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ISSUE ONE • 2019

R49.00

THE VOICE OF THE PRECAST CONCRETE INDUSTRY

• PMSA invests in quality • CMACS takes off • UCT to research drainage


GLOBAL VIEW

3 PMSA – BUILT TO LAST

19 WEAR DEVELOPMENT

INDUSTRY NEWS

TECHNICAL

6

MANUFACTURERS SWITCH TO CMACS CERTIFICATION

7

AWARD OF EXCELLENCE

8

RAISING ABOVE THE PACK

9

FINDING ECONOMICAL USES FOR COAL ASH

22

10 OBITUARY: JOHN SIMPSON

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CONTENTS

COVER STORY

33 34 FIRST GREEN HOUSING SOLUTION IN PRETORIA 35 PAVING POLOKWANE RESIDENTIAL AREA

26 AIR-PURIFYING CONCRETE

37 METRORAIL SAFET Y WALL

PROJECTS

38 LOCAL WINE PRODUCERS SWITCH TO CONCRETE FERMENTATION TANKS

27 PERMEABLE PARKING SPACE FOR SHOPPING MALL 28 PRECAST CONCRETE PANELS FOR V&A URBAN PARK

39 CAST-STONE PAVERS SELECTED FOR CAPE HOUSING

30 CARBON FIBRE PLATES STRENGTHEN ROOF SLABS

PRODUCTS 13 CONCRETE WITH CRACK HEALING PROPERTIES

40

15 SOFTWARE MAKES CRB WALL CONSTRUCTION EASIER

COMPANY NEWS

31

16 GATEWAY SCHOOL PUPILS LEARN THE ART OF CONCRETE 17 NEW SHOWROOM TO CELEBRATE 25TH YEAR

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 Publishing & Communications Postal Address: PO Box 651793, Benmore, 2010, South Africa Tel: (+27 11) 883 4627 Fax: (+27 11) 783 2677 Website: www.isikhova.co.za Publisher: Andrew Meyer Tel: (+27 11) 883 4627 E-mail: andrewm@isikhova.co.za Consulting editor: Raymond Campling Tel: 076 297 2775 E-mail: media@mediasavvy.biz

PRECAST | ISSUE ONE | 2019

41 DRONES MAY BE THE ANSWER TO RESOLVING DISPUTES 42 LOCAL MOULD MANUFACTURER CRAFTS WINNING FORMULA

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

ISSUE ONE • 2019

R49.00

THE VOICE OF THE PRECAST CONCRETE INDUSTRY

Advertising: Linda Meyer Cell: 083 626 8814 E-mail: linda.precast@gmail.com Subscriptions/Accounts/ Advertising Admin: Thuli Majola Tel: (+27 11) 883 4627 E-mail: subscriptions@isikhova.co.za • PMSA invests in quality • CMACS takes off

Design and layout: Joanne Brook E-mail: joanne.studio@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:

• UCT to research drainage

ON THE COVER PMSA is a privately-owned company which places a strategic importance on development. Its latest acquisition of high-tech equipment, facilities and skills is in line with its objective of building lasting relationships with customers that are based on the provision of quality equipment, efficient aftersales service and professional technical expertise.

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COVER STORY

While market conditions in the South African construction industry have been undeniably tough, the country’s leading concrete equipment manufacturer, PMSA (CMA non-producer member), has used the quieter times to expand its facilities to meet future demand.

3

During this period, the company has invested in the expansion of its own in-house metal service centre, including the acquisition of the largest fibre laser-cutting machine on the continent and fabrication equipment, as well as expanded workshops and auxiliary equipment. Simultaneously, it has bolstered its own in-house skills base to build upon its extensive after-sales services, which are key differentiators in an increasingly heavily traded market. PMSA director Walter Ebeling says the privately-owned company has always placed strategic importance on development and that the acquisition of hightech equipment, facilities and skills is in line with its objective of building lasting relationships with customers that are based on the provision of quality equipment, efficient after-sales service and professional technical expertise. Looking forward “We’re constantly looking ahead and improving the way we do business so that we remain ahead of the field in terms of

PMSA – BUILT TO LAST

our overall offering. In order to do so, we invest in quality equipment, quality processes and quality staff to ensure that our equipment will last a lifetime and will always be supported. In this way, we build relationships that last a lifetime too,” says Ebeling. “PMSA wants customers to form relationships with us where their needs are being met in every way, including production objectives, price per unit,

“We invest in quality equipment, quality processes and quality staff to ensure that our equipment will last a lifetime.”

(Above): Carefully welding components. (Below, from left): The showroom; PMSA installed the largest fibre laser-cutting machine on the continent.

availability, adaptability and everything else that’s important to each individual concrete manufacturer. “The company still has clients whose parents bought equipment from our parents 40 years ago. Those relationships are still going strong, as are many of the original machines. What’s important is that we know what our customers need now and what they might need in future. We therefore need to research and develop products and services that meet their expectations going forward. Customer-centric “Whether it be building custom machines for a client or creating financing deals

PRECAST | ISSUE ONE | 2019


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

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UF

ACTURER

S A OCI

NCRETE

SS

M

PRODUCER MEMBERS.

CO

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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


COVER STORY 5

(Above): PMSA holds more than R28 million worth of spares. (Top right): One of the company’s high-definition laser-cutters. (Right): Laser-cutting of oversize components is no problem.

to help them improve the quality of products, or even structuring deals that enable our customers to grow and prosper, that’s what we do best and want to continue doing. No other concrete equipment manufacturer in the country can boast the same gravity as PMSA, nor the same levels of customer service. “You can’t put a price tag on quality after-sales and support. PMSA is about quality manufacture and a large stockholding of spares and parts throughout the country. We’re also the only concrete equipment manufacturer that employs

He adds that PMSA pays careful

its own highly skilled, mobile field service

attention to helping businesses grow

teams throughout the country and around

through various life-cycles, from the

the world, wherever our machines are in

start-up phase through to automated

operation. Several of our field and support

operations and serving the biggest con-

staff have more than 20 years’ experience

crete manufacturers on the continent.

at PMSA with our equipment range. We solve the problems facing the market and

Developing opportunities

deliver equipment and services to meet

The investments by the company are part

changing requirements,” says Ebeling.

of the PMSA Built to Last™ business philosophy, which views the company as the market thought leader and largest single concrete equipment provider on the continent, building relationships and machinery that will endure for decades. This type of dedication to improving customers’ bottom lines is unique and underscores the importance for concrete manufacturers of keeping up to date with developments in the industry and upgrades of equipment in order to stay ahead of the pack.

PRECAST | ISSUE ONE | 2019

(Above): PMSA’s flagship Ultra-3000. (Left): P2000 mixers ready for dispatch to Middle East.


INDUSTRY NEWS 6

PRECAST CONCRETE MANUFACTURERS SWITCH TO CMACS CERTIFICATION Steadily growing numbers of precast

& Good Laboratory Practices Act of

concrete manufacturers are placing their

2006. This means it’s totally compliant

trust in Concrete Manufacturers’ Asso-

with the law and is fully equipped to audit

ciation Certification Services (CMACS)

and assess precast concrete products

for the certification of their products.

in line with internationally recognised

“CMACS offers the precast concrete

best-practice standards. The service

manufacturer a reliable SANAS-approved

itself is audited annually by SANAS

certification and quality auditing agency,”

and a committee comprised of external

says Henry Cockcroft, CMACS director

professionals ensures that its activities

and general manager of the Concrete

remain impartial.”

Manufacturers’ Association NPC (CMA). “It also provides a valuable service to

Quality certification

professionals who can now have direct

CMACS certificates are valid for three

access to the people involved in the

years and companies are audited twice

certification process.

annually. The process begins with a to-

“A major advantage of CMACS is

tal system audit. Quality management

that it specialises in precast concrete

systems such as ISO are checked and

certification and all its personnel are

validated, as are testing procedures and

professionals intimately acquainted with

documentation. Thereafter, product test-

motivation/specification is drafted by the

the various properties of the material.

ing to SANS specifications is conducted.

CMA in collaboration with the industry

Precast concrete is their exclusive

As an example, the standard require-

and sent to a SABS workgroup for re-

domain, so the auditing and testing

ment for the production of concrete

view. After circulation to the industry for

process is very focused, efficient and

r e t aining w all blo ck s

input and comment, revi-

quick, typically taking no more than

(CRB) SANS 508-2012

sion and fine-tuning, the

four to six weeks, provided no non-

is published in a 17-page

standard is approved by

conformities are identified.

do cumen t . Ma t er ials

the workgroup. It is then

which must meet speci-

typeset by the SABS in

Bringing stability

fied quality standards

SANS format and a proof

“Mor eover, because this is a CM A

in SA NS 508 include

is sent back to the work-

initiative, it’s designed as a service to

cemen t, aggr ega tes,

group for final revision.

the precast concrete industry. As such,

wa t er, pigmen t s and

Then, on behalf of the

it’s priced well below the going rate,

colouring. Dimensions

Department of Trade &

a factor which makes it accessible to

and nominal dimensions,

Industry – the curator

both the small and large producer,” adds

shape, compr essi v e

Cockcroft.

strength, slump, dry-

(Above): Henry Cockcroft of the CMA.

of all SANS standards – the document is

“We’ve already audited 14 precast

cast specifications and mass, which

allocated a SANS specification number

concrete manufacturers and issued

should not be less than 95% of the nomi-

and is published as an official SANS

CM A C S cer ti f ica tes in compliance

nal mass, also form part of the standard

standard by SABS.

with South African National Standards

requirements, as do application testing

[SANS] since CMACS was first granted

and marketing.

Cockcroft believes that standards are the very bedrock of a well-ordered

SANAS approval in August 2017. It’s

In addition to the certification work

society. “Chaos would reign without

had a stabilising influence on the precast

undertaken by CMACS, the CMA sits

them, which is why it’s so important

concrete industry. Everyone’s benefited

on a workgroup within the SABS which

that precast concrete manufacturers

– the manufacturer, the professional who

ini tia tes new and r e v ises ex isting

have ready access to a reputable and

specifies the product and, of course, the

standards. The workgroup comprises

af fordable cer tification agency,” he

end user, in the knowledge that CMACS

SABS personnel and a broad group of

says. “Judging from the feedback we’ve

certification guarantees performance

professionals, all of whom are involved

received, it appears that CMACS has

across 16 precast concrete SANS

with precast concrete.

boosted conf idence in the pr ecast

specifications. “CMACS was appointed an accredited

concrete industry. Architects, engineers Averting chaos

and other specifiers now know that

certification body by SANAS in terms

When the precast concrete industry re-

ther e’s a r eliable means of r eadily

of Section 22 of the Accreditation for

quires a standard to be updated or a new

sourcing precast concrete products

Conformity, Assessment, Calibration

standard needs to be initiated, a written

with officially sanctioned certification.”

PRECAST | ISSUE ONE | 2019


ICRI AWARD OF EXCELLENCE On 9 November 2018, for the first time in 21 years, a South African company won the Award of Excellence at the International Concrete Repair Institute (ICRI) Awards, which took place in Omaha, Nebraska, USA. The award was presented to Sanika Waterproofing Specialists (a CMA non-producer member) for its professional concrete repair and waterproofing of the Anglo-American coal mine ventilation shaft at Goedehoop Colliery in Mpumalanga. The ICRI is an industry body consisting of world-renowned engineers, architects, manufacturers and contractors who host an annual awards ceremony to honour outstanding projects in the concrete repair industry, with over 50 project entries per year. This was a huge boost for the local concrete repair and rejuvenation market, as it revealed South African companies to be a formidable force in the international concrete repair industry. Approximately 7 000 litres of water were flooding into the shaft per minute through numerous cracks up to 300mm wide, creating a significant safety hazard and possible failure of the structure. An immediate and permanent solution had to be found to remedy this massive ingress of water. Numerous products were tried, but were unable to resist the enormous extent of water pressure which forced itself across the 9m diameter shaft. Not many products or applications in the market are able to be applied on the negative side against such pressures. Sanika’s professional expertise, combined with Kryton’s concrete waterproofing repair and rejuvenation products, successfully waterproofed the cracks and stopped the flooding. Furthermore, the structural integrity of the shaft was maintained, thus improving durability. The crystalline technology penetrates crystal growth deep into the concrete mass, transforming the concrete itself into a waterproof barrier and resulting in a dry, safe and usable shaft. Kryton crystalline technology can withstand 14 bars (140m) of negative pressure, self-heals cracks up to 0,5mm and drastically decreases water permeability of the concrete. (Top): Brian MacNeil, ICRI’s regional manager: North America, presents director Paul Smit and technical sales director Colte Smit, both of Sanika Waterproofing Specialists, with the Award of Excellence.

PRECAST | ISSUE ONE | 2019


INDUSTRY NEWS 8

TRAINING COURSE TO RAISE PROFESSIONALS ABOVE THE PACK Construction industry professionals need

(Above and left): Concrete at its best.

only devote five days of their time for

(Below): John Roxburgh, senior lecturer at The Concrete Institute’s School of Concrete Technology.

intensive training in concrete technology to boost their own career opportunities

certification, professionals will command

and ensure that the structures they

respect in the construction industry and

design have the sustainability the South

be able to access wide-ranging, career-

African economy vitally requires.

boosting opportunities.

This is the view of John Roxburgh, senior

“Every construction company, cement

lecturer at The Concrete Institute’s

SCT30 Concrete Technology should be

producer, admixture supplier, ready-

School of Concrete Technology, who

their priority. The five-day course with

mixed concrete company, concrete

believes there is an alarming dearth of

laboratory sessions covers important

testing laboratory, precast concrete

civil engineers with sufficient knowledge

aspects such as:

factory, structural consulting firm,

of how concrete really works.

