shelter.

“We specified the CEL Paving exposed aggregate pavers because of their high level of consistency in colouring and texture,” says Mathews. “The new pavers are identical to CEL Paving’s exposed

38

aggregate pavers, which were installed on some of the Kirstenbosch driveways and parking areas six years ago and blend in seamlessly with them.”

Pond overflows The newly-paved roads were cambered with falls that drain into open-paved channels on both sides. The channels drain into catch-pits which, in turn,

(Above): Part of the access road paved with CEL Paving’s exposed aggregate pavers. The road is flanked by open drainage channels and a small parking lot paved with charcoal-coloured grass blocks.

feed the attenuation ponds via precast concrete pipes. The ponds are linked via a

is full, it discharges into the municipal

subterranean concrete pipe so that when

stormwater system.

aggregate pavers.

The PICP parking lot was designed by

the first pond overflows, water drains

Most of the water which falls or drains

Orie Welby and Solomon and comprised

into the second. When the second pond

onto the permeable paving parking lot

a sub-base layer of F50 geotextile (to

infiltrates into the soil. However, during

keep the sand off the bottom layer of

heavy downpours, fin drains channel ex-

aggregate), 250mm of 53mm aggregate,

cess water into a catch-pit which feeds

150mm of 19mm aggregate, a layer of

into the lower attenuation pond.

Fibertex F25, a 6mm layer of bedding

The walls of the attenuation ponds were constructed with gabions filled with

sand, CEL Paving’s interlocking permeable pavers and filler stone.

locally excavated rock, while the bottom

In addition to VMA Architects, other

of the ponds were lined with Armorflex

members of the landscaping professional

blocks supplied by CMA member Inca

team comprised Arwin Bhawan (land

Concrete Products.

su r v e y o r s ), O r r i e We lb y, S o l o m o n & A ssociaISSUtes (ci v il and str uc tur al E TWO

• 2018

Permeable paving

engineers), OVP Associates (landscape

Considerable time, money and resources

a r c h i t e c t s ), M a r t i n & E a s t ( m a i nR49.00

were saved in the paving of the access

contractor) and HC Pav ing (pav ing

road. This was due to an existing sub-

contractor).

THE CM

A – QU

ALITY

CAST

base of 150mm G5 and 150mm G4 aggregate, which was retained. The only fresh material required was a 6mm layer of bedding sand for the exposed

IN CO

NCRET

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(Left, from top): A section of road paved with CEL Paving’s exposed aggregate pavers and the lower attenuation pond lined with gabions and Armorflex blocks supplied by Inca Concrete Products.

ISSUE

TWO

• 2017

UALITY

A–Q

THE CM

VISIT IS SUU.CO M AND SE ARCH PRECAS T MAGA ZINE FOR CU RRENT AN D BACK IS SUES ISSUE

ONE

• Wor ld beat ing blo • 3D ck ma printed ker house • Exce llence on dis play

CAST

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IN CO

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• 2018

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winners ges Award challen • CMA omic tures g econ or struc • Easin convey tion of • Evolu

THE

WANT TO ADVERTISE? CONTACT THULI MAJOLA TEL: 011 883 4627 OR EMAIL: THULI@ISIKHOVA.CO.ZA

PRECAST | ISSUE THREE | 2019 lls g wa tainin s een re r cost • Gr rpiece s lowe ator maste ural • Vibr itect arch • An

CMA

– QU

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CON

nical experience and product application analysis, was selected to design and manufacture skew culverts for the Parktown Emergency Stormwater Project in Johannesburg.

“A n assessment of the r elevant technical and practical factors is key to the successful design of any element

REHABILITATION OF PARKTOWN

STORMWATER SYSTEM Concrete stormwater pipes have a long lifespan, but it is not infinite. Ageing infrastructure, as well as pipe erosion and corrosion. are all factors that initiate the rehabilitation of stormwater piping systems.

of stormwater rehabilitation projects,”

a curvature that would fit properly into

says civil engineer Muhammad Bodhania,

the existing curved channel. We’re proud

based at Rocla’s Roodepoort offices.

to say that despite the challenges of

“There were numerous technological

the required angle design, we met the

challenges presenting on the Parktown

technical specifications completely”.

project, so meetings were held be-

Rocla supplied 42 straight 2 500mm

tween PGN Civils, the site engineer

x 2 500mm SAR culverts, 19 skew

and ourselves in order to ascertain the

culverts and associated bases.

most appropriate design and product

“We’ve worked with engineers at PGN

to be used for the successful insta-

Civils and WBHO previously on specialised

llation of the replacement skew culverts

projects and they know about our techni-

and bases.

cal, design and manufacturing capabilities,

“The existing stormwater channel

which was why Rocla was chosen to as-

at Parktown has a unique curvature, so

sess and resolve the technological chal-

Rocla had to design and manufacture

lenges of a unique project,” adds Bodhania.

specialised skew culverts that could

The Parktown Emergency Stormwa-

be installed into it. We took the basic

ter Rehabilitation Project started in

design of a standard Rocla culvert, but

February 2019 and is due for completion

manufactured it at an angle to create

in February 2020.

PRECAST SPECIFIED FOR ATTENUATION POND CMA member Technicrete’s erosion con-

runs smoothly on site. Upon excavation of

flexible and sophisticated in design, con-

trol system, which provides an alterna-

the pond’s designated area, unexpected

forms to ground contours (even if set-

tive for a wide variety of erosion control

rock was discovered which had to be

tlement occurs after installation – the

and drainage projects, was recently

removed with chemical blasting before

blocks have a specially tapered design to

specified for a specialised attenuation

the required pond level could be reached.

allow for this flexibility), settles without

pond for waste management company

We halted deliveries of the loose blocks

fracture and requires only limited ground

EnviroServ’s Rosslyn premises.

to site until the blasting issue had been

preparation,” added Van der Berg.

Its Armorflex was used as a lining for drainage channels at aprons, pipe inlets

resolved,” said Luan van der Berg, sales consultant for Technicrete.

Technicrete manufactures the internationally licensed Armorflex system in

and outlets, where it eliminates pipe

“We supplied 7 000m² of blocks for

SA. It is the only system available lo-

undercutting that can lead to severe

the attenuation pond, which will serve as

cally with the facility to wire-tie adjacent

problems such as surrounding bank fail-

a storage for run-off dump water and any

blocks together into long mats. The inter-

ure and siltation downstream.

other excess water components at site.

locking design allows the surface to re-

The Rosslyn project ran from Febru-

The product was supplied in palletised

main flexible to movement, eliminating the

ary-June 2019 and was undertaken by

loose-block form for manual installation,

cracking and spalling issues that plaque

MK Africa Civils. “We’ve worked with MK

which – upon completion – created the

solid concrete surfaces, even when

Africa Civils on other projects, and we

mat formation.

exposed to regular inclement weather.

understand that at times, not everything

“The beauty of the system, is that it’s

The openings in each block and between blocks are perfectly sized to benefit from enough vegetation growth to make the surface appear “natural”, while still maintaining structural integrity.

It is suited to other drainage applications such as ditch linings, spillways, headwalls, sediment basins and traps, pipe inlet protection and protective barriers.

PRECAST | ISSUE THREE | 2019

PROJECTS

CMA member Rocla, known for its tech-

39

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SARMA TEL: (011) 315 0300 PROVINCE/COUNTRY: JHB SEKHUKHUNE & ASSOCIATES TEL: (012) 346 1945 PROVINCE/COUNTRY: PTA TACO VOOGT CONSULTING ENGINEER TEL: (012) 669 0125 PROVINCE/COUNTRY: PTA YOUNG & SATHARIA CONSULTING CIVIL ENGINEERS TEL: (031) 207 7252 PROVINCE/COUNTRY: KZN CONTRACTOR MEMBERS

HAWKEYEPEDERSHAAB TEL: 00 459645 4193 PROVINCE/COUNTRY: DENMARK

BUFFALO RETAINING WALLS CC TEL: (016) 366 1801 PROVINCE/COUNTRY: GAUT

KERNEOS SOUTH AFRICA (PT Y) LTD TEL: (011) 444 3090 PROVINCE/COUNTRY: GAUT

DECORTON RETAINING SYSTEMS (PT Y) LTD TEL: (021) 875 5155 PROVINCE/COUNTRY: WC

KOBRA MOULDS B.V. TEL: 003111 356 2460 PROVINCE/COUNTRY: NETHERLANDS MANITOU SA (PT Y) LTD TEL: (011) 975 7770 PROVINCE/COUNTRY: JHB PAN MIXERS SA (PT Y) LTD TEL: (011) 578 8700/8600 PROVINCE/COUNTRY: JHB QUANGONG MACHINES CO LTD TEL: +865 958 679 9557 PROVINCE/COUNTRY: CHINA REVARO CONCRETE EQUIPMENT TEL: (011) 794 827 PROVINCE/COUNTRY: JHB SIKA SOUTH AFRICA (PT Y) LTD TEL: (031) 792 6500 PROVINCE/COUNTRY: KZN TERRAFORCE (PT Y) LTD TEL: (021) 465 1907 PROVINCE/COUNTRY: WC

FRICTION RETAINING STRUCTURES (PT Y) LTD TEL: (011) 608 4321 PROVINCE/COUNTRY: GAUT POWERGATE CONSTRUCTION CC TEL: 071 603 5070 PROVINCE/COUNTRY: GAUT VALCAL INTERNATIONAL EXPORT CC TEL: (011) 867 2471 PROVINCE/COUNTRY: GAUT CEMENT MEMBERS AFRISAM SOUTH AFRICA (PT Y) LTD TEL: (011) 670 5500/5752 PROVINCE/COUNTRY: GAUT SEPHAKU CEMENT (PT Y) LTD TEL: (012) 684 6300 PROVINCE/COUNTRY: GAUT

PI – Precast Infrastructure PB – Precast Building

ASSOCIATE MEMBERS AF CONSULTING ENGINEERS & ASSOCIATES (PT Y) LTD PROVINCE/COUNTRY: JHB

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

ASPASA TEL: (011) 791 3327 PROVINCE/COUNTRY: JHB

on tel: (011) 805 6742.

PRECAST | ISSUE THREE | 2019

The key solution to finishing concrete surfaces

CHRYSOÂŽFiniSafe CONCRETE FINISHING AID

Extends and facilitates the workability of the concrete surface.

Lubricates concrete surface for an easier, faster and better finish.

Reduces floating/troweling and blade wear.

Facilitates dry shake hardeners application.