ISSUE TWO • 2017
THE CMA – QUALITY CAST IN CONCRETE
• Getting roofing right • Meccano-style V&A parkade • Why CBR walls fail
COVER STORY 2
37 MAXIMISING PROPERT Y INVESTMENT
WHAT’S IN A MOULD?
INDUSTRY NEWS 5
CMA ACROSS THE COUNTRY
COASTAL FEEDBACK MEETINGS
GETTING ROOFING RIGHT
Q&A WITH THE CMA DIRECTOR
21 LONG-LASTING PAVERS 24 ENGINEERED SOLUTIONS FOR SOUGHT-AFTER LUXURY APARTMENTS 27 12M-HIGH RETAINING WALL SYSTEM
41 CONCRETE BIBLE UPDATED
40 ADDING GRACE TO HOUSING DEVELOPMENT
41 PHOTO CORRECTION
14 PRECAST ROADWAY SOLUTIONS GLOBALLY
17 NEW PAVING BLOCKS LAUNCHED 17 DEMOULDING MADE EASIER
32 MAKING SAFET Y A PRIORIT Y
19 MASONRY MANUFACTURING MACHINES
34 COST-CUTTING LEADS TO CBR WALL FAILURES
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: email@example.com 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: firstname.lastname@example.org Consulting editor: Raymond Campling Tel: 076 297 2775 E-mail: email@example.com
Coastal editorial: David Beer Tel: 082 880 6726 E-mail: firstname.lastname@example.org
ISSUE ONE • 2017
THE CMA – QUALITY CAST IN CONCRETE
Advertising: Wally Armstrong Cell: 083 701 3278 E-mail: email@example.com Subscriptions/Accounts: Thuli Majola Tel: (+27 11) 883 4627 E-mail: firstname.lastname@example.org Design and layout: Joanne Brook E-mail: email@example.com 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© 2017. 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.
• Getting roofing right • Meccano-style V&A parkade • Why CBR walls fail
ON THE COVER PMSA believes that a mould is one of the important tools in the brick, paving and hollow block precast manufacturers’ arsenal, as it has an immediate and direct impact on production in terms of volumes and quality produced. Contrary to the belief of some in the concrete manufacturing industry that a “mould is a mould”, there is sufficient evidence to prove that a carefully designed and well-made mould has the potential to turn a small profit into a bigger one.
COVER STORY 2
WHAT’S IN A MOULD? Contrary to the belief of some in the concrete manufacturing industry’s that a “mould is a mould”, there is sufficient evidence to prove that a carefully designed and well-made mould has the potential to save valuable time and material, increase productivity and turn a small profit into a bigger one. In fact, a mould is one of the important tools in the brick, paving and hollow block precast manufacturer’s arsenal, as it has an immediate and direct impact on production in terms of volumes and quality produced. Well-manufactured products also have indirect advantages further down the process, as there will be fewer rejects and packaging is simplified due to uniformity of shape and size. According to Quintin Booysen, PMSA sales and marketing manager, a quality mould will also produce more drops than standard ones and specialised wearresistance steels used in the manufacture of a mould will ensure that it maintains its dimensions to ensure uniformity of size and shape of the products produced. PMSA also offers more advanced moulds with replaceable wearing strips, mould inserts and shoes that can provide further advantages in terms of longevity and serviceability. Despite a higher initial purchase price, these deliver improved costs of ownership in the long run. Massive savings “For example, in a standard bevel paver of 100 x 200 x 60mm, the product should weigh approximately 2,52kg. If it were to wear-down just 1mm all around, it could lead to an extra 80g of material being required per unit. To put this into perspective: if a manufacturer makes 84 000 units per day, it can equate to an extra 134 tons of concrete or the equivalent of the material to produce 53 000 pavers per month. Using the same example on a maxi brick 290 x 140 x 90 mm, an extra 332 tons of concrete per month would be used due to only 1mm wear all round on a mould.
“A quality mould will produce more drops than standard ones.” PRECAST | ISSUE TWO | 2017
pricing and contribute further towards
possible returns on investment and give
reducing the cost per unit produced by
buyers the edge in a hotly contested
them,” says Booysen.
industry,” says Booysen.