• Properties of concrete in fresh, early,

municipality, government department

“C oncr e te technolog y sk ills ar e

and hardened stages.

dealing with infrastructural development,

extremely scarce in SA, mainly because

• Concrete mix design and production.

architectural and quantity surveying

too many professionals are either not

• Mix design for specialised applications.

business, pr oject development and

prepared to devote time to studying the

• Off-shutter and architectural finishes.

subject or feel that such knowledge is

• Formwork, reinforcement and joints.

not vital in their profession. But with

• Defects, blemishes and repairs.

increasing press reports of structures

• Mixing water and chemical admixtures.

collapsing prematurely all over the world,

• Temperature’s effects on concrete

it is time for consultants to realise

quality.

that they simply cannot do without a

• Placing, compac tion, pr o tec tion

technological knowledge of concrete,”

he says.

and curing. Roxburgh says professionals who

successfully complete the SCT30 training Priority learning

course can increase their concrete skills

Roxburgh declar es that if civil and

with more advanced training, culminating

structural engineers – and architects

in the globally respected Advanced

– have time for only one training course,

Concrete Technology (ACT) certification.

the School of Concrete Technology’s

However, even if armed only with a SCT30

“The education and competencies gained from this course will enable a budding concrete technologist to immediately make valuable contributions.” PRECAST | ISSUE ONE | 2019


technology – and the SCT30 Concrete

technology issues not only for his or her

of a person competent in concrete

Technology course is the launching pad

company, but for the national construc-

technology,” he says.

for such ambitious professionals.

tion industry as a whole.”

“It provides a strong foundation to Ambitious professionals

all important concrete concepts, along

• The minimum entrance requirement

“That list is actually far from exhaustive.

with delving into more advanced con-

for the course is a Grade 12 education.

There are also the exciting and many-

crete mix design, cold and hot weather

For full details about qualification for

faceted fields of decorative concrete

concreting, special mix types and deal-

SCT30, as well as other courses planned

now increasingly emerging to further

ing with heat in mass concrete. The

for Midrand, Cape Town and Durban

illustrate the huge scope for concrete

education and competencies gained

by The School of Concrete Technology

technologists. The scarcity of concrete

from this course will enable a budding

in 2019, tel: (011) 315-0300, e-mail:

technologists is good news for anyone

concrete technologist to immediately

sct@theconcreteinstitute.org.za or

wanting to make a career out of concrete

make valuable contributions to concrete

visit: www.theconcreteinstitute.org.za.

FINDING ECONOMICAL USES FOR COAL ASH Mountains of ash from our coal-burning power stations can be avoided if new

About SACAA

uses can be found to convert it from

SACAA is the umbrella association

waste product to a valuable commodity.

for the producers, marketers,

Already some of the ash is making its

user s, uni v er si ti e s, r e se ar ch

way into the country’s cement products

organisations and individuals playing

to lend str ength and aid curing of

an active role in the promotion of

concrete, as well as having applications

responsible ash utilisation.

in agriculture, ground stabilisation and

Its purpose is to grow the indus-

other uses. But the combined offtake of

try for the development of its mem-

these is below 7% of the ash produced

bers and the benefit of the South

and needs to be boosted considerably

African economy, in compliance with

higher to 18%, if environmental goals are to be met.

the environmental legislation. (Above): Mark Hunter of SACAA.

SACAA is associated to most

For some time now, the SA Coal Ash

as uses in manufacturing, chemical in-

of the world’s Ash Associations

Association (SACAA) has been working

dustries, landscaping and other uses. We

and has had representation at

with government, environmental agencies

need only look at the amazing composition

World Ash Conferences, including

and business to develop solutions to

and structure of different types of ash

the presenting of papers, training

growing ash dumps. Simultaneously, the

produced in each power station, from fine

courses and poster stands.

aim is to alleviate other socio-economic

and potentially valuable fly-ash to coarse

issues affecting the population which, if

bottom ash and everything in between.

successful, can have positive and far-

For further information, contact Mark Hunter on tel: 083 631 0793,

“We simply need to challenge our

e-mail: mehunter22@icloud.com or

technical brains trust to look for applica-

visit: www.coalash.co.za. To con-

tions in their fields of work or study and

tact Aspasa, tel: (011) 791-3327

Take the challenge

to find ways of overcoming problems to

or e-mail: office@aspasa.co.za.

During a recent fact-finding tour of the

integrate ash into their supply chains.

Matimba and new Medupi power station,

And, for those who think this is an im-

SACAA general manager Mark Hunter

possible challenge, it’s worth noting that

revealed that research is underway to

certain countries in developed economies

This proves its worth and shows that

determine the viability of treating the

are using as much as 80% of their ash

with a little willpower and innovation,

scourge of acid mine drainage throughout

produced,” said Hunter.

SA’s powerful business and technical

reaching benefits.

the gold mining areas known as the Reef

superb Maputo Bridge in Mozambique.

sectors have the ability to solve the

with suitable coal ash. Certain building

Valuable elsewhere

growing ash dilemma, while at the same

products made with ash are also being

South African fly-ash and ash products

time using the free resource to over-

tested and reviewed for suitability to

were selected to enhance concrete used

come some of the biggest challenges of

alleviate housing shortages.

to build the world’s then tallest building,

the current generation.

“However, these aren’t new ideas and

the Burj Khalifa, as well as improving

SACAA recently joined forces with

we believe that a myriad of other uses

concrete used to construct the Katse

the large surface mining industry as-

exists for this waste product. There are

Dam, the highest, deepest and one of

sociation, Aspasa, to improve its reach

certainly more uses in civil engineering for

the largest water storage dams in the

to a similar and broader cross-section

roads, concrete structures, etc, as well

country, as well as the architecturally

of industries.

PRECAST | ISSUE ONE | 2019

INDUSTRY NEWS

management firm needs the services

9


INDUSTRY NEWS 10

OBITUARY: JOHN SIMPSON John Simpson died after a sustained ill-

Early days

was not very often. During the 1990s he

ness. He is survived by his wife Penny, his

John joined Anglovaal’s construction

assisted Grinaker Masonry through some

daughter Diane and his son, Bruce. A sec-

arm, Grinaker, as a financial manager in

difficult economic conditions and tight

ond son, Michael, tragically predeceased

1984, working for the supplies and ser-

budget constraints and, thanks to his

John in a motor car accident in 2012.

vices division. Comprising nine companies

input and guidance, the company emerged

John was born in Klerksdorp and, at

(Grinaker Pr ecast and

from that period with a

the age of 11, was sent to boarding school

Grinaker Duraset among

healthy balance sheet.

at St Andrew’s in Bloemfontein, where he

them), it also included a

While still with Gri-

matriculated in 1958. The following year

battery factory in Zimbab-

naker, John joined the

he enrolled for a CIS at Unisa. During his

we and a piling company.

CMA’s management com-

part-time studies, he worked as an arti-

He was promoted to Gri-

mittee in 2000 to run the

cled clerk for Whiteley Bros in Klerksdorp.

naker’s financial services

financial portfolio. In addi-

John and Penny were married in 1965

division in 1992 and a

tion, he participated in the

and in 1967 moved to Benoni, where they

year later, was appointed

association’s strategic

raised their children and established

as its finance director, a

planning and gave valuable

strong ties with the local community.

position he retained until

input regarding its direc-

He joined Anglovaal’s Hartebeesfontein

his retirement in 2003.

tion and development. He

Gold Mine as an accountant in 1966

B e side s b eing ex-

was also instrumental in

and, the following year, was transferred

tr emel y conscien tious

guiding the association’s

to its head office, where he worked for

– he was an early bird

transformation from be-

several Anglovaal subsidiaries, including

and always in the office

ing heavily dependent on

National Bolts. His professionalism and

no later than 7am – John

diligence did not go unnoticed and it was

was gregarious and outgoing. He got on

being largely self-financed, and it was

not long before he was given additional

well with everybody, but was also known

during this period that he was appointed

responsibilities.

to be tough when he needed to be, which

financial director.

the cement producers to


DID YOU KNOW

Sports-lover John had an enquiring mind and many extramural interests. A keen sportsman, he was a provincial water-skier for Western Transvaal. He played hockey for Western Transvaal/Griqualand West

IS AVAILABLE

and continued playing social hockey until he turned 50. He also loved outdoor activities, including gardening and bird-

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ing. He was knowledgeable about the bush and wildlife and, on one occasion, he walked with a herd of elephants for several hours, often being close enough to touch them. He was introduced to fishing – which developed into a passion – by his col-

ISSU

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016

league and good friend John Siebert, 0

R49.0

when they hired a houseboat on Lake Kariba in 1990. John returned the compliment by acquainting JS with the

THE

beneficial properties of whisky. Some

CMA

years later, the two Johns and their

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• 2018

A– E CM

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wives spent a week in Scotland, where

ISSU

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they visited distilleries and developed a

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deeper understanding and appreciation of the noble spirit. Locally, John was a member of the Whisky Fraternity, an association comprising a dozen or

THE

so professionals who met on the last Thursday of every month to engage in lively conversation and sample some

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single malts and lesser-known whiskies.

• CM A • Cre CS und erta atin kes g sa • Se first fer awa work aud ll pro its plac tects es Stra nd

MA –

John was also a member of Alicats,

THE C

ST IN

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an inf ormal trout-f ishing syndicate

which meets at a fishing resort near Dullstroom several times a year. The 12-member group also assembles every Friday for conversation and light refreshment in Johannesburg. Helping hand Last, but not least, John gave very generously of his time and professional expertise to the underprivileged and

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ls g wal tainin s en re cost wer • Gre rpiece rs lo aste rato ral m tu • Vib itec arch n A •

•W orld beat • 3D ing bl prin ock ted mak • Exc house er ellen ce on disp lay

those in need. He was heavily involved with Paradigm Shift in community work which included counselling, mentoring and helping young entrepreneurs find

rs winne nges Award challe • CMA omic ctures g econ or stru • Easin convey of n utio • Evol

their feet. John is fondly remembered by the CMA and its members. He resigned from the association in 2017 and from then until he passed on, he spent much

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of his time mentoring small businesses and enjoying visits to his bushveld cottage next to the Kruger National Park. Precast and the CMA extend our condolences to Penny and the family on their sad loss.

PRECAST | ISSUE ONE | 2019

CONTACT LINDA MEYER ON MOBILE: 083 626 8814 OR EMAIL: LINDA.PRECAST@GMAIL.COM

CMA

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S


A strong foundation for infrastructure success

NEW PALLETS FOR BRICK MANUFACTURER Cape Brick decided to invest in new production pallets from CMA member PMSA, the official dealer for myWood in SA. U p o n i n v e s t i g a t i o n, t h e supplier r ecommended that they test the new generation of UPadvanced pallets from my Wood. Cape Brick did so and, af ter thorough testing, was satisfied that the pallets’ high flexural strength, durable surface and good performance in a steam-curing system made them most suitable f or its manufacturing requirements. T he UPadvanced pallet is made with a wooden core and a plastic overlay. myWood started the development of this new product in 2014 and was able to get the patent for it in 2015. It was tested for more than three years by European customers of the company before starting sales in 2018. Specially developed “We put all our know-how of more than 30 years of production into this board,” says myWood sales manager Tobias Schmidt. “Using wood with mainly standing annual rings gives more stability to the board. By drying the wood to below 20% humidity, we can reduce the weight of the board and the deflection characteristics. “The elasticity modulus is 12 700N/mm2, which is better than most pallet types available on the market. The plastic covering ensures that the bottom of the bricks is smooth and flat, also enabling customers to produce large-dimension, high-quality products.” Anthony Gracie from Cape Brick is happy with the new myWood UPadvanced pallets. “We were looking for a high-quality pallet at a reasonable price,” he says. “The myWood boards combine the advantages of both plastic and wood. The wooden core makes the board solid and stiff and gives excellent vibration. The plastic covering prevents water from going into the board and gives a nice bottom surface finish to our bricks. By using the new UPadvanced production boards, we’ve succeeded in significantly reducing cycle times.” Cape Brick decided to purchase the UPadvanced with stainless steel C-profiles on the edges of the board and having 45° angles cut

ROCLA is South Africa’s leading manufacturer of pre-cast concrete products. Surpassing 100 years of product excellence, including pipes, culverts, manholes, poles, retaining walls, roadside furniture, sanitation and other related products within infrastructure development and related industries.

on the corners. myWood is offering the pallets in basically all common sizes up to 3m length. (Above): Tobias Schmidt of myWood with Anthony Gracie of Cape Brick and Gerrie Beukes of the PMSA.

About myWood myWood is the worldwide leading producer of wooden pallets. The company has about 270 employees and offers a variety of wooden products for the construction industry. The new UPadvanced is

Visit us on www.rocla.co.za for our nationwide branches

protected by German patent DE 20 2015 102 814. myWood has already been sold more than 50 000 of the new pallets.

PRECAST | ISSUE ONE | 2019


PRODUCTS 13

CONCRETE WITH CRACK-HEALING PROPERTIES

tionally accepted penetration depths are

Brouard says this test has frequently

tightness or impermeability of concrete.

been used in SA to evaluate the ef-

“The test method described in the

fectiveness of crystalline permeability-

European standard EN 12390-8 for

reducing admixtures. He cautions that

testing hardened concrete is arguably

these products do not waterproof con-

the most practical test method available

crete, but rather reduce the concrete’s

in SA,” he says.

An entire concrete structure can be transformed into an internationally

Up to standard

accepted watertight barrier with the

The standard stipulates the depth of

use of the crystalline permeability-

penetration of water under pressure

reducing admixture Chryso CWA 10,

to evaluate the watertightness of con-

from Chryso Southern Africa (a CMA

crete to liquid. A 50mm penetration

non-producer member).

depth is classified as being “imper-

This is according to Brenton Brouard,

meable with respect to potable water”

technical manager: concrete at Chryso

and a 30mm depth as being impermeable

Southern Africa, who says that interna-

w i th r e sp e c t t o w a t er c o n t aining aggressive substances. In some parts of the world, the 30mm depth applied to water containing aggressive sub(Top): An entire concrete structure can be transformed into an internationally accepted watertight barrier with the use of the crystalline permeability-reducing admixture Chryso CWA 10. (Left): Construction chemical specialist Chryso Southern Africa supplied its Chryso CWA 10 integral permeability-reducing admixture to the Temba Waterworks project.

PRECAST | ISSUE ONE | 2019

stances is lowered to 20mm.

used to describe the degree of water-


PRODUCTS 14

level of permeability and watertightness

Brouard highlights that watertight

“When used as recommended, it’s

to the internationally accepted levels;

concrete, also called impermeable con-

compatible with all Portland cements

some penetration of the liquid under

crete, is vital for any structure which

and their commonly associated SCMs,

pressure is still possible.

retains liquid under pressure. “The value

as well as most Chryso admixtures and

On the other hand, waterproofing

of the product is that it can reduce the

abe products,” adds Brouard. “In ad-

of concrete eliminates any penetration

ingress of liquid under pressure to inter-

dition, it doesn’t adversely affect the

of water into the concrete. This is ef-

nationally accepted levels. The concrete

slump, strength, air entrainment or

fected using various 100% waterproof

becomes a watertight barrier, with

workability of the concrete.”

membranes, which are applied in the

lasting, integral permeability-reducing

form of surface coatings of various

properties,” he stresses.

thicknesses. Whether it is positive or

The admixture is non-toxic and can be

negative permeability that needs to be

added to concrete at the time of batch-

reduced, this versatile admixture is ideal

ing, so there are no climatic restraints.

for concrete exposed to harsh condi-

This makes it process-friendly, allowing

tions. By reducing the permeability of

flexibility in construction scheduling.

(Below, from top): The total concrete work on the Temba Water Treatment Works project was 17 000m³, of which 14 000m³ contained Chryso CWA 10 in the mix; the Temba Water Treatment Works site is situated within the northernmost portion of the City of Tshwane Metropolitan Municipality. The Phase 5 extension of the waterworks site comprised the addition of a 30Ml/day module to the existing four phases.

concrete, Chryso CWA 10 protects it against chemicals, chlorides, seawater and corrosive groundwater. Crack repair The permeability of a concrete is directly linked to the continuity of its capillary network. The greater the levels of watertightness effected in concrete using Chryso CWA 10, the greater the level of discontinuity induced in the capillary network. This is because its active ingredients react in the presence of moisture, forming a dendritic crystalline structure throughout the entire concrete’s pore or capillary network. This means less chance of carbonation, alkali-aggregate reaction or corrosion of the concrete and its reinforcing steel. Being protected in this way from waterborne, soluble salts enhances the durability of the concrete and the structure itself. “Given the right conditions, it can even seal hairline cracks up to 0,4mm wide in the concrete,” says Brouard. “This is because its active ingredients react in the presence of moisture.” He adds that, in the absence of moisture, it will lie dormant. However, it will reactivate as soon as it encounters moisture. As long as moisture is present, crystals continue to grow within the concrete. Watertight barrier The dendritic crystalline formations take place within the existing crystalline structure of the concrete, so it is an integral system with no risk of debonding. The reduced permeability, as well as the corresponding improvement in chemicalresistant properties that can be affected by Chryso CWA 10, will remain even if the concrete surface has been damaged.

“Given the right conditions, it can even seal hairline cracks up to 0,4mm wide.” PRECAST | ISSUE ONE | 2019


NEW DESIGN SOFTWARE MAKES CRB WALL CONSTRUCTION EASIER CMA member Terraforce has launched

(inclination) and wall width into account,”

a new software package, Maxiwall Pro,

says Terraforce MD Holger Rust.

for the design of concrete retaining block

Once a design is completed, Maxiwall

(CRB) walls. The software is a privately

Pr o also allows the ex por t o f wall

labelled version of the world’s most

geometries, soil and loading conditions

comprehensive and widely used CRB

to specific global stability sof tware

design software – the Vespa Mechanical

programs.

Stabilised Earth (MSE) design suite.

Rust cautions, however, that Maxiwall

Maxiwall Pro allows designers to

Pro is a professional analysis tool and

easily produce complete wall designs

should only be operated by designers

using Terraforce’s award-winning line of

and engineers well versed in CRB design.

CRB products. With all block and geogrid

“We’ve provided simple, easy-to-follow

information pre-loaded, designers can

design tutorials with Maxiwall Pro. These

select from a wide range of proven

cover the generic version of Vespa MSE

Terraforce systems from easily navigable

design software, but generally apply to

drop-down menus.

Terraforce CRB wall design.

Maxiwall Pro increases design efficiency, improves accuracy and promotes

Free software

a seamless flow of information between

“Our first design software, Maxiforce

design stages and parties. It generates

2000, was launched in 2004, followed

full wall layouts with accurate quantity

closely by Terrasafe, a retaining wall

estimates and comprehensive reports.

design service that provided first-class

In addition, its calculation engine can

engineering, management and specialist

simultaneously run static, seismic and

technical assistance to users of any of

internal compound stability analysis in

the Terraforce products.

accordance with NCMA, AASHTO (LRFD),

“Many complementary publications

Australian Standard, British Standard

per taining to block speci f ica tions,

and local design methodologies.

sustainability, plantability and irrigation, together with at least 250 project

Professional tool

profiles, have been made available by

CAD cross-sections and elevation views

Terraforce over the years,” says Rust.

are automatically generated and ready for import into AutoCAD using a Drawing

Maxiwall Pro is available at no charge to CRB design engineers.

Interchange Format output feature. Users also have the option of buying a copy of the AWall CAD tool, which allows them to accurately present plans and elevation views on grading plans. “AWall can create elevations and generate quantities in a ‘real’ wall footprint and takes variable wall height, wall batter

PRECAST | ISSUE ONE | 2019

“AWall can create elevations and generate quantities in a ‘real’ wall footprint.”


COMPANY NEWS

(Right): The success of this initiative is one to which all AfriSam employees proudly contribute as they take Caleon Garden Creations pupils under their wing.

More pupils at The Gateway School for special education needs in Roodepoort, Johannesburg, were recently empowered

16

in the art of concrete creations. Through a structured mentorship pr ogramme under taken by pr ecast concrete manufacturer Caleon Garden Creations, pupils are being given the opportunity to create their own art using concrete. A range of other skills is also being imparted during the initiative, creating concrete possibilities for pupils as they prepare to graduate. The Gateway School’s focus is helping children with special needs realise their full potential by providing excellent educational opportunities and developing each pupil holistically. This includes empowering them with the skills and knowledge they need in the world of work. In doing so, the school of ten collaborates with corporates to expose the youngsters to various skills and has partnered with Caleon Garden Creations for the past four years. Outdoor furniture pleasure to impart skills that these

range of concrete products such as

GATEWAY SCHOOL PUPILS LEARN THE ART OF CONCRETE

tables, benches, pots and water features.

part to make this initiative succeed.”

there were people who understood its

AfriSam recently came on board to support Caleon Garden Creations in this worthy cause. In the programme, batches of three or four pupils at a time are placed under the wing of the company’s management and employees. With a factory in Rietfontein, Caleon Garden Creations manufactures a wide

Its products epitomise creativity and artistry in the use of concrete.

Upon completion of their practical block, a recent batch of pupils were

pupils can use. Hopefully, we’ve inspired them to build on those skills and create their own businesses in the future. With each group who joins us, we’re inspired anew by the commitment from the school.” The school’s occupational therapist, Karen Botha, said it was touched that pupils’ needs and were committed to helping this cause.

For AfriSam, with its commitment to

excited to show of f their creations

“Our continued par tnership with

community upliftment and empowerment,

and exuded confidence in working with

Caleon Garden Creations and now with

this initiative represents a fitting cause.

concr e te. I t was a pr oud momen t

AfriSam gives our pupils opportunities

The company’s own efforts are focused

for all involved as they witnessed the

t o l e a r n n e w s k i l l s,” s a i d B o t h a .

on projects that are sustainable and

achievements of these youngsters and

“More importantly, it helps them build

enable the beneficiaries to become self-

their enthusiasm in showcasing their art.

confidence in their abilities and shows

Speaking at the event, Caleon Garden

them how much more they’re capable

sufficient.

Creations owner Ferdi de Wit said the Teaching skills

initiative was the company’s way of

“We’re very excited to be a part of this

contributing to the upliftment of society.

initiative and are inspired to see the work Caleon Garden Creations has been doing

Kind tradition

with The Gateway School,” says Adele

“For my team and me, working with

Wentzel, sales manager for AfriSam.

The Gateway School is a heartwarming

“Going forward, we’d like to continue in

tradition that we’re proud to carry

this partnership and ensure we do our

through,” said De Wit. “It’s our greatest

of. For that, we’re grateful.”

“Pupils are being given the opportunity to create their own art using concrete.” PRECAST | ISSUE ONE | 2019


COMPANY NEWS

(Right): Adrien Desmarais of Progressive Paving, Revelstone founder and director Andrew Cyprianos, Mike Reynolds of Cape Flora Landscaping and Revelstone managing director Alex Cyprianos at the launch of Revelstone’s new showroom.

17

REVELSTONE LAUNCHES NEW SHOWROOM AND CELEBRATES 25TH YEAR CMA producer member Revelstone, one

Revelstone was founded by Andrew

of the country’s leading manufacturers

Cyprianos in 1993 and initially operated

of cast-stone products, celebrated its

from an underground cellar in Muizenberg.

25th year by launching a new showroom

Its reputation for product development,

in Lansdowne, Cape Town.

innovation and quality personalised

Designed as a landscaping idea hub

service spread rapidly, catapulting the

for architects, landscapers, interior

company to the pre-eminent position it

designers, building contractors and home-

commands today.

owners, the showroom is a visual feast,

Cast-stone products are durable,

showcasing a wide range of Revelstone

recyclable, cost-ef fective, versatile,

paving, cladding and coping for both

energy-efficient and innovative.

outdoor landscaping and various indoor

“Natural stone products are becom-

applications. In addition to a double-

ing more expensive and less environmen-

volume exhibition space, the showroom

tally friendly, and are generally imported,”

boasts a boardroom for meetings and

said Cyprianos. “By contrast, our prod-

demonstrations on a large screen, an

ucts are produced using 95% local raw

outdoor garden area and a coffee bar.

materials located within 100km from our

Speaking at the launch on 13 September, Revelstone managing director

factory. In addition, all our moulds are 100% recyclable.

Alex Cyprianos said the facility is a forum

“Our pr oduc ts ar e almost in-

aimed at inspiring design creativity in the

distinguishable from natural stone and

built environment.

w e u s e t r a d i t i o n a l m a s o n r y sk i l l s

“We’re encouraging all our clients, be

combined with a modern moulding tech-

they home-owners or landscape architects,

nique to painstakingly reproduce an

to use this space to meet and collaborate

original master, which is then used to

in a relaxed atmosphere,” he added.

create a mould.”

PRECAST | ISSUE ONE | 2019


WEAR DEVELOPMENT Moulds are among the most important parts of the concrete manufacturing process as they play a direct role in the overall costs and quality of products produced.

regular maintenance, however, these

abrasive material contributes more to

defects are only found in exceptional

wear than finer-grained aggregates.

cases in most concrete block plants. Upper-edge wear Wear at the upper edge of the mould occurs much more frequently and can similarly be attributed to various causes.

Good moulds produce good products and

A central aspect here is the centering

bad moulds do not. That is the long and

of the mould in the machine. There is

the short of it, according to Chris Hense

no system on the machine side that

of specialist mould manufacturer Kobra

can optimally align the mould and keep

Moulds in the Netherlands. High-quality

it in this position during the production

moulds produce economical and well-

process. Kobra moulds have a gap of

made products that fetch higher prices

four-10ths of a millimetre on all sides

on the market than poorly-made ones. It is essential to use the best-quality

Figure 1: Checking for wear at the lower edge of the mould

moulds possible to ensure the overall quality of products and thus ensure the efficiency and profitability of a plant.

between tamper shoe and stone cavity in order to ensure the smooth plunging of the tamper head into the mould cavities.

Increased wear at the lower edge

However, in order to keep the mould

of the mould can also occur if the

c en tr e d dur ing the manu f ac tur ing

As one of the world’s leading mould

relation between the vibration power

pr ocess, ther e is a distance of at

pr o duc er s, K obr a F or men GmbH

and frequency settings is not balanced in

least 1mm on all sides in the machine,

offers not only the development and

the machine (ie not adjusted to suit the

depending on the make – larger than

manufacture of concrete block moulds,

respective product) and the vibration is

the gap between tamper shoe and

but also their maintenance and repair.

too strong.

stone cavity. The result can be one-

Kobra has compiled a list of typical signs

“Since consistent centering cannot be guaranteed on the part of the machine, this type of wearing should be checked on a regular basis.”

sided loading of the mould, since the

of wear and their causes. “ T he c oncr e t e blo ck mould is a precision tool that combines numerous functions for the manufacture of highquality products,” says Hense. “However, even the best moulds are subject to wear and this may lower the value of end-products if the tool wears to the point where it becomes defective.” He therefore advises manufacturers to look for the following signs of wear:

lateral forces will move the mould and the tamper shoes will therefore make contact with the tops of the cavity walls each time they plunge into the mould during the compaction process. Since consistent centering cannot be guaranteed on the part of the machine, this type of wearing should be checked on a regular basis. One way to reduce such wear is by periodically replacing the plastic strips that assist in keeping the mould bottom centred in the machine.

Lower-edge wear

A further interaction exists between

The experience of Kobra service

the vibration power and the mould

Mould surplus

engineers shows that wear at the lower

contact pressure. This should not be set

One of the internationally observable

edge of the mould only occurs very rarely

too low or the mould will lift up from the

trends in the concrete block manufac-

today. The causes of such wear could be

board and material will flow out. In this

turing process is production with a small

mechanical (ie in the machine itself) or

scenario, the concrete runs underneath

mould surplus. According to Kobra, the

due to various incorrect settings.

the mould, which can wear enormously.

normal mould surplus standard can be

Mechanically related wear can occur,

If, on the other hand, the mould contact

explained by the following example:

due to damaged rubber buffers on the

pressure is too high, the mould will be

A concrete block is to have a height

vibrating table or broken bearings on the

overloaded and the vibration power of the

of 80mm and a shoe chamfer and insert

mould clamps. Cracks in the vibrating

machine absorbed. Therefore a product-

chamfer of 4mm each. The mould height is

table, the machine frame or defective

related co-ordination of vibration power

92mm. Therefore, due to the difference

production boards can also contribute

and contact pressure is necessary.

between the block and mould heights,

to higher wear, since the mould is

Ultimately, the type of materials used

there is an insert depth of 12mm around,

subjected to greater stress. Thanks to

also plays a decisive role. Strongly

which can adequately dissipate the

PRECAST | ISSUE ONE | 2019

GLOBAL VIEW

PRODUCTION TRENDS AND

19


GLOBAL VIEW

forces created from the tamper head to the mould during main compaction. If the block height (including the chamfer and insert chamfer) is the same, but the mould height is now only 88mm, the insert depth is only 8mm high around during main compaction. Wear is

20

increased because less area is available to dissipate the forces.

Figure 4: Heavy wear at the upper edge of the mould

Figure 2: Mould with normal mould surplus

Figure 3: Mould with low mould surplus

upper side of the mould because the

based compulsory centering known as

damage is only minor, then the tamper

Headguide™, which has been successfully

shoes must be separately adapted to the

used for years. Headguide guarantees a

changed dimensions of the stone cavi-

play of two-10ths of a millimetre around so

ties. The tamper shoes are aligned at the

that the tamper shoes and stone cavities

narrowest point in the mould cavity, with

cannot touch each other.

the aforementioned gap of four-10ths of

Thanks to the special design of the

a millimetre around. This results in a sig-

centering bushing, the mould can move

nificantly larger tamper shoe play in the

more freely, compared with solutions

worn areas of the stone cavities, which in

from other manufacturers, but is at the

turn can lead to sharp protruding edges on

same time consistently guided. The wear

the block. The possible replacement of the

of tamper shoes and the upper edge of

tamper shoes by trained technical person-

the mould is greatly minimised, since the

nel should be considered in order to ensure

guide bolts of the compulsory centering

constant quality of the concrete blocks.

ensure precise plunging of the tamper

If the production settings provide

Many of the listed causes of wear

head into the mould cavities. In addition,

for over-filling of the mould, the tamper

in concrete block moulds, which are

metallic abrasion and the so-called

shoes “swim” on the concrete before

precision tools, can be attributed to the

“bloom” formation are avoided.

plunging into the stone cavities when

poor and impermanent centering of the

Nevertheless, regular checking and

the tamper head is lowered during the

mould in the machine; however, this is

correction of the machine settings

compaction process. Characteristic in

important for a high-quality end product.

are important, since Headguide cannot

this case is one-sided wear at the upper

As a result, Kobra developed the mould-

correct improper machine settings.

edge of the mould during main compaction, if the aforementioned centering of the mould in the machine is not ensured. The tamper shoes strike against the stone cavities and damage the chamfers. At this moment, there is no centering or guiding between mould and tamper head. As a result, the wear at the upper edge of the mould may be too much for a repair to be viable. If the wear is as bad (as shown in Fig 5), there is no possibility of performing a repair weld on the upper edge of the mould, since the heat-affected zone around the welding seam is too high and the hardness necessary for long-term production is lost. A repair, which can be very complex and therefore highly expensive, is only of short-term benefit, since heavy wear typically occurs next to the welding seam. In addition, the stresses induced by the heat input during welding can result in an increased risk of cracking. If no repairs are carried out to the

Figure 5: The Kobra Headguide™ forced centering device

PRECAST | ISSUE ONE | 2019


from the material structure by heating.

application of the hardness grades

Economical and sustainable work in the

Through sudden cooling (quenching), the

most suitable for a particular concrete

manufacture of a product is only possible

elements are prevented from remixing.

b l o c k m o u l d, c o m p r e h e n s i v e h i g h

with suitable machines and tools. In the

At this point in the process, the steel is

wear-resistance can be achieved with

production of concrete products using

certainly very hard, but also extremely

significantly extended mould stability.

vibration technology, the mould is subject

brittle, so further processing for mould

to high mechanical stress. A durable tool

construction would be impossible.

is essential for mass production and the demand for the greatest possible wearresistance in the concrete block mould is therefore understandable. The mechanical stress on the mould tool can certainly be reduced by the correct machine settings, but not prevented. Therefore the wear-resistance of the steel material must be increased. Kobra has developed hardening processes matched to the particular mould type.

“The mechanical stress on the mould tool can certainly be reduced by the correct machine settings, but not prevented.”

The basis is different heat treatments

In addition, Kobra has developed a

GLOBAL VIEW

Increasing wear-resistance

system in which all feedback concerning the use of the mould is recorded, enabling conclusions to be drawn regarding possible improvements. Engineers, designers, production technicians and sales employees work closely together in order to offer the customer the best possible service in the after-sales phase and to minimise damage-related production losses. Kobra aims to form partnerships with its customers and offers much more than the manufacture of a tool. Support and transfer of knowledge,

of the material which alter its structure

Record-keeping

from the development and manufacture

by means of a tested temperature-time

The required material properties are

of a concrete block mould up to its

progression that produces the desired

therefore only established in the next

use, ar e principal r equir ements o f

hardness properties.

step of tempering. The steel has a

Kobra’s philosophy, which the company

Optimill Nitro® and Optimill Carbo-

harder surface and a depth of hardness

has successfully applied worldwide for

68Plus® are possible in Kobra’s in-house

that is suitable for use in the machine.

more than 25 years. Kobra produces all

hardening facilities. Basically, both pro-

The core has an optimal toughness for

possible types of moulds for all possible

cedures involve the separation of carbon

further processing. Thanks to standard

types of block machines.

21


TECHNICAL 22

The Civil Engineering Department of the University of Cape Town (UCT) has embarked on a research programme which aims to improve the performance of South African permeable paving in-

UCT RESEARCHES LOCAL

PERMEABLE PAVING PE

stallations. Locally introduced 10 years

or nature-based hydrological cycle.

ago, initial evidence suggests that perm-

“Unlike attenuation ponds, swales

eable paving is not meeting its objectives

or bio-cells, permeable paving doesn’t

of successfully retarding the short-

require additional space. This is why

circuiting of stormwater discharge, nor

it’s being widely used in Cape Town’s

the elimination of contaminants from

urban environment, where the City’s

stormwater run-off.

Management of Urban Stormwater

The research work is being spear-

Impacts Policy (2009) mandates the

headed by Neil Armitage, deputy-director

rate at which water can be released

of Future Water and a professor in

into stormwater infrastructure and

UCT’s Department of Civil Engineering.

the quality or purity of the water.

He is being assisted by a working group

Our data shows that none of Cape

comprised of professionals and some civil

Town’s installations – and, we assume,

engineering students.

permeable paving installations in other

“Our research effort is twin-pronged:

par ts of the country as well – are

gathering field data from permeable

functioning at any where near their

paving sites throughout the country,

current practice in SA is to simply copy

while simultaneously conducting

overseas design guides in the hope

optimal design parameters. “Blockage is the chief inhibitor of

laboratory experiments,” says Armitage.

that they work, without due regard to

permeable pav ing per f ormance and

“Our fieldwork focuses on the rate

differing environmental conditions. Our

all the systems we’ve tested exhibit

of stormwater infiltration, while our

prime objective is to devise a system

it, some more than others. Blocking

lab work deals with the removal of

or systems which work best under local

has several causes, including wind-

contaminants.

conditions and to then provide evidence-

blown sand (especially in Cape Town),

“As yet, there’s no national standard

based guidelines aimed at ensuring

vegetable matter, litter and cigarette

f o r t h e d e s i g n, c o n s t r u c t i o n a n d

much-improved systems which mimic, a

butts. It’s also caused by an internal

maintenance of permeable paving. The

closely as possible, the pre-development

build-up of sludge due to accumulated

PRECAST | ISSUE ONE | 2019


our team has been involved is right here on

(Left): Washing the aggregate in the UCT laboratory.

area which was constructed outside

(Below): The SWIFT test bucket.

the New Engineering Building [NEB] six

campus. It’s a permeable paving parking

years ago. Using the SWIFT method, a sand-infested bedding grit which was

Master’s student examined the water

then replaced with clean grit. Once this

infiltration capacity of 60 locations

operation had taken place, the paved

situated within 13 sections. Her tests

surface remained blocked. The removal

revealed five unblocked, two semi-blocked

of a few paving blocks then revealed that

and six fully blocked sections. The worst

some of the dirt had been blown into,

blocking took place on the perimeter of

rather than out of, the installation and

the parking area, which was subject to

was wedged between the pavers and the

the incursion of vegetable matter from

geotextile membrane,” explains Armitage.

the adjacent flower beds and trees.

“ W h a t d o e sn’t h e l p u s i s t h a t

Hardly surprisingly, the best or least

some countries have got away with no

blocked section was in the centre of the

maintenance for a long time. For example,

parking lot, furthest from the vegetation.

an installation over 20 years old in

“Given that it’s very hard to measure

Hamburg, Germany, has apparently never

the quality of water that passes through

been maintained and is still functioning,

a permeable paving system, we had

albeit only partially. However, the area in

three sumps built for water sampling

question is very large and is situated in a

dur ing c o n s t r u c t i o n o f t h e NE B’s

soggy regular rainfall environment, with no

parking lot. The first simply receives

wind-blown sand. And because permeable

contaminated r oo f r un-o f f without

paving has a design safety factor of 10

any filtration. The second is fed with

[ie 10 times anticipated run-on], one can

stormwater after infiltrating through a

theoretically have 90% blockage before

geotextile membrane and three layers

failure occurs. By contrast, most South

of aggregate. The layout for the last

African installations tend to be much

sump was the same as for the second,

smaller and, besides being subject to

except that we removed the geotextile.

wind-blown sand, are often situated close

In theory, the water in sumps two and

to vegetation and trees. This means that

three should be relatively clean. That’s

contaminants, especially in installations

a 90% blockage can occur in six months.

the theory, but the practice turned out

in which geofabric membrane has been

In fact, if landscaping soil is dumped on

to be somewhat different.

laid as a filtering mechanism below the

a permeable paving surface, a blockage

bedding course.

can occur instantly.

ERFORMANCE

“During construction of the NEB’s parking area, we replicated the test

“Unwashed aggregate is another

“There are various methods of test-

sections feeding through sumps two

cause for concern and is one of the

ing the infiltration rate of permeable

and three using exactly the same design

major reasons permeable paving systems

paving. We’ve found the international

and materials in the laborator y so

aren’t removing contaminants as they’re

and A merican standar d to be ver y

that we could run tests in a controlled

designed to do. In fact, our recent

onerous and slow. They involve sealing

environment. Then we built two further,

laboratory experiments have shown

the outside of a permeameter ring with

completely different designs.

tha t unwashed aggr ega te ac tuall y

a special putty and recording the time

“Our testing on all f our layouts

exacerbates water quality.

it takes for water to infiltrate. It’s

involved simulating Cape Town’s average

“Regular maintenance/cleaning is the

almost impossible to get it to function

annual rainfall of 20 storms of 5mm

only way of combating blocking. However,

properly because there are always gaps

and above. And although we used clean

very little is being done in SA, even

through which the water leaks.

tap water, what we got out was full of

though it’s stipulated in all the guidelines.

“Instead, we’re using a simpler test

contaminants. Even after several cycles,

Cleaning is complicated and, as yet,

– the SWIFT method, devised in Queens-

we only achieved marginal improvement.

there’s no fail-safe methodology. Various

land, Australia. It uses a wooden frame

Then we started doing projections and

systems are employed such as sweeping,

and a bucket which releases six litres

regression analysis to work out how

vacuuming, blowing with compressed air

of water through a 14mm hole onto the

long it would take before the water was

and spraying with water, all with limited

paved surface. It’s a very quick test and

squeaky-clean. Our projections indicated

degrees of success, or no success at all.

uses much less water than the American

that this could take well over 10 years.

“For instance, we recently witnessed

one. It works on the basis of water im-

In the end, we got tired of the process

a cleaning operation at Steen Villa, a

print on the paved surface. The smaller

and told the student to flood and flush

residential complex in Cape Town, where

the imprint, the better the infiltration

out test samples. He did that and things

compressed air was used to remove

rate and vice versa,” says Armitage.

started to improve.

PRECAST | ISSUE ONE | 2019

TECHNICAL

“One of the field test sites with which

(Far left): Prof Neil Armitage and civil engineering and permeable paving research student Kimberly Liu pose next to the 10 experimental permeable paving cells at UCT’s civil engineering laboratory.

23


TECHNICAL 24

“Then we stripped all four installa-

free. It was only after we’d brushed all

systems for North Carolina’s government.

tions and found a thick sludge layer at

the surfaces that the aggregate was

When I returned, we began experimenting

the bottom of each base course, which

clean. Thereafter, when we poured in clean

with some of the things he was doing.

was clearly going to be there forever.

water, we got out clean water. We then

For example, not using geotextiles and,

That’s when we became aware that the

reconstructed our test bins using prop-

instead, using sumps at the bottom of

aggregate wasn’t clean, even though the

erly cleaned aggregate,” says Armitage.

permeable paving installations to create

suppliers claimed it had been washed. We

“At that stage, I visited Prof Bill

aerobic zones – the theory being that

tried different cleaning methods using

Hunt of the USA’s North Carolina State

one can’t stop the ingress of dirt, so one

water hoses, but after letting it dry for

University, who’s conducting research

should rather let it settle at the bottom

two days, it still wasn’t contaminant-

into low-impact sustainable drainage

and take out the treated water from there. This is in contrast to the British AQUApave® system, which treats the water just under the bedding course. Of course, there are downsides to both systems. One gets blocked geotextile at the top and the other needs a storage facility, which uses more stone. “The quality of stormwater and level of contaminants varies greatly. But it would appear that nitrates and phosphates are the major culprits, because they’re widely used in garden fertilisers. One of our research students identified a commercially available fertiliser with a ratio of nitrates to phosphates which allows us to dilute it to the typical concentrations one finds in stormwater. T hat’s now our proxy for mimicking polluted stormwater.

(Above): The NEB parking lot blocked up with tree foliage and wind-blown soil.

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than to our conditions, which are hot and

with some field experience: consultants,

dry. Hence the American idea of using

contractors, suppliers, etc who’r e

nutrient-enriched tap water, measuring

a sump seems more suitable for local

prepared to share information about

the difference in results with untreated

conditions because a permanent pool of

their particular installations and designs,

tap water in 10 experimental cells in our

water provides a much better chance of

even if it’s just anecdotal. The more

laboratory using the same rainfall and

creating a permanent bacteria culture

feedback we receive, the more likely we

contamination regimes. Three cells in-

to handle the incoming food load. Even if

are to find a pattern. We should then be

clude a geotextile and some have missing

it’s just ticking over, it’s ready – at least,

able to begin building a permeable paving

stone layers. Each uses a different type

that’s our current thinking – and we’re

design guideline based on experiences

of paving and stone support system. The

willing to try it as a more effective way

across SA,” says Armitage.

bottom of each layout is perforated so

of improving water quality.

that we can remove sampling material. “Unfortunately, we don’t have the lux-

“We’re also eager to try other ideas. I’m particularly interested in people

(Left): Water samples for testing. (Below): The unblocked middle section of the NEB parking lot.

ury of changing one parameter at a time. So, in trying to hone down very quickly

UCT calls for help with

which systems are and aren’t working,

permeable paving research

we’ve had to take a shotgun approach.

Neil Armitage, deputy-director of

“One of the areas we’re investigating

Future Water and a professor in

is what happens during dry periods – for

the Department of Civil Engineering

example, when the geotextile dries out

at the University of Cape Town, has

and bacterial activity ceases. When

initiated a working group comprised

it rains again, it has to re-seed, much

of professionals and civil engineering

like a septic tank does. It’s therefore

students to conduct research into

possible that the use of a geotextile is

how to improve the performance of

better suited to soggy British weather

permeable paving systems and the quality of stormwater in a South African context. Armitage is seeking data and feedback from anyone involved with permeable paving, either in the supply of materials or its design and installation aspects, as well as its maintenance and upkeep. He is particularly interested in people in the field – ie consultants, contractors and suppliers – who are willing to share some details about their particular installations. He can be reached on tel: (021) 650 2589 or, preferably, via email at: Neil.Armitage@uct.ac.za

Permeable paving seminars set for May

Town (27 May), Durban (29 May) and

cleaning mechanisms for permeable

Ryan Winston, an assistant professor

Bloemfontein (30 May). They will be

paving installations, is widely published

at the USA’s Ohio State University,

organised by UCT’s Prof Neil Armitage

in technical and academic journals,

will be staging seven seminars

and are being funded by the Water

and has lectured at numerous

based on his research in the design,

Resear ch Commission. Delegates

conferences, workshops and seminars

construction and maintenance of

qualif y for continuing professional

in the USA and internationally. He

permeable pavements in that country.

development points.

received his MS and PhD at North

The seminars are free and are aimed

Winston is an internationally

Carolina State University studying

at civil engineers, landscape archi-

recognised exper t on sustainable

under Dr Bill Hunt and also worked as a

tects, town planners, paving con-

solutions for urban water problems

research engineer for him, overseeing

tractors and permeable paving

a n d, b e s i d e s c o l l a b o r a t i n g w i t h

construction of and research into

material suppliers. They are being held

Armitage in SA, shares information

urban stormwater control measures.

in Johannesburg (21 May), Pretoria

with colleagues in Sweden, France and

For seminar reservations, e-mail

(22 May), Knysna (23 May), Cape

Australia. He has researched several

Kim Liu at: LXXBOD001@myuct.ac.za.

PRECAST | ISSUE ONE | 2019

TECHNICAL

“This means we can now repeat the typical Cape Town rainy season using

25


TECHNICAL 26

AIR-PURIFYING CONCRETE CAN REDUCE

ATMOSPHERIC POLLUTION The use of air-purifying concrete in both

ing the prospect of lining tunnels with

pavements and surrounding structures

air-purifying concrete tiles combined

can play a major role in the reduction of

with conventional lighting,” says Perrie.

atmospheric pollution in urban areas, says Bryan Perrie, MD of The Concrete

Slow process

Institute.

As far as carbon dioxide uptake by con-

Perrie says air pollution is a steadily

crete is concerned, the process is gener-

increasing problem in densely populated

ally very slow, but can be deleterious to

areas and towns, with the most signifi-

concrete in that it can promote the cor-

cant pollution caused by fine particulate

rosion of steel reinforcement. This is not a

matter, volatile organic compounds

problem for concrete pavements because:

(VOCs) and nitrous oxides.

• Jointed plain concrete is not rein-

“When nitrous oxides are present

forced and carbonation is therefore

concurrently with VOCs, they lead to

fect in the laboratory. In these tests,

ozone formation and amplify the impact

the conversion of nitrogen dioxide as

• In continuously reinforced concrete,

of the fine articulate matter. It’s impor-

the result of a single contact between

the reinforcement lies at a depth of

tant to limit traffic emis-

the air and the photo-

60mm or more, depending on the

sions as much as possible,

ca tal y tic ma ter ial was

design. “This is sufficient to ensure

primarily by limiting the

determined: reductions of

that the reinforcement zone remains

traffic and therefore the

30-95% were measured.

untouched by the carbonation front

emissions. This is where

Efficiency in real-life ap-

during the lifetime of a pavement,”

concrete pavements and

plications aren’t entirely

says Perrie.

concrete structures in

dependent on the efficiency

He adds that pavement concrete is of

the immediate vicinity of

of the photocatalytic ma-

an exceptionally high quality and dense,

the pavements can assist

terial itself, but also on the

with few pores. The carbonation depth –

in reducing the effect of

contact quantity of air and

which is proportional to the square root

contact time between the

of the duration of the exposure – is only

air and the surface, the

likely to be 5-10mm after a period of 40

effect by using titanium dioxide on the

light intensity, relative humidity and the

years. In addition, because of the supe-

pavement and/or the structure’s sur-

amount and type of pollution present in

rior quality of pavement concrete, its

face,” he explains.

the air,” Perrie explains.

uptake of carbon dioxide is limited. How-

Neutralising effect

Testing continues

the absorption of carbon dioxide from the

When exposed to ultra-violet light,

He says the use of photocatalytic mate-

atmosphere increases significantly when

titanium dioxide acts as a catalyst

rials in the surface layer of a twin-layer

the concrete is demolished or crushed.

converting harmful compounds such as

concrete pavement or in thin concrete

nitrogen monoxide and nitrogen dioxide

overlays were tested at the Porte de

Slow leaching

into nitrates. These nitrates settle on

Vanves in Paris. Two 300m sections of

“Research from the Nordic Innovation

the surface and are washed away by

a busy street used by 13 000 vehicles a

Centre has indicated that as much as

rainfall. The nitrogen dioxide – which can

day were repaved as follows:

57% of the carbon dioxide emitted due to

lead to ozone formation, acid rain and

• One section with conventional con-

the calcination process in the manufac-

the emissions. It’s possible

(Above): Bryan Perrie, MD of The Concrete Institute.

to achieve an air-purifying

not harmful.

ever, the concrete will still carbonate and

the formation of particulate matter – is captured from the air. Photocataly tic materials such as titanium dioxide can also capture harmful

crete paving. • Another section with an experimental

thin concrete overlay using cement

with a photocatalytic action.

ture of cement will be reabsorbed by the concrete over 100 years,” says Perrie. As far as hazardous leaching products are concerned, tests have shown that

organic compounds from the air by caus-

“Measurements of the air quality and

the leaching behaviour of pavement con-

ing it to dissociate. The titanium dioxide

the surface water run-off were carried

crete – including both pavement-quality

is added separately to the concrete

out over the course of a year. It was then

and lean concrete – is totally harmless

mix. Alternatively, specially formulated

found that nitrogen dioxide contamina-

to the environment. “In fact, the quanti-

cements can be used which contain nano-

tion was cut by about 20%. Research

ties of heavy metals leached out turned

particles of titanium dioxide.

also revealed that the photocatalytic

out to be lower than the quantities that

“Various research projects have

reaction took place in ordinary visible

occur naturally in the mineral water sold

demonstrated the photocatalytic ef-

light, not only in ultra-violet light, open-

in stores,” he adds.

PRECAST | ISSUE ONE | 2019


PROJECTS

Permeable paving has been used in combination with asphalt paving to extend the parking capacity at Checkers Langverwacht Plein, a shopping mall on Langverwacht Rd in Kuils River, Cape Town. Completed during November 2018, the new parking area was required to provide additional bays f or building

27

extensions to the mall. PermeaLock paving blocks, supplied by CMA producer member CEL Paving Products, were used for the permeable surface. Designed by KLS Consulting Engineers, the installation complies with Cape Town’s City’s Management of Urban Stormwater Impacts Policy, which aims to reduce the negative impact of impermeable surfaces on aquatic eco-systems. K L S C o nsul ting E ngin e er s ga v e Checkers the option of installing either a small retention dam or a permeable paving system. The retailer opted for the latter, primarily because it did not require additional space. Instead, it forms an integral part of the parking lot, unlike attenuation ponds, which use up valuable space that might otherwise be used for parking or building purposes. Retaining water KLS associate engineer Carien Visser says permeable paving effectively retains a high percentage of stormwater on site and ensures that any water not infiltrated into the ground under the paving is released into the council’s stormwater system in a controlled manner via fin drains. “Moreover, the system’s layered sub-base structure of stones and locally manufactured geotextile membranes filters out most of the pollutants, including hydrocarbons, phosphorus, nitrogen and heavy metals. Our design was based on the assumption that 30% of the sub-base volume would comprise voids in which water is stored prior to dispersion into the ground or stormwater system,” she says.

PERMEABLE PAVING SYSTEM ADDS PARKING SPACE FOR SHOPPING MALL

The new parking area is situated on a

area revealed ugly oil stains on the

Asphalting. Starting from the bottom,

2 050m² site on Kloof Ave opposite the

parking bay surfaces. Therefore the

the permeable layered structure com-

main retail complex. The surface area of

parking bays were paved with asphalt to

prises a compacted sub-grade, a layer

the permeable paving is 830m², repre-

prevent oil from entering the permeable

of geotextile, a layer of 543mm clean

senting 40% of the total catchment area.

paving system and to minimise the impact

crushed stone, a layer of 19mm clean

of oil stains. The asphalt parking bay

crushed stone, a second layer of geotex-

Preventing oil ingress

sections fall towards and drain into the

tile, a layer of 6mm clean stone bedding

“Initially, the intention had been to cover

driveways which comprise the permeable

and screeding grit installed under and be-

the parking bays with the permeable

paving section,” adds Visser.

tween the PermeaLock paving blocks.

paving and the driveways with asphalt.

The sub-base layers were installed by

However, this application was reversed

Umzali Civils, the asphalt by ATS and the

after an inspection of the main parking

paving was done by Greystone Paving &

PRECAST | ISSUE ONE | 2019

(Above): The Checkers Langverwacht Plein permeable paving parking extension during construction.


PROJECTS 28

PRECAST CONCRETE PANELS FOR V&A Precast concrete panels have been used

sterdam Battery, which was built by the

This versatility, whether structural

to clad a structure at the V&A Water-

Dutch in 1784. This provided both a chal-

or decorative, provided an end-product

front urban park development, Battery

lenge and an opportunity for the design

that shows off exceptionally detailed

Park. Dubbed the Interpretation Pavilion,

and construction teams – paying homage

and finished concrete elements. It also

the concrete-clad structure references

to a historic landmark, while providing

references the robust nature of the

the site’s historical significance and links

leisure and parking spaces.

original Amsterdam Battery and the

the park, piazza and four-storey parkade via internal elevators.

The material palette includes a selec-

precast elements allowed for off-site

tion of hardy materials such as steel,

production and quality control. Cast in

Designed by dhk Architects to provide

an attractive light grey/off-white, the

new pedestrian routes and engage with

precast cladding for the Interpretation

the greater Cape Town community, Bat-

Pavilion was designed by dhk to create

tery Park includes an elevated park and

a façade in harmony with the other

lower-level piazza that effectively conceal

architectural themes at Battery Park.

a 1 206-bay parking facility. Situated along Dock Rd, a prominent entry point

Complex casting

to the V&A from Cape Town’s CBD, the

N u m b e r i n g 12 3, t h e p a n e l s w e r e

urban park plays a vitally important role

produced by CMA producer member

in terms of pedestrian traffic and con-

C oncr e te Units. T hey co ver ed f i ve

nects various V&A districts to the city

ex ternal elevations, as well as the

centre. In addition, the development fa-

internal walls of two elevator lobbies.

cilitates various recreational activities,

They also lined three splayed rectangular

including open-air events, skateboarding,

gun ports in the upper elevator lobby to

basketball, mini-football, swimming and

accommodate defunct cannons, much as

SUP rowing.

they would have done in an old fort or a

As the City of Cape Town no longer

man-’o-war.

promotes the vision of stand-alone

The smooth-bore muzzle-loading rel-

parking structures, the V&A required

ics date back to the 18th century and

a design that would utilise the upper

were discovered during site excavations

and lower “lef tover” spaces of the

at the V&A. Eighty percent of the panels

parkade. The need for a parking facility

had to be custom-made, with the re-

coincided with the proposal for a new urban park that would serve as a nucleus for a larger urban vision. dhk addressed these r equir ements by designing a

(Above, from top): The upper-level community park which effectively conceals the parkade below; the canal-facing piazza and behind it, a well-disguised parkade.

maining standard-sized units measuring 2 550 x 650 x 120mm. “Each panel required a full set of shop drawings and we used adjustable

publicly accessible park above the park-

stone and concrete, which suit the robust

moulds with large sof fits to accom-

ing facility and a piazza with space for

nature of the park. Concrete was chosen

modate the various shapes and sizes,”

shops and restaurants facing onto the

as “the material of our time”, since it is

says Concrete Units manager Brian

Roggebaai Canal.

clearly distinguishable from the historic

Cook. “Every unit was drawn in 3D and

elements. Both in situ and precast, the

our boilermakers had to take particular

Historical site

concrete used throughout the urban park

care in producing high-quality moulds.

The site also contains remnants of one

was of a high quality and included a variety

Avoiding casting lines and shutter joints,

of the city’s oldest structures, the Am-

of finishes and inventive applications.

the moulds also yielded crisp corners.

PRECAST | ISSUE ONE | 2019


tower crane. “Built with steel girders and measuring 4 400 x 1 145mm, the placement beam gave us not only finer vertical and horizontal adjustment, but also the required

PROJECTS

beam, which we suspended from the

reach for installing panels inside the two elevator foyers. Nevertheless, where possible and for sake of simplicity and speed, some of the external panelling was installed using a normal spreader beam. “And again, unlike the panel installation at Silo No 1, where a combination of corbels and dowels was the primary

A URBAN PARK

“This left us with no alternative but to

attachment mechanism, the panels at

use the main contractor’s tower crane.

Battery Park were bolted onto a galva-

Moreover, we had no access inside the

nised steel frame.

Heavy lifting

building, which meant that these panels

“We also supplied three-sided C panel-

“However, our biggest challenge on this

were also installed using the tower crane.

ling, which was attached to some of the

project was panel installation. Each

external beams at the entrance to the

weighed between 200kg and 1 500kg, the

Panel placement

upper-level elevator foyer, which used

latter being the maximum carrying capac-

“However, there was a problem with this

grouted dowels,” adds Cook.

ity of the main contractor’s tower crane.

solution. The tower crane only catered

“Whereas we used our own crane for

f or coar se adjustments of r oughly

the installation of the panelling at the

100mm increments and we were working

V&A’s No 1 Silo, we weren’t able to do so

with 15mm gaps between panels, which

at Battery Park because the perimeter of

of course required finer adjustment.

the structure resembled a five-sided poly-

T he solution involved designing and

gon, which required multiple crane set-ups.

assembling our own panel placement

(Top, from left): Precast concrete cladding supplied by Concrete Units was designed by dhk Architects to create a façade in harmony with the other Battery Park architectural themes; the upper section of the Interpretation Pavilion. It includes lined wall cavities for display purposes and gun ports for two muzzle-loaders, 18th-century rusted relics from the original Amsterdam Battery.

29


PROJECTS 30

CARBON FIBRE PLATES STRENGTHEN GATEWAY ROOF SLABS The conversion of a roof parking area

a leading position in the development

sidiaries in 100 countries around the

at Umhlanga’s Gateway Mall into ad-

and production of systems and products

world and manufactures in over 200

ditional shops and a hotel meant that

for bonding, sealing, damping, reinforcing

f a c t o r i e s . I t s m o r e t h a n 18 0 0 0

concrete beams and roof slabs had to

and protecting in the building sector

employees generated annual sales of

be strengthened to take the additional

and automotive industry. It has sub-

CHF6,25 billion in 2017.

loading which the conversion entailed. This was achieved by bonding Sika Carbodur carbon fibre plate, S1014 (7 300m) to the beams and roof slab soffits using Sikadur-30. Sika Carbodur plates are pultruded carbon fibrereinforced polymer laminates designed for strengthening concrete, masonry and steel structures. Sikadur-30 is a primerless structural epoxy adhesive which bonds Sika Carbodur to concrete, masonry and steel. The high strength and excellent durability of the Sika Carbodur made it the ideal choice for this application. Challenging time constraints (contractor Amsteele Systems was given only six weeks to complete the project) meant that the correct products needed to be applied effectively and quickly. Sika (a CMA non-producer member) is a specialty chemicals company with

(Above): The partially completed roof reinforcing at Gateway Mall using Sika Carbodur.

A NAME TRULY CAST IN CONCRETE

GAUTENG | KZN | WESTERN CAPE

PRECAST CONSTRUCTION SOLUTIONS HEAD OFFICE: (011) 589 8800 WWW.ECHO.CO.ZA


PROJECTS 31 In addition to the precast concrete cladding used on the Interpretation Pavilion at Battery Park, several other precast concrete elements were specified by dhk Architects for the construction of this urban park and parking facility development. These included concrete plinths to support the two historic cannons mounted inside the elevator foyer, a precast staircase with seat treads which leads from the piazza to the upper-level recreation area and precast concrete benches, as well as precast concrete paving on the upper-level park and recreation area which was supplied by CMA producer member Revelstone. The central concrete staircase and the steps adjacent to the canal were finished with off-shutter precast concrete treads, while some sections of the upperlevel park were paved with Revelstone’s Jura Cobble and Jura Paver pavers. Approximately 40 concrete moulds were used for the precast concrete stair treads and seats and 10 moulds were required for the precast benches in the piazza. All the moulds were adjusted by

FURTHER PRECAST ELEMENTS ENHANCE BATTERY PARK PRECINCT the insertion of loose stop-ends which

with an acrylic compound. The polishing

were made of either timber or concrete.

was done with wall-mounted table-top

The cannon bases and corner bench slabs

machines and hand-held machines.

were cast in timber moulds. The bench

Recycled course aggregate, Philippi

slabs were cast on a concrete table, each

sand and OPC were used for the bench

one measured to suit.

casting. No curing agent was used in

The treads were made using OPC and

either the precast benches or the treads

quarry dust from Afrimat’s Palmiet quar-

due to the possibility of colour variation.

ry, which had enough fines to preclude

They were simply cured for longer.

the need for additional sand. The tread mixture also included exposed aggregate for a non-slip surface and SIKA Lite for water-resistance and additional surface enhancement. After initial curing, the treads were washed, polished and sealed

PRECAST | ISSUE ONE | 2019

(Above, left): The precast concrete seat staircase and seat treads. (Above): Revelstone’s Jura Cobbles provide some of the hard landscaping on one of the Battery Park walkways. (Left): Jura Paver stepping stones lead onto the mini-soccer pitch at Battery Park.


PROJETCS 32

HERITAGE AND FUTURE

that it glows for up to eight hours during

Concrete has been synonymous with durable infrastructure – and thus civilisation itself – since the earliest times. Thanks to ongoing R&D, it looks set to be the building material of the future as well.

power consumption. Perhaps we are not

darkness – a great boon for lighting up walkways and the like, thereby reducing far off concrete embedded with sensors that provide data to building managers. One thing is certain: innovation will

Any civilisation is all about its struc-

new qualities, such as plasticity and the

not stop and will ensure that concrete

tures – not only palaces, temples and

ability to flow easily, as well as the crea-

remains not only one of the most de-

government buildings, but also public

tion of new types of surface and colour.

pendable and durable building materials,

spaces and the homes o f or dinar y

Concrete has gone from being seen

but also one that increasingly allows

citizens. A successful civilisation must

as a relatively utilitarian building mate-

us to create whatever we can imagine.

also be able to build infrastructure to

rial to one that can achieve spectacular

facilitate the movement of people and goods, and bring water to urban dwellers. Concrete has been, and remains, one of the key building materials for all of this vital infrastructure. Daniel van der Merwe, innovation architect at PPC Group Services, says that whereas Middle Eastern builders traditionally used a paste of burnt limestone to protect their clay buildings, in today’s high-rise structures, concrete has changed construction

“Concrete has gone from being seen as a relatively utilitarian building material to one that can achieve spectacular aesthetic effects.”

Improving society Concr ete is mor e than an integral enabler of the infrastructure a civilisation needs – it can also be used to create structures and spaces which are intended to realise ideals. Thus while roads, dams and office blocks, etc, are critical pieces of infrastructure, they basically support the status quo. However, other types of structure have a purpose which is further-reaching and helps transform society. It is this type of transformative in-

methods beyond all recognition, thanks to intensive and continuous research

aesthetic effects: one has only to think

frastructure that grabs PPC’s collective

and development by scientists and the

of the famous “sails” of the Sydney Op-

imagination and underlies some of the

major suppliers themselves.

era House. Indeed, nowadays concrete is

exciting projects we are involved in as

even being used successfully to fashion

part of our corporate social investment

sculptures and jewellery.

initiatives. They showcase not only con-

Better product As a result, not only is concrete more

In similar vein, we are also seeing

crete’s versatility as a building material,

durable and easier to work with, but a

concrete with added aluminium silica

but also its ability to support new ideas

bewildering array of additives have added

which absorbs light during the day so

in the real world.

PRECAST | ISSUE ONE | 2019


being imposed on it. The project is

Conceived by artist Erhardt Thiel, the

ongoing and plans to repair and expand

iMadiba project aims to create public

1to1 – Agency of Engagement at Slovo

the community hall are advanced. This

spaces across SA that encourage dia-

Park, south of Soweto. The idea was

new initiative aims to empower the

logue between all citizens by providing

born out of a student project and aimed

local youth forum both by doing the work

a place to sit and have conversations.

to change the way this politically sensi-

and then using the hall to undertake

tive informal settlement was regarded,

various projects.

Three installations have been unveiled (Robben Island Gateway, the V&A Wa-

to create a common space that would

Slovo Park is a pilot for a larger

terfront and outside the Johannesburg

have the buy-in of the community, thus

programme aiming to start 25 such

Stock Exchange (JSE)) and more are

providing a foundation for development.

projects by 2020. Like this one, they all

planned. Concrete truly is the material

aim to realise PPC’s purpose of helping

not only of the past and present, but

everybody enjoy a better quality of life.

also – as these examples show – for

Community input

PROJECTS

One example is the collaboration between PPC and non-profit organisation

A n impor tant r ealisation was that

Another initiative centred on re-

architectural design and planning could

imagining how public space could be used

and should be done in collaboration

was inaugurated to celebrate the legacy

(Far left): Concrete structure at the JSE.

with the local community, rather than

of former President Nelson Mandela.

(Below): Workers transform spaces with concrete.

33

shaping our collective future.

We are there when you need support

Need help with your concrete? We offer a free advisory service for general concrete queries. Perfect concrete with us.

www.theconcreteinstitute.org.za +27 11 315 0300


PROJECTS 34

FIRST GREEN HOUSING SOLUTION IN PRETORIA CMA producer member Technicrete

the project managers to have hands-on

was selected to supply its Enviro-Wall

exposure to the benefits of the retaining

retaining wall blocks, base blocks and

wall technology in creating multiple ter-

keystone paving for the eco-friendly

races with ease. For over 18 months we

and energy-efficient Greenhill Estate, a

collaborated in order to supply a product

residential estate on top of Waterkloof

with which the engineers and develop-

Hill in Tshwane.

ers were completely satisfied – not only

Greenhill, developed by the Green

in terms of its performance, but also

Housing Company, comprises 39 ex-

in terms of the final appearance of the

clusively designed units. The develop-

retaining wall, which we supplied in the

ment star ted in August 2017 and

required tan colouring.

Technicrete’s Enviro-Wall retaining wall

retaining wall system. Opening or closing

technology was specified by the project

Complex site

the spacing between the blocks enables

consulting engineers. Construction was

“Once the Greenhill Estate entered the

the Enviro-Wall structure configuration

carried out by Piet Bok Construction.

construction phase, it was important

to be altered so that in the open arrange-

“The benefits gained from Enviro-

for me to ensure that the system was

ment, cavities between adjacent blocks

Wall’s technology were par ticularly

installed according to specifications in

can be filled with soil, promoting plant

relevant to the Greenhill project due to

order to maximise its overall effective-

growth. It can also be installed as a solid

each stand being developed at different

ness. To this end, I regularly inspected

engineering structure.

levels, thereby requiring good, sturdy and

the site. Situated at the top of a koppie,

attractive retaining wall installations,

the project has been the most complex

Multi-purpose

with no risk of soil erosion,” says Piet

site I’ve ever seen from a platform per-

“The blocks are suitable for supporting a

Pretorius of Piet Bok Construction.

spective, with almost all of the 39 stands

wide range of embankment heights and

being at completely different levels.

the wall can accommodate both concave

“This required many walls at different

and convex alignments down to a small

Technicrete’s Justin Kretzmar explains:

levels, weaving in all directions and tying

radius of 2m. With the custom-designed

“We worked on the designs of these

into each other as and where required.

Base Block, the angle of the inclination

walls with the engineers on the Greenhill

We opted for a wall design reinforced with

of the wall is easily set out at 700, but

Estate project long before commence-

horizontal structural geogrids and to this

can be varied if site conditions require

ment of bulk earthworks to show how

end, the Enviro-Wall block – due to its

something different,” says Kretzmar.

the Enviro-Wall technology offered the

shape and interlocking pattern – offers

He adds that Technicrete’s Keystone

best retaining wall solution to this multi-

the best ‘key’ to secure the geogrids

paving was utilised for all the estate’s

levelled project. Wall heights ranged from

from pull-out.

main roads. The pavers combine two dis-

Close collaboration

1-6m, requiring a single design philosophy

“This is possible due to the wall, which

tinctive shapes into one unit, making it an

that could be used across the board,

is constructed from dry stacked inter-

attractive option for driveways, parking

keeping it simple while still remaining

locking, precast blocks. The simplicity of

areas and access roads.

cost-effective and within budget.

the blocks’ design enables them to be

“We provided factory samples for

easily and quickly laid to form an effective

(Top and above): A retaining wall under construction at Greenhill Estate in Tshwane.

PRECAST | ISSUE ONE | 2019


A little bit of magic is to be found just

been applied throughout the estate. The

outside Polokwane in the form of The

DZZs from Technicrete have given The

Aloes Lifestyle Estate, which – since its

Aloes a very upmarket and aestheti-

inception nine years ago – has continued

cally pleasing, yet practical finish. We

to expand its upmarket residential and

utilised Rocla’s [a CMA poducer member]

retirement living concept. The tranquil and

stormwater pipes and sewer manholes

exclusively designed estate contracted

during the Phase One and Phase Three

CMA producer members Technicrete and

expansions for water run-off from the

Rocla for its paving, kerbs, pipes, culverts

roads into kerb inlets.”

and manhole requirements. “The entire Aloes Lifestyle Estate

(Above): Extensive paving inside The Aloes residential and retirement living concept.

Stormwater management

project, from Phase One in 2010 to

“Our manhole components at The Aloes

Phase Five in 2018, has chosen and

have been utilised f or stormwater

installed Technicrete paving and kerbs.

applications at the estate, but are also

Good quality, longevity and affordability

used in sewer applications,” says Robert

are among the factors which made Tech-

Hill from Rocla.

nicrete a preferred choice of supplier,”

Technicrete’s range of DZZ interlock-

says Leon Labuschagne, site agent for

ing pavers form a hard-wearing surface

Oscon Electrical & Civil Contractors.

overlay which is perfect for application

“Near l y 7 000 ker bs o f v ar ious

in lifestyle estates, as well as for petrol

dimensions and 15 700m 2 of Double

forecourts, municipal parking areas,

Zig-Zag [DZZ] 60mm grey pavers have

commercial developments and heavy-

PROJECTS

PAVING POLOKWANE RESIDENTIAL AREA

35


RPOJECTS

duty industrial areas. The pavers form a herringbone pattern, once installed. Rocla’s precast concrete manhole comprises an interlocking joint profile which makes installation quick and effective. When required, a sealant can be utilised between sections to ensure

36

the chamber remains watertight. The manholes are a maintenance-free, highquality solution. Avoiding theft Compared with cast-iron manhole lids, Rocla’s precast concrete lids offer no

“The tranquil and exclusively designed estate contracted CMA members Technicrete and Rocla for its paving, kerbs, pipes, culverts and manhole requirements.”

The pipes are manufactured in 2,44m and 1,22m, but can be manufactured in special lengths to customer specification. The standard strength classes f or these pipes ar e 50D, 75D and 100D (refer to SABS 677). Special intermediate strengths or heavier loading requirements can be designed and manufactured. These are subject to various material constraints, but can be evaluated by Rocla engineers as required. Form and function “Lifestyle estates such as The Aloes

resale value and are less likely to be re-

depend heavily on the functionality and

moved from site. The manhole sections

appearance of products that are finally

are supplied in lengths of 1 000mm,

installed at such upmarket developments.

500mm and 250mm and are available

The products selected from Technicrete by

in diameters of 750mm, 1 000mm,

Oscon Electrical & Civil Contractors are of

1 250mm, 1 500mm and 1 800mm. Spe-

a high quality and provide a lifespan suited

cial sizes can also be accommodated.

to the traffic requirements of the estate,”

Although Rocla’s stormwater pipe

says Mishack Mdhlululi, Technicrete’s sales

is primarily designed for use in a non-

consultant for the Polokwane region.

watertight pipeline, rubber collars can be

“A combination of mountable and semi-

supplied to facilitate a measure of water-

mountable precast kerbs was selected

tightness. These can be used in instances

which gave a superior edge restraint

where ingress of groundwater needs to

finish. We were delighted to have been

be avoided, making the more expensive rubber ring joint pipe unnecessary.

(Above): A Rocla manhole installed at The Aloes Lifestyle Estate in Polokwane.

involved in the development and expansion of The Aloes Lifestyle Estate.”


PROJECTS 37

METRORAIL SAFETY WALL BUILT WITH ECHO PANELS Pre-stressed concrete panels supplied

discourage people from tunnelling under

vantages to this type of walling, speed

by the Echo Group (a CMA producer

the wall. This panel rests on two rein-

of construction and cost being major

member) have been used for a safety

forced concrete footings at each end of

considerations.

wall which has been built adjacent to

an installation bay and supports the two

a railway line in Tembisa, Gauteng. The

slabs above it.

“Eight to 10 bays, or 48-60 linear metres, were completed daily (eight hours).

construction of the wall is the first of

The footings measured 1m x 1,8m x

A conventional masonry wall would have

what will probably be several building

400mm (depth) and were cast on 450mm

taken two or three times as long, with

phases which, when completed, will see

re-compacted, cement-stabilised soil.

no advantage gained in strength or

walling erected on both sides of the

The beam sections were delivered to

durability. In fact, because our panels

30km Metrorail link between Tembisa

site with base plates and flanges already

have a compressive strength of 50MPa,

and Germiston.

attached. After being bolted onto the

they’re virtually indestructible,” says

footings, laser levelling was used for

Esterhuizen.

The project is being undertaken on behalf of the Ekurhuleni Metropolitan

vertical alignment.

Byron Haarhoff, managing director

Municipality and PRASA, principally to

of BKH Construction, adds that Echo’s

prevent pedestrians (especially school

panels come with smooth soffits and do

children) from crossing or walking along

not require maintenance. “They also have

the track, endangering life and limb.

a tongue-and-groove jointing system to

Several fatalities have occurred among

ensure that adjoining panels form a tight

children and adults unaware of oncom-

seal. Moreover, Echo cut out 200mm

ing trains.

x 200mm sections at each end of the

The Phase 1 component is 1,8km

anti-trenching panels to ensure a snug

long. It was designed and built by BKH

fit over the steel flanges, which provide

Construction as a sub-contractor to civil

additional support for the steel uprights.

contractor, Pamodia Projects. The design

“Before actual site work commenced,

was approved by Aurecon Consulting

Thereafter the panels were slotted

we worked hand-in-hand with local

Engineers, based on an analysis of the

between the beam sections by truck-

businesses and community members,

area’s prevailing geotechnical conditions.

mounted crane. Each panel was 120mm

apprising them of what the work would

In addition, two pedestrian subways were

thick, as opposed to the I-section chan-

entail and gaining their assistance in the

constructed by Pamodia Projects under

nels, which were 150mm wide. This left

recruitment of local labour. We use local

the section flanked by the wall, using

a gap of 30mm which was filled with non-

community members in all our projects

precast concrete culverts.

shrinking grout. Wooden wedges were

and in this instance, we upskilled locals in

used to hold the panels flush against one

concrete compaction, the drilling of bolt

Simple solution

of the inner sides of the beam sections

holes, bolting, grouting and the type of

The wall was built simply by sandwich-

to facilitate the grouting process. After

steel we were using for the uprights,”

ing three 6m-long panels between two

three days, the grouting had cured suf-

says Haarhoff.

3m-high galvanised steel beam sections.

ficiently for the wedges to be removed

Two of the panels were 120cm wide and

and the remaining gaps caulked.

were positioned above natural ground level, yielding a wall height of 2,4m. The

Compressive strength

third or anti-trenching panel was 600mm

Echo Group marketing director Melinda

wide and was installed below ground to

Esterhuizen says there are several ad-

PRECAST | ISSUE ONE | 2019

(Top, from left): A partially completed section of the wall in which Echo’s smooth soffits and the close-fitting tongue-and-groove jointing are seen to good effect; a completed section of the wall. (Above): Byron Haarhoff (left) with some of the Tembisa residents who assisted with the construction of the wall.


PROJECTS

LOCAL WINE PRODUCERS SWITCH TO CONCRETE FERMENTATION TANKS Several South African wine producers are following a global trend of fermenting wine

38

in concrete tanks. It might surprise some to know that fermentation in concrete actually has a long history in European vineyards and is used across France in the Rhône Valley, Burgundy and Bandol. Accor ding to well-k nown Fr ench wine master, Christophe Baron, “you can’t have a great wine without great mouth feel – and concrete is all about mouth feel”. “Concrete allows for the gradual oxygenation of the wine, similar to oak barrels, but without the purchased flavours of oak barrels,” says James Mantone of Syncline Wine Cellars in Washington State, USA. “This gives

During the 2018/19 wine season, Ikapa

a truer taste of the vineyard without

Concrete contracted CMA producer

oak aromas or sweetness to cover up

member Concrete Units to produce

deficiencies in the fruit.”

approximately 30 of the egg-shaped

(Above): The Concrete Units factory where eggshaped wine tanks await delivery. (Below): A rectangular wine tank nears completion at the Concrete Units factory.

tanks, in addition to some larger, cubeClever design

shaped units. The ovate tanks have a

On the local front, the development of the

1 520l capacity, while the rectangular

concrete wine tank has been conceptu-

tanks come in four sizes: 2 550l, 6 000l,

alised and pioneered by Ikapa Concrete.

8 000l and 10 000l. Moreover, Concrete

The company’s owner, Dougie Atter-

Units has also made Ikapa’s Petite, an

bury, says that after many years of using

egg-shaped tank, which – as its name

large, epoxy-coated concrete wine tanks,

suggests – is the baby of the bunch, with

new advances in concrete technology

a capacity of only 36l.

have heralded the launch of an uncoated, egg-shaped range of tanks which not only

Egg tanks

finding favour with concrete wine tanks,

breathe, but enhance the quality of the

Concrete Units manager Brian Cook says

including Eikendal Wines, Elgin Ridge Wine

final product.

the manufacture of concrete wine tanks

Estate, Joostenberg Wines, Laibach

required very specific concrete mixes.

Wines, Zevenwacht Wine Estate, Steen-

“Besides precise mix quantities, the

berg Wines and Waterkloof Wine Estate.

water had to be chlorine-free and the

Af ter the wine production period

epoxy, which was used to attach various

from December to February ended,

stainless steel components to the tank,

Ikapa commissioned Concrete Units to

had to be food grade. We used fibreglass

manufacture concrete water storage

moulds and fibre-reinforced concrete

and conservancy (sewerage) tanks during

for the egg tanks and this required

the course of 2019.

maintaining a fine balance between slump

“Some local governments in the

and vibration. We also used a high-quality

Western Cape don’t permit underground

aggregate which took the form of washed

plastic water and conservancy tanks due

granite, sourced in Malmesbury, some

to the fact that they’re prone to rise out

considerable distance from our factory.

of the ground in areas with high and rising

“Casting the egg tanks in fibreglass

water tables. Overstrand, which includes

moulds was very challenging and we had

Hermanus, Betty’s Bay, Kleinmond and

to work very hard to achieve smooth,

Gansbaai, is one such area. Moreover,

blowhole-free finishes,” says Cook.

rising groundwater has seen plastic tanks ‘popping’ in Stellenbosch and

(Above): The 36l Petite.

Growing trend

they’ve been replaced with concrete

Numerous South African producers are

tanks,” says Cook.

PRECAST | ISSUE ONE | 2019


CAST-STONE PAVERS SELECTED

FOR CAPE HOUSING

Kent cobble and Ravine pavers have been used for the paving of driveways and pathways at Sunningdale, a Garden Cities middle-income housing project adjacent to the recently completed Tableview Mall on Cape Town’s Western Seaboard. The cast-stone pavers were produced by

Stuttaford. The inspiration for Garden

CMA producer member Revelstone, which

Cities came from the revolutionary Brit-

also supplied its Ravine pavers for paths

ish Garden City movement started by

and patios in the residential precinct. In

Ebenezer Howard, whose objective was

addition, Revelstone has supplied another

to build entire new towns and improve

Garden Cities development, Pinehurst in

the poor living conditions in parts of

Durbanville, with Kent cobbles and Ravine

Britain during the late 19th and early

pavers for similar applications.

20th centuries.

Founded in 1919, Garden Cities is a

Revelstone has been producing cus-

non-profit organisation which develops

tomised cast-stone products since 1993

entire suburbs. The company says its

for both the domestic and commercial

main purpose is “to provide better

markets. Family-owned, the company

housing and social conditions for the

uses traditional masonry skills combined

people, the latter to be construed in its

with modern moulding techniques to pain-

widest sense”.

stakingly produce master moulds from

In addition to constructing high-quality

original stone. This hands-on approach

houses and public buildings, Garden

allows the creation of custom-made

Cities fosters equality in education by

products, enabling Revelstone to supply

providing school halls to redress decades

pavers and cladding uniquely tailored to

of disadvantage.

its clients’ specific requirements.

The current chairman, Sean Stuttaford, is the great-grandson of the founder, Cape Town businessman, Richard

PRECAST | ISSUE ONE | 2019

(Above): Revelstone’s Ravine pavers (pathway) and Kent cobble (driveway) make for an attractive combination at Sunningdale.


PROJECTS 40

THE JBCC ON DEALING WITH CONFLICTS OF INTEREST IN SITE CLAIMS Disputes and consequent claims on building sites are nothing new and resolving such situations invariably calls for time, patience and skills. But the problem is sometimes exacerbated when a conflict of interest unexpectedly crops ups, says Uwe Putlitz, CEO of the Joint Building Contracts Committee (JBCC).

with a claim from the contractor for

with execution criteria within stipulated

additional costs and/or an extended con-

time periods and along agreed proce-

struction period – and then finds that the

dures must be followed,” he adds.

cause for the claim is non-performance or

Putlitz adds that because the causes

incompetence by an individual employed

of conflict on building sites are so var-

by his very own firm. “It could actually be

ied, it is essential that the client at the

far worse: not only could the culprit be

outset determines an effective com-

working for the same firm of consultants,

munication strategy involving all project

but he or she could even be the principal

participants throughout the design and

agent or the project manager.”

construction phases, together with the

Putlitz says that in such cases, only

delegated levels of authority of team

two solutions are available:

members. “This procedure would simplify

• The principal agent must immediately

the avenues to follow when disputes of

notify his or her company’s profes-

any type arise,” he advises.

sional indemnity insurer and then,

collectively, the client as well to make

a fair determination of the claim in

consultation with the insurer – and

accept responsibility for the costs

thereof; or

• Appoint another agent to deal with the claim in question – and immediately notify his or her professional indem-

The JBCC is a non-profit company which

nity insurer to resolve the degree of

represents building-owners and develop-

liability and costs thereof.

ers, professional consultants, and gen-

“Sweeping the issue under the pro-

eral and specialist contractors who all

verbial carpet definitely isn’t a solution.

provide input for the compilation of JBCC

A n unknown writer once obser ved:

agreements (contracts) that portray

‘Contracts are there to allocate blame.’

the consensus view of the committee’s

Indeed, standard forms of construction

constituent members.

contract have been drafted to be ‘just’

Putlitz says difficulties may arise

and ‘fair’ to both parties – but to achieve

(Top): The JBCC building site.

when a project’s team leader must deal

this, the provisions of the clauses dealing

(Above): Uwe Putlitz, CEO of the JBCC.

PRECAST | ISSUE ONE | 2019


DRONES MAY BE THE ANSWER TO RESOLVING DISPUTES Drones hovering over and transmitting photos from building sites could in future play an important role in resolving disputes in construction contracts, says Uwe Putlitz, CEO of the Joint Building Contracts Committee (JBCC). T he JBC C is a non-pr o f it company

safely used in the location of a project,

which represents building-owners and

according to legal stipulations – can show

developers, professional consultants,

“hidden” aspects of the works by flying

and general and specialist contractors

over relatively inaccessible areas on site.

who all provide input for the compilation

The drones can even inspect adjacent

of JBCC agreements (contracts) that

properties to ensure that no building

por tray the consensus view of the

materials have accidentally been dropped

committee’s constituent members.

on them from cranes. “Dispute resolution

Putlitz says the advent of digital

almost inevitably involves prolonged post-

photography and incorporation of cameras

incident meetings, with unproven claims

in mobile phones in the past decade have

delaying finalisation. Now, with drones in

already helped tremendously to show

attendance, parties involved could table

progress or identify potential problems

photographic evidence from an ‘eye in

on building sites. “The new smartphones

the sky’. Drones open up totally new

have enabled parties involved with a

dimensions to validate claims.

building contract to obtain instant

“In addi tion to a dr one’s abili t y

photo or video recordings, incorporating

to measure building progress or

the date and time – essential information

spot defective work, the auto-pilot

in dealing with disputes. But hand-

systems could help health and safety

held or fixed cameras – however

officers timeously identify unsafe work

strategically positioned – can show only

procedures – an urgently needed tool

a pre-selected portion of a project and

to improve safety on site, which has

their use is also open to manipulation. The

already reached alarming low levels in

development of remotely piloted aircraft

SA,” Putlitz adds.

systems – so-called drones – has totally removed all these limitations.” Putlitz says drones – provided they’re

PRECAST | ISSUE ONE | 2019

(Below): The JBCC predicts that drones taking aerial photos of building sites could in future provide proof to speed up the resolution of many disputes.


PROJECTS 42

LOCAL MOULD MANUFACTURER

CRAFTS WINNING FORMULA Precast concrete mould producer Nigel Brown Moulds (NBM) is a success story which deserves to be heard, especially by aspirant entrepreneurs. NBM supplies thousands of moulds to 45 African countries annually. It also has customers as far afield as

We also do a lot of Vibracrete moulds.

If visiting customers are not convinced as

the UK and Australia. Fifty percent of

“Our fibreglass moulds generally

to the strength of these moulds, Brown

the company’s output is exported, while

last around five years, but the beauty

twists a 10-year-old rubber mould inside

the rest is supplied on the local market,

of fibreglass is that if it’s chipped or

out, stands on it and then smashes it

of which 90% is sold in Gauteng. NBM

damaged, it can easily be repaired. Our

with a hammer. When customers see

works in fibreglass, polyurethane (rubber)

customers are more than happy to repair

that no harm has been done to the mould,

and steel. Steel moulds were introduced

their own moulds. All it requires is some

they invariably buy the product.

in April 2018.

grinding, filler material and then sanding,

“We used to sub-contract orders for

and within half an hour, the repair’s done.”

steel moulds, but last year I invested

Founder and managing director Nigel Brown says he first began producing

in an imported steel CNC guillotine and

moulds for concrete products in Port

Durable solution

Elizabeth (PE) 18 years ago.

NBM’s rubber moulds, which are mainly used for the production of flagstone

Filling a gap

pavers, are extremely durable and are

“At the time, I was working for a nursery

generally good for 10 years’ production.

(Top, from left): Maltreating a rubber mould to demonstrate its durability and longevity; steel moulds to be used for kerb production. (Below): Nigel Brown Moulds’ recently-imported steel CNC guillotine and bending brake machine.

and our customers made r epeated requests for concrete products we didn’t stock. So I decided to make them myself. Initially I outsourced the moulds, but I soon realised that if I produced them myself, I’d make a better product. I then started selling the moulds and it wasn’t long before I became a specialist mould producer. I sold the PE business in 2001 and moved to George, where I founded Nigel Brown Moulds,” says Brown. “Fibreglass moulds produced by NBM are used for a diverse range of products, including concrete balls for driveways, building columns, flower pots, bird baths, benches, edging and other applications.

PRECAST | ISSUE ONE | 2019


give us the accuracy to produce identical m o u l d s f o r r e p e a t o r d e r s . We’r e currently making thousands of moulds for kerbs and are also producing moulds for retaining wall blocks. “In addition, last year we started manufacturing small vibration tables and concrete mixers branded as Outeniqua

“I spent the last week of November 2018 in Malawi after the client ordered a truckload of moulds.”

Rust Concrete Machinery. This required

“Part of the service we provide is free

us to expand into new factory premises.

training. For example, I spent the last

Our philosophy is to keep the weight of

week of November 2018 in Malawi after

our tables, which use electric motors

the client had visited us in George and

imported from Italy, down to no more

had ordered a truckload of moulds. His

than 110kg so that they can be lifted

company makes hundreds and thousands

by five men,” explains Brown.

of bricks and blocks each day and he

PROJECTS

bending brake machine. These machines

43

wanted to start producing flower pots, Global venture

tables and benches, bird baths, etc.

“Most of our exporting is done via road

“I trained 10 people in that company

freight, with only a small portion going

in mixing the concrete for those ap-

by sea. Moulds are big and bulky, which

plications and lubricating the moulds.

“Our business in Africa doubled during

makes air freight very costly. We’ve

I showed them everything and when I

2018 and one of our first orders for 2019

found that the further north we go, the

left, they were producing a range of

was for 50 moulds which were sent to

greater the competition from European

concrete products. While I was there,

Brazzaville in the Republic of the Congo,”

companies. This is because north of

we also damaged a fibreglass mould on

says Brown.

the Equator, their transport costs are

purpose so I could show them how to do

cheaper than ours.

the repair work.

(Above): Nigel Brown and some of his fibreglass concrete moulds prior to shipping.

“Stopping advertising to save money is like stopping your watch to save time.” – Henry Ford

DON’T MISS OUT! Advertise your business in our next issue. For more information contact Linda Meyer on tel: 083 626 8814 or e-mail:linda.precast@gmail.com


MEMBER LIST 44

PRODUCER MEMBERS A FICK SEMENT WERKE BK TEL: (022) 913 1921 PROVINCE/COUNTRY: WC PILLAR: PB AVENG INFRASET (PTY) LTD TEL: (011) 876 5500/872 1713 PROVINCE/COUNTRY: GAUT PILLAR: PB/PI

ECHO FLOORS (PTY) LTD TEL: (011) 668 1900 PROVINCE/COUNTRY: GAUT ECHO PRESTRESS DURBAN (PTY) LTD TEL: (032) 947 3067 PROVINCE/COUNTRY: KZN HORIZON BRICK & CONCRETE TEL: (012) 943 3701 PROVINCE/COUNTRY: N/W PILLAR: PB

BANZI TRADE 31 (PTY) LTD T/A BRICKIT TEL: (011) 023 6708 PROVINCE/COUNTRY: GAUT PILLAR: PB/PI

LATEGAN CEMENT WORKS (PTY) LTD TEL: (021) 873 1154 PROVINCE/COUNTRY: WC PILLAR: PB/PI

BETA TILES (PVT LTD TEL: (263) 4333735 PROVINCE/COUNTRY: ZIM PILLAR: PB

MARLEY ROOFING (PTY) LTD TEL: (011) 316 2121 PROVINCE/COUNTRY: GAUT PILLAR: PB

BOSUN BRICK BRITS (PTY) LTD TEL: (012) 250 1711 PROVINCE/COUNTRY: NW

MOBICAST (PTY) LTD TEL: 086 111 2346 PROVINCE/COUNTRY: WC PILLAR: PB/PI

BOSUN BRICK MIDRAND (PTY) LTD TEL: (011) 310 1176 PROVINCE/COUNTRY: GAUT PILLAR: PB/PI BOSUN BRICK PORT ELIZABETH (PTY) LTD TEL: (041) 405 0100 PROVINCE/COUNTRY: EC C.E.L. PAVING PRODUCTS (PTY) LTD TEL: (021) 905 5998 PROVINCE/COUNTRY: WC PILLAR: PI CEMBLOCKS (PTY) LTD TEL: (014) 538 0311 PROVINCE/COUNTRY: NW PILLAR: PB/PI CEM BRICK MANUFACTURERS (PTY) LTD TEL: (051) 433 4479 PROVINCE/COUNTRY: F/STATE PILLAR: PB/PI CIVILWORKS (PTY) LTD REAL TIME INVESTMENTS TEL: (011) 903 7023 PROVINCE/COUNTRY: GAUT PILLAR: PB/PI CONCRETE UNITS (PTY) LTD TEL: (021) 386 1923/ (016) 362 2236 PROVINCE/COUNTRY: WC/GAUT PILLAR: PB/PI CONFRAMAT (PTY) LTD TEL: (0861) 33 5599 PROVINCE/COUNTRY: GAUT PILLAR: PB/PI

MONIER COVERLAND (PTY) LTD TEL: (011) 222 7300/7334 PROVINCE/COUNTRY: GAUT PILLAR: PB MVA BRICKS CC TEL: (012) 386 0050 PROVINCE/COUNTRY: GAUT PILLAR: PI PANDA (PTY) LTD TEL: (00267) 244 2107/8 PROVINCE/COUNTRY: BOTS PILLAR: PB/PI PORTLAND HOLLOWCORE SLABS (PTY) LTD TEL: (021) 972 1111 PROVINCE/COUNTRY: WC PILLAR: PI REMACON PRODUCTS CC TEL: (011) 393 5504 PROVINCE/COUNTRY: GAUT PILLAR: PI REVELSTONE (CAPE) (PTY) LTD TEL: (0861) 173 835/(021) 761 9737 PROVINCE/COUNTRY WC PILLAR: PI ROCLA (PTY) LTD TEL: (011) 670 7600 PROVINCE/COUNTRY: GAUT PILLAR: PB/PI SHUKUMA BRICKS (PTY) LTD TEL: (041) 372 1013 PROVINCE/COUNTRY: EC PILLAR: PB

VANSTONE PRECAST (PTY) LTD TEL: (012) 541 2056/1808 PROVINCE/COUNTRY: GAUT PILLAR: PB/PI VIBRO BRICKS AND PAVING (PTY) LTD TEL: (012) 374 5533 PROVINCE/COUNTRY: GAUT PILLAR: PB/PI WEST END CEMENT BRICKS (PTY) LTD TEL: (011) 851 1005 PROVINCE/COUNTRY: GAUT PILLAR: PB/PI NON-PRODUCER MEMBERS ABEL EQUIPMENT CC TEL: (044) 874 1876 PROVINCE/COUNTRY: EC BASF CONSTRUCTION CHEMICALS SOUTH AFRICA (PT Y) LTD TEL: (011) 203 2400 PROVINCE/COUNTRY: GAUT BIRKENMAYER H (PT Y) LTD TEL: (011) 970 3880 PROVINCE/COUNTRY: GAUT CHRYSO SOUTHERN AFRICA (PT Y) LTD TEL: (011) 395 9700/ (031) 564 0325/(021) 928 1660 PROVINCE/COUNTRY: GAUT/ KZN/ WC DICK KING LAB SUPPLIES (PT Y) LTD TEL: (011) 499 9400/ (031) 700 2551 PROVINCE/COUNTRY: GAUT/DBN FIBERTEX SOUTH AFRICA (PT Y) LTD TEL: (031) 736 7100 PROVINCE/COUNTRY: KZN HAWKEYEPEDERSHAAB TEL: 00 459645 4193 PROVINCE/COUNTRY: DENMARK KERNEOS SOUTH AFRICA (PT Y) LTD TEL: (011) 444 3090 PROVINCE/COUNTRY: GAUT 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 SIKA SOUTH AFRICA (PT Y) LTD TEL: (031) 792 6500 PROVINCE/COUNTRY: KZN

CORESLAB (PTY) LTD TEL: (087) 232 2462 PROVINCE/COUNTRY: LIMPOPO PILLAR: PB/PI

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

COROBRIK (PTY) LTD TEL: (031) 560 3252 PROVINCE/COUNTRY: KZN PILLAR: PI

SILVERTON PRECAST (PTY) LTD TEL: (012) 804 4525 PROVINCE/COUNTRY: GAUT PILLAR: PI

DERANCO PRECAST (PTY) LTD TEL: (041) 463 3338 PROVINCE/COUNTRY: EC PILLAR: PB/PI

SMARTSTONE (PTY) LTD TEL: (011) 310 1161 PROVINCE/COUNTRY: GAUT PILLAR: PB/PI

EAGLE ROOF TILES (PTY) LTD TEL: (044) 874 0290 PROVINCE/COUNTRY: WC PILLAR: PB

TECHNICRETE (PTY) LTD TEL: (011) 672 1425/670 7600 PROVINCE/COUNTRY: GAUT PILLAR: PB/PI

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

ECHO PRESTRESS (PTY) LTD TEL: (011) 589 8800/8899 PROVINCE/COUNTRY: GAUT PILLAR: PB

TOPFLOOR CONCRETE (PTY) LTD TEL: (021) 951 7700 PROVINCE/COUNTRY: WC PILLAR: PB

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

TECHMATIK S.A. TEL: (0048) 608 422 300 PROVINCE/COUNTRY: POLAND TERRAFORCE (PT Y) LTD TEL: (021) 465 1907 PROVINCE/COUNTRY: WC

CIVILPRO ENGINEERING SOLUTIONS (PT Y) LTD PROVINCE/COUNTRY: JHB CONCRETE SOCIET Y OF SOUTHERN AFRICA TEL: (012) 348 5305 PROVINCE/COUNTRY: PTA CPI CONCRETE PLANT INTERNATIONAL TEL: (02236) 962390 PROVINCE/COUNTRY: GERMANY ILIFA AFRICA ENGINEERS (PT Y) LTD TEL: (012) 941 1616 PROVINCE/COUNTRY: PTA JC PAVING CONSULTING TEL: (011) 431 0727 PROVINCE/COUNTRY: JHB 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 BUFFALO RETAINING WALLS CC TEL: (016) 366 1801 PROVINCE/COUNTRY: GAUT DECORTON RETAINING SYSTEMS (PT Y) LTD TEL: (021) 875 5155 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 PPC LTD TEL: (011) 386 9000/909/626 3150 PROVINCE/COUNTRY: GAUT SEPHAKU CEMENT (PT Y) LTD TEL: (012) 684 6300 PROVINCE/COUNTRY: GAUT

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

PI – Precast Infrastructure PB – Precast Building

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

PRECAST | ISSUE ONE | 2019


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Precast • Issue 1 • 2019  

Precast • Issue 1 • 2019