According to Anthony Gracie of Cape Brick, the initial price of the PMSA Rock
Solid moulds is approximately one-third
As a wholly-owned, local company PMSA
mor e ex pensi v e than compe ti tor s’
also had the advantage of involving cus-
moulds, but have up to double the life-
tomers throughout the process of devel-
span with better tolerances and more
oping its range of moulds. This input and
accuracy, This ensures the products
refinement has led to the evolution of
are symmetrical and the right weight,
its moulds to the point where concrete
which amounts to big savings in mate-
manufacturers with PMSA moulds are
rial as well better equipment availability
getting more drops out of them due to
and vastly improved operational costs.
better surface hardening techniques
Booysen concludes that this type of
and materials being employed by PMSA.
attention to detail can give manufactur-
He adds that in the case of PMSA
ers a considerable advantage over com-
and its branded Rock Solid range, qual-
petitors through improved operations
ity is standard, with customers being
and lower life-cycle costs. “With good-
able to select the right kind of mould
quality aggregates, capable machines,
for their requirement in either solid,
correct settings and the right moulds,
welded or bolted moulds. “We looked at
manufacturers can set themselves up
different solutions based on common
to succeed. With the right maintenance
requirements of our customers and
and support from PMSA, their opera-
developed products to match these,”
tional success is another step closer.”
says Booysen. The company also invested heavily in technology to manufacture moulds that can compete with the very best in the world. But, says Booysen, local concrete manufacturers also enjoy the benefits of dealing with a home-grown company with fast turnaround times and easy access to spares. The additional access to technical support is a windfall and many a manufacturer has benefited from expert advice of PMSA support staff when servicing or selecting moulds that
(Above): Walter and Robert Ebeling of PMSA.
best suit their operations.
(Below and left): A premium-quality Rock Solid mould on display at the Totally Concrete 2017 exhibition.
Well supported “As a result, the savings on concrete
Customers also have access to PMSA’s
and labour over the period of this month
bespoke moulds that can be designed
are close to or even exceed the cost of
inhouse to strict requirements, with the
a quality new insert on a bolted mould.
additional benefit of being able to provide
But monetary value aside, of more con-
advanced surface finishes to create
cern to manufacturers should be that
unique and eye-catching products. This
units entering the marketplace from
type of ability allows manufacturers
worn moulds will be irregularly sized and
to move from a low-value product to
more difficult to place. This makes the
a higher-value product while still using
work of installers more difficult. As a
the same materials, processes and
result, the pavers will become unpopular
among the workforce and probably not be purchased again.
“Among the examples of our moulds in operation is Cape Brick, where our Rock
“Fur thermor e, our f indings have
Solid moulds have increased the mould
shown that quality moulds actually play
replacement intervals to almost double
a critical role in sustaining high levels
before needing a mould insert replace-
of production. As a result, we focus
ment. Even when they are worn, parts
our attention on manufacturing rugged
of the mould can be re-used to reduce
PRECAST | ISSUE TWO | 2017
and reliable moulds that deliver the best
YOUR QUALITY MARK IN PRECAST CONCRETE
Obtain your mark of approval from the leading authority in the precast concrete industry.
TRUST THE INDUSTRY EXPERTS Address: Office 0400, Standard Plaza Building, 440 Hilda Street, Hatfield, Pretoria, 0083 Tel: (011) 805 6742 • Email: firstname.lastname@example.org • Website: www.cma.org.za
CMA ACROSS THE COUNTRY While the political landscape has changed forever and revelations of state capture
make for nervous times, the Concrete Manufacturers’ Association has been quietly going about its business to pave the way for improved trading conditions for the industry – even in trying economic times. During the most recent round of regional meetings, executive director Frans Minnaar gave members insights into what has been an extraordinary year for the association. Successes and challenges
and addressed questions surrounding
the CMA Certification Service (CMA CS),
have been in equal measure and the overall
the end of an era during which cement
which had enabled the CMA to generate
result is that the association is emerg-
producer PPC acted as one of the main
money and assist in funding its efforts.
ing stronger and more self-sufficient
sponsors and supporters of the CMA.
than ever before. Self-sufficiency does
“Members will recall that PPC agreed
not mean isolated, though; by contrast,
to suppor t the CMA
While the CMA actively pursues growth
one of the first topics of discussion on
through tough times af-
through expanding its membership base,
the regional agendas was
ter the recession and
the CMA CS already finds itself with full
the CMA’s wholehearted
subsequent turmoil in
order books and a growing customer
endorsement of the
the economy. With the
base – which bodes well for the future.
industry’s very own
association now on an
Although the service is still awaiting
even keel and able to
SANAS accreditation, this has not de-
sustain itself, the PPC
terred manufacturers who are growing
agreement has been rescind-
increasingly anxious about the traditional
of the members of the
ed and we remain grateful for its
service provider, the SABS, and its ability
support. As with every down-cycle,
ence. T his marks the first collaboration
Industries body which
crete Institute (TCI) and the Concrete Society of Southern Africa (CSSA). The conference will take place on 17 and 18 August 2017 at the Misty Hills Conference Centre in Muldersdrif t, featuring presentations, case studies, how-to discussions and exhibitions that will showcase the country’s concrete abilities. The Concrete Conference will provide an opportunity to learn and en-
to provide timely certifications.
there’s also a natural upside, as headline
includes the CMA, the Southern Africa Readymix Association (SARMA), The Con-
Members’ complaints about the SABS include:
“The CMA has been quietly going about its business to pave the way to improve trading conditions for the industry.”
• Out-of-date certificates as a result
of excessively long waiting lists.
• Deferment letters which are issued
instead of actual certifications.
• Product buyers questioning the valid
ity of these SABS letters.
• Fears that unscrupulous manufactur
ers are taking advantage and operat-
ing from SABS letter to letter.
• The industry is questioning manufac
turers’ products, as they do not have
able delegates and exhibitors to network
sponsorships that had been automati-
confidence in current certification
and showcase their products. All CMA
cally held by PPC are now available to eve-
processes and some are opting to do
members can participate on a first-come,
rybody, which means associate members
first-served basis. “It’s about time that all
or suppliers may now secure exciting
“CMA members can rest assured
the concrete bodies stood together as a
sponsorship deals to brand and market
that CMA CS is aware of this sad state
united concrete industry. There’s also no
their products among CMA members.”
of affairs and is working hard to assist.
their own audits.
need for concern about working together,
Minnaar showed the positive state of
The CMA CS work ethic is considerably
as we each remain strongly independent,
the CMA’s financial affairs and allayed
more impressive. Since its inception in
but united in concrete,” said Minnaar.
concerns over the liquidity of the asso-
March last year, the team have set up
ciation, assuring members that meas-
the entire company structure, developed
ures had long been in place to reduce the
their own quality management system
Minnaar brought members up to date
association’s dependency on sponsors.
for members to address ISO 17065 and
with the finances of the association
Among these was the establishment of
handed the documentation to SANAS.
PRECAST | ISSUE TWO | 2017
Coverland and Marley. Minnaar also
aren’t quite as quick or responsive as the
Wrapping up the proceedings, Minnaar
praised Precast magazine, which is grow-
CMA’s own service. At the time of the
mentioned other achievements, such as
ing in stature and expanding its reach
regional meetings, the CMA CS had al-
the success of Internet marketing, work-
to a distribution list of 5 000 individuals
ready awarded accreditation certificates
shops and the growth of Precast maga-
to nine members, with several more set
zine. The revamped website continued
to follow,” said Minnaar.
to be a popular destination, with many visits daily. The paving
The efforts of the electronic and print publications dovetailed perfectly with the association’s other
workshop given by Tony Mc-
efforts to inform and educate
Meanwhile, despite the challenges the
Cormack, expert and author of
the market and provided a
industry has faced, membership of the
www.pavingexpert.com, was a
basis from which members
CMA remained constant, with new mem-
great success and was well at-
could access further informa-
bers filling in for some natural attrition.
tended by members in Gauteng,
Currently the membership stands at:
the Western Cape and KwaZulu-Natal.
tion in the form of booklets and training courses.
The legal liability workshop, in conjunc-
Minnaar concluded the regional meet-
tion with EOH and presented by Advocate
ing by reminding members to begin
G Augustyn, was also well received, as
preparations to enter the CMA Awards
was the rooftile workshop which was
for Excellence and look out for details
presented by Avenge Infraset, Monier
about the new-format awards.
there should be broader representation of CMA member activity in Precast, for example of roofing company members. Minnaar also discussed the structure of the CMA board of directors. Currently there is no-one with technical expertise on the board and he posed the question as to whether board membership should be extended to non-CMA members. Danie Hattingh suggested that the
COASTAL FEEDBACK MEETINGS
CMA change its constitution at the next AGM to allow external experts to join the board.
Coastal feedback meetings took place
ing longer than expected. Nevertheless,
in Cape Town, Durban and Port Eliza-
he said he expected the accreditation to
beth. Venues and refreshment for the
come through by the end of June.
During his presentation, Cockcroft spoke about achievements of the past year.
Cape Town and Durban meetings were sponsored by CMA members Afrisam
These included seminars and workshops.
and Corobrick respectively. As in Johan-
During the Cape Town meeting, Brian
He said the paving workshop given by Tony
nesburg, these meetings were presented
Cook of Concrete Units suggested that
McCormack had been particularly suc-
by CMA executive director Frans Minnaar
the CMA encourage all its members to
cessful, especially in Cape Town, which
and marketing manager Henry Cockroft
use the same standards system. Devi
was attended by 120 delegates. He at-
and included active participation from
Lategan of Lategan’s Sementwerke
tributed this achievement to the crucial
members who attended.
noted that SA is in a process of evolving
role played by Cape-based CMA members
Minnaar spoke about the financial
and that the government is pushing for
in encouraging attendance, especially of
status of the association and stressed
alternative construction materials and
that it is on a sound footing, despite the
methods. He said it is essential that
Cockcroft reiterated that CMA CS
fact that sponsorship is no longer be-
the CMA continues to promote precast
will have a hugely positive impact on the
ing received by cement producer PPC.
concrete and that cement producers be
association. He said the CMA CS mark
Revenue is now entirely driven by mem-
made aware of this.
is already appearing on precast concrete
bership fees and the CMA Certification
Danie Hattingh of Monier Coverland
products across the country and this
Services (CMA CS) mark of approval and
Cape Town asked for a breakdown of the
is helping to promote the CMA and its
distribution of the precast concrete
members as a precast elite. He added
There is a definite need for CMA CS
magazine, Precast, as he felt it was aimed
that the CMA is about to embark on skills
auditing and several members are now
mainly at senior management and did not
training, beginning with paving, for which
using the system. Minnaar stressed that
filter down to the middle management
there is the greatest demand. With this
CMA CS has not yet received SANAS ac-
and contractors in sufficient numbers.
in mind, the association is currently up-
creditation and that this process is tak-
Juliano Amodio of Marley Roofing felt
dating all its training material.
PRECAST | ISSUE TWO | 2017
Unfortunately, it seems, that SANAS
INDUSTRY NEWS 8
GETTING ROOFING RIGHT When it comes to roof tiling, the standard
use of them. Workshops such as these
excess heat in summer. Other modern
of installation does not always match the
presented by the CMA are a worthwhile
roof innovations, such as tile clips, metal
quality of the product. This can lead to
intervention and we hope to see more in
ridge trees and breathable roll underlays,
failures or inefficiencies of roofs’ drainage
future,” said Hattingh.
were also displayed as a means of simpli-
or insulation performance.
He also shed light on emerg-
fying installations and making them more
Knowledge is key in roof-
ing trends in the three main
ing and the CM A r e c en tl y
regions where the workshops
The workshop culminated in a talk by
embarked on a series of work-
were being offered, including
Craig Allen of new CMA member com-
shops hosted by some of the
Johannesburg, Cape Town and
pany Ecomatch on the recycling of roof
country’s top professionals to
Durban. Although dif ferent
and concrete waste products on site.
upskill architects, contractors
roofing materials such as steel
This innovation allows materials to be
and the roofing industry to
are still popular in these areas,
collected, processed and re-used on
share best practices for the installation
tiles have a distinct thermal advantage.
construction sites as fill materials or
of efficient roofing systems.
They also have an air flow, which is absent
First up, Danie Hattingh from CMA
in steel. He explained the thermal values
member company Monier Coverland
of roofs, R-values, SANS 10400 dealing
shared insights into an industry that
with roofs, how to install and test roofs,
has seen skills development almost grind
as well as the benefits of concrete roof
to a halt in the past few years. This has
tiles for climate control.
resulted in a pool of installers who have
Grant Uys of CMA member company
little or no formal training – and instal-
Aveng Infraset then demonstrated the
lation standards that are beginning
techniques discussed, including that of
to slide. “There are, however, private
dry-ridging. This technique is preferable
(Left): Danie Hattingh of Monier Coverland. (Above): Delegates across the country attended
training companies out for there and it’s in until the such installation energy-efficient Final material will not be supplied print/publication time as of approval is received. Please return faxtile to:workshops 086 509held 4850 the recent CMA roof in up to installation companies to make
roofing systems, as it is able to dissipate
ABSOLUTE INFRASTRUCTURE Sustainable urban drainage systems are increasingly being used to prevent run-off and flooding, and as a method of collecting and cleaning storm water. Whether heavy duty or light duty solutions are needed, Technicrete has the systems and expertise to create functional drainage and aesthetically pleasing kerb systems. Suitable for:
• • • • • • • •
Car parks Industrial Estates Retail Centres Pedestrian areas Domestic Drives Motorways Garages Service areas
• • •
Tongue & groove Standard grey or traffic calming colours Precast Various sizes available Highest quality
paving | mining | masonry | erosion protection retaining walls | drainage | kerbs | precast products www.technicrete.co.za Technicrete is a subsidiary of ISG, a leading supplier of innovative infrastructure products to the construction and mining markets in Southern Africa.
Tel: 011 674 6900 Maxi call: 0861 266 267
Q&A WITH THE CMA DIRECTOR Precast talks to Frans Minnaar, director of the CMA, about the implications of PPC’s cessation of its monthly sponsorship of that organisation Precast: Now that PPC has ended the
Obviously, now that the PPC sponsorship
monthly sponsorship to the CMA, where
has ended, there are more opportuni-
will the CMA obtain sufficient funds to
ties for companies – either members or
continue representing the precast con-
non-members – to sponsor promotional
events organised by the CMA for the
FM: Apart from sourcing sponsorship
benefit of the precast industry.
from other entities in the industry for promotion of precast concrete, the CMA
As a non-profit organisation, what percent-
also registered a new company, which
age of the funds raised for these events is
is a profitable one providing a “mark of
ploughed back into the precast industry?
approval” on the quality of precast prod-
As I’ve explained, the running of the CMA
ucts. This company is called CMA Certi-
NPC is funded with the membership fees
Companies can become involved in dif-
fication Services and, in compliance with
and sponsorships – such as the one we
ferent ways, such as providing venues,
the necessary requirements to obtain a
received from PPC – were utilised for the
sponsoring venues, sponsoring costs for
mark of approval, will issue the CMA CS
promotion of precast concrete products.
arranging presenters or providing lectur-
mark to a producer. This is a mark that
ers for workshops and training, obtaining
can be displayed on documentation or
How are the funds spent?
materials needed for these events, etc.
products, like the well-known SABS mark.
The CMA is organising different events such
These events are announced in advance
Since the CMA NPC is a non-profitable
as seminars, workshops, expos, industry
to the industry through different data-
company, the funds generated by CMA
meetings, technical committees, technical
bases, websites and cold calling.
Certification Services will be used to fund
workgroups, technical support, websites,
the CMA NPC in the future.
Facebook, etc, where the fundings raised
Since cement is a key ingredient in con-
through sponsorships are used.
crete, it made perfect sense for a cement
How were PPC funds used in the past
producer to sponsor events and be guar-
and what role did these play in developing
What events are earmarked for the rest
anteed of a high return on their investment
of the year?
through branding efforts. Surely the same
The PPC sponsorship money benefited
During this financial year, dif ferent
branding proposition is present for suppli-
the CMA members in that it was used for
events are planned, such as a rooftile
ers of other materials and services?
the promotion of precast concrete prod-
installation workshop, a legal liability
That’s 100% correct: it’s not only the ce-
ucts, as well as ensuring that the CMA
seminar, a concrete pipes and culvert
ment producers that could benefit from
had some back-up money for promotion of
seminar, a concrete masonry seminar,
sponsorships of these events. There are
precast concrete when sponsorships are
development of a registered training
numerous manufacturers of equipment
difficult to obtain in bad economic times.
course for paving installation, the re-
used in the precast industry, chemical
The PPC sponsorship was only utilised for
view of installation manuals for different
additives and admixture manufacturers,
this purpose, since the membership fees
products such as paving, roof tiles, pipes
retailers of precast products, associa-
of CMA members were used for funding
and culverts, and participation in the new
tions and institutions, etc.
the running of the business.
Concrete Conference that’s taking place in August this year.
What are the costs? The costs are determined by the type of
With the important role that this type of funding played in the many events hosted
How can companies become involved
event, where it will be arranged (through-
by the CMA, what opportunities exist for
in making these events successful and
out the country), how many sponsors
others to become involved and sponsor
how can sponsorship opportunities be
are involved, what type of audience is
targeted, etc. To determine what costs are involved or could be sponsored, it’s necessary to contact the CMA and discuss the possibilities. Who should be contacted there? Contact the CMA head office on tel: 011 805 6742 or the marketing manager, Henry Cockcroft, on tel: 011 805 6742 or 081 721 7701, or email: marketing@ cma.org.za.
PRECAST | ISSUE TWO | 2017
IF YOU THINK PRECAST CONCRETE,
THINK CMA PRODUCER MEMBERS.
AT I O N
y c a s t in c o
Address: Office 0400, Standard Plaza Building, 440 Hilda Street, Hatfield, Pretoria, 0083 Tel: (011) 805 6742 • Email: email@example.com • Website: www.cma.org.za
CATCH US ONLINE Precast magazine has gone digital with the introduction of an all-new website and online page-flip magazine. The digital site supports our growing print footprint and gives those interested in the subject of precast concrete in Southern Africa the chance to access the magazine, no matter where they are in the world. The www.precastmag.co.za website also gives visitors comprehensive information about the publication, contacts and details of all involved in the compilation and production of the magazine, as well as advertising and subscription information. For tech-savvy readers who prefer digesting their concrete news digitally, the page-flip version of the magazine allows them to access and page through the magazine from multiple platforms, including PC, Android and Apple devices. Another clever feature of the site is the listing of advertisers, which includes details and contact information for quick and easy reference, should a reader want to contact them. Andrew Meyer, CEO of Isikhova, the publisher of Precast magazine, says the decision to go online is aimed at giving readers the choice of receiving the publication in the format they prefer. “These days we have options and it’s our intention to give readers the news they want, the way they want it, when they want it.”
WARNING: ACT ON NON-PAYMENT Non-payment and late payment of accounts in the construction industry are becoming more of a problem as customers feel the pinch of SA’s credit downgrade and the resultant unease in the overall economy. Frans Minnaar, executive director of the Concrete Manufacturers’ Association, says the risk of non-payment is set to increase as credit costs escalate because of worsening lending conditions. “Rising interest rates can have a real effect on affordability of credit and this may lead to difficulty for some in repaying debts. As most contractors make use of finance to undertake their projects, the rising cost of credit may also lead to reduced overall profit for them, which in turn affects affordability of products and the ability to pay suppliers,” says Minnaar. “Non-payment or late payment is therefore a real risk and concrete manufacturers should take the necessary precautions to ensure customers are able to pay. They should also be proactive and ensure that all contractual dispute procedures, guarantees, etc are in place before supplying products. “Even big municipal and government projects may run into affordability problems in future, so it’s wise to ensure that all the necessary precautions have been taken before commencing supply of products. Manufacturers shouldn’t be afraid to exercise their rights and be prepared to lose the contract, rather than supply products for which they may never be paid.”
PRECAST | ISSUE TWO | 2017
(Bottom left and left): Side-of-the-road block-makers do not produce the required quality of blocks due to inferior mixing and moulding techniques, as well as poor material selection and curing regimes. (Below): Some of the symptoms home-owners can expect when buying side-of-the-road concrete blocks to do renovations.
CHEAP BUILDING BLOCKS CAN COST LIVES The price of buying crudely manufactured
average that allows for quality blocks
exists in the industry today. This is
roadside concrete (masonry) buildings
to be manufactured. The consequence
threatening a similar fate for others
blocks may be higher than consumers
is that only roadside manufacturers
throughout the rest of the country. The
think, especially in the event of a struc-
using manually operated equipment and
bad news for consumers is that the de-
ture collapse where damage is caused to
the cheapest raw materials are able to
mise of specialised, formal block manufac-
properties – or, worse still, if lives are
survive and produce inconsistent quality
turing capabilities will have the inevitable
lost as a result.
consequence of a demise in the quality of
T he unf or tunate consequence of
This type of practice has already led
consumers seeking the lowest cost of
to the complete collapse of the concrete
building materials is that prices have
block manufacturing industry in Gauteng,
plunged far beyond the sustainable
where not a single large-scale producer
According to Frans Minnaar, executive
“Consumers need to know that the only other way of selling a block much cheaper than mainstream manufacturers is cutting on the input costs.”
new houses and structures built.
director of the Concrete Manufacturers’ Association NPC (CMA), there is a vast difference between professionally batched and mixed concrete using goodquality materials versus roadside mixes. In addition, the equipment used to manufacture bricks in accredited factories is designed to properly batch, mix, vibrate and remove air pockets from moulds and precisely compact the concrete within closely set parameters. By comparison, hand-mixed concrete is much less precise and can vary by as much as 50% per block. This means that strengths are usually inconsistent and fall far short of specified quality standards. “Even in the toughest economic circumstances, it doesn’t pay to build critical structures out of inferior products – it simply isn’t worth the investment,” says Minnaar. “What’s the use of building on a fancy new lounge or bedroom at a considerable cost, only to find that the structure fails in a year or two and the walls begin to crack or seep water and eventually fall over? My guess is that if a home-owner
PRECAST | ISSUE TWO | 2017
wages. This sets the price within ap-
ing to fail, they wouldn’t buy them in the
proximately a 10% range of similar quality
first place – no matter how cheap they
blocks, with the only viable way of making
more money being to sell more blocks.
that the only other way of selling a block
He explains that all manufacturers follow
much cheaper than mainstream manu-
a similar formula and have similar input
facturers is cutting on the input costs
costs that determine the price of blocks.
by using inadequate equipment, either
This includes the cost of cement, sand
reducing the quality of sand and stone,
and stone used in the mix. Capital costs
or reducing the amount of cement used
of decent equipment need to be factored
in the mix and paying workers an unfair,
in, as does the cost of labour and decent
knew upfront that the blocks were go-
Consumers therefore need to know
Unsuspecting buyers of these blocks
can expect the following problems with
“Perhaps there’s still a use for roadside
blocks in the building of rural low-wall
• Severe structural cracking.
traditional dwellings, where mud and
• Straight-line cracking through blocks
cow manure was used previously, as they
vertically and horizontally.
provide similar strength characteristics.
• Shrinkage cracking of blocks.
But in formal housing, there’s no place
• Inability to bear a load on the wall for
for these blocks and we strongly advise
everyday items such as roofs, gates,
consumers to stay away from buying
washing lines and carports.
these cheap alternatives,” says Minnaar.
• Crumbling sides and eventual collapse
PRECAST | ISSUE TWO | 2017
of blocks under load.
“When it comes to buying blocks for houses and walls, it pays to do research
• Wastage during the building process.
upfront to avoid problems. Speak to us
• Water seepage.
or visit our website and view the lists of
• Damp problems.
CMA members at: www.cma.org.za.”
GLOBAL VIEW 14
PRECAST PROVIDING ROADWAY SOLUTIONS GLOBALLY In places like India and the USA, engineers are working feverishly to develop precast concrete road solutions to overcome separate and distinct challenges in their own countries.
developed to provide mobility in many of
However, the solutions found abroad
the erosion of services and infrastructure.
the country’s crowded streets. Here, every last centimetre of space is occupied by traders or taken up by households. Without road infrastructure, these communities are at risk of becoming isolated, which can stifle development and lead to
may have particular applications in SA that can either be redeveloped for local
conditions or taken as part of a solution
However, the problem in many of these
towards developing much-needed road
areas is that heavy equipment such as
infrastructure – and even to overcome
graders and rollers simply cannot trav-
the maintenance backlog that has for so
erse the lanes and alleyways to get there.
immediately af ter being laid. T hese
long dogged our roadways.
In addition, many of the roads earmarked
solutions employ traditional brick and
In India, studies show that the use of
for paving are themselves too narrow to
block-type precast concrete pavers,
precast concrete for roadways is being
allow traditional road-building equipment
as well as new methods that employ
to work effectively. Other in-situ methods
fibre-reinforced concrete moulded to
have similar shortcomings, mainly due to
various shapes and sizes, depending on
space or lack of support networks, while
“Without road infrastructure, rural communities are at risk of becoming isolated.”
still others fail due to premature usage in these crowded areas.
Where areas are fairly undulating due to lack of compaction and road-making
To overcome this Catch-22, Indian
equipment, the road can still be paved
authorities are pursuing solutions to
using manual labour and pavers which
build precast roads that can be deployed
are specially made to suit the terrain.
comparatively rapidly and be used almost
These can be moulded and adapted to the
PRECAST | ISSUE TWO | 2017
the concrete elements will also reduce as
flexure. These pavers are relatively easy
work can be performed off-site at the
to produce in mechanically cast plants
precaster’s facility. Secondly, the period
They can be almost free of shrinkage
for which the lane is out of service can
and cracking and are more robust in the
be scheduled to off-peak traffic hours,
handling and placement process.
because construction can take place at
What is more, the precast concrete is durable and maintains its structure
roads get longer and demand for products increases. In addition, the precast concrete is manufactured under controlled environments, which leads to increased durability and lower maintenance costs. The study shows that precast concrete solves traffic mitigation problems on three fronts. Firstly, total time to complete the project is kept to a minimum, because the majority of the
night and the repaired area can be opened to traffic for the morning rush.
better than other road types in harsh environments. In parts of India, roads
may be subject to prolonged wet periods
Finally, the construction footprint is kept
of monsoon-type rainfall, followed by
to a minimum. PCPSs require only a sin-
extended dry cycles. Precast roadways
gle lane to be closed on two-lane roads,
tested under these conditions have
including the shoulder. When there are
remained operational throughout these
more lanes and an interior lane needs
cycles, with little impact on the struc-
work, the interior lane and an adjacent
ture of the roadway.
lane need to be closed to safely accom-
Studies also found that wear surfaces
modate equipment and workers. In either
under all conditions were good and roads
case, traffic can continue to flow while
lasted for many years without signifi-
the repair is underway.
cant deterioration. This suggests that
The other advantage of using PCPSs
precast is a suitable solution for dense
is precast concrete’s proven durability.
urban areas and can withstand harsh
PCPSs are designed to last, with the
conditions. But how do they stand up
same criteria as new roller-compacted
to the challenges of large, high-volume
concrete construction that has an ex-
roadways with faster speeds?
pected lifespan of over 50 years. The material’s precision and quality are de-
rived from the plant-controlled conditions
In the USA, precast concrete road sur-
of the precast facility. Internal quality-
faces are being manufactured and tested
control inspection and testing ensure
precisely for these types of conditions.
a high-quality product. Furthermore,
The challenge in the USA is mainly due to
a quality product is achieved through
massive traffic volumes that make lane
inspection of the precasting process
or entire road closures difficult, if not
and field testing of the installed product.
impossible. As a result, the solutions be-
SA, with its increasingly congested
ing sought are centred around the speed
roadways, can learn from these stud-
lie of the ground if it is uneven. Larger
of manufacture of roads, using large
ies. In dense urban settlements, the
pavers (or even panels) have the ability
precast slabs to reduce road closure
use of bricks and pavers can provide a
to cover more ground and are therefore
times. Simultaneously, there is a need
long-lasting, low-maintenance solution
quicker to construct with less effort,
to reduce maintenance requirements,
to uplift communities and connect them
but require even terrain and reasonably
which may also affect traffic.
with transport nodes and centres. Like-
Studies at the School of Civil Engineer-
wise, large cities like Johannesburg and
ing Purdue University found that although
Cape Town can ill afford traffic conges-
the precast slab or panel methods being
tion and the benefits of precast concrete
T he use of fibre-reinforced cement
employed at present have a higher con-
roads are many. Perhaps it is time for
helps to prevent cracking under high-
struction cost, they offer the advantages
our municipalities and road authorities
moving traffic volumes and gives the
of speedy laying, which results in less
to start engaging with the CMA and its
concrete better compressive and impact
traffic congestion and fewer delays, as
members to find precast solutions for all
strengths, while also allowing a level of
well as lower user costs. The costs of
PRECAST | ISSUE TWO | 2017
“Precast concrete is manufactured under controlled environments, which leads to increased durability.”
No matter what the job, our range of cement products will give you the quality you need for your build. Want to know more? Call us on 0800 CEMENT (236 368) or visit www.ppc.co.za
duced a fresh design option for landscape architects and paving contractors with the launch of Santigo, a new paving block produced in an attractive textured finish. Aveng Infraset Landscape Products
NEW PAVING BLOCK LAUNCHED
sales manager, Brennan Small, says
rumbled finishes for added visual and
Santigo complies with current trends
design diversity,” advises Small.
“In addition, we produce paving blocks, kerbing and retaining wall blocks in
in landscape design, which favour larger,
Requiring only 17 blocks per square
our Masa plant, which is also located
more cost-effective pavers and is ideal
metre, the 240 x 240 x 50mm block is
at Rossway. Both Columbia and Masa
for shopping and community centres,
easy and cost-effective to install. An
manufacture state-of-the-art plant and
retirement villages, patios, driveways,
added advantage is that the blocks are
equipment which enable us to introduce
walkways and pool surrounds.
manufactured with bevelled edges on one
new and, in many instances, unique prod-
“Santigo has been designed to be laid
side and straight edges on the other. As
uct options for landscape architects and
in conjunction with our Masonique and
they are cast in body-through colours,
other construction professionals.
Cottage Stone pavers, thereby creat-
they can be laid either way, ie they are
ing greater scope for attractive design
“Our Masa plant includes steel production pallets for enhanced vibration
and layout options. These would typically
“Santigo is a high-quality product
transference, in-line washing and seal-
comprise a Santigo body combined with
which complies with SANS 1058:2012.
ing, ageing and waving techniques and
either Masonique or Cottage Stone, or
It’s cast to high tolerances at Aveng
a specially insulated curing chamber. It
both, as borders/header courses.
Infraset’s Columbia plant at Rossway,
also boasts an advanced colour blending
“Santigo is available in three of f-
Centurion, using a vertical manufacturing
facility which is faster and more accu-
the-shelf body-through colours – grey,
process which guarantees that it’s free
rate than earlier-generation blenders,”
charcoal and Sahara – in addition to
of any highs and lows. Moreover, its tex-
numerous other colour options and can
tured finish ensures that it’s non-slippery
also be ordered in bush-hammered and
when wet,” says Small.
(Above): Santigo is a new paving block produced by Aveng Infraset with an attractive textured finish.
DEMOULDING MADE EASIER CMA member Chryso has launched a com-
little odour. The range even includes a
plete range of technologically advanced
vegetable-based, environmentally friendly
releasing agents for use in the construc-
release agent which is biodegradable and
tion and precast concrete industries.
non-toxic, making it safe to use in confined
According to Hannes Engelbrecht,
applications such as mining and tunneling,
general manager: inland at Chryso South-
or any other poorly ventilated area.
ern Africa, getting the best results requires choosing the appropriate release
agent, as there are specific formulations
Reducing blow holes is also possible, with
for all options, including timber formwork,
low-viscosity oil lowering the surface (Above): Releasing agents are a valuable part of any construction project, ensuring that concrete does not stick to formwork or moulds.
tension against the sides of moulds
(Below): Hannes Engelbrecht, general manager: inland at Chryso Southern Africa.
is designed for dry precast spun pipe
says Engelbrecht, “as the cost is rela-
quality of the Chryso Dem range ensures
release of dry concretes which have been
tively low, compared with the value of
that there’s no adverse effect on the
exposed to the high temperatures of
the formwork or mould. The Chryso Dem
adhesion of subsequent finishes and
steam-curing. Others are mineral-based
range ensures easy, clean release of the
coatings,” says Engelbrecht. “This allows
release agents suitable for all types of
formwork or mould from the concrete,
plaster, paint or other coatings to
without damaging either.”
be applied to the concrete with no
“The Chryso Dem range is a
associated problems; the release
fundamental change for an industry
agents are also water-repellent, so
accustomed to a one-size-fits-all
The products reduce the likelihood of any
they aren’t affected by rain.”
man-made formwork and decorative concrete, as well as wet or dry precast. “It’s false economy to simply use the cheapest releasing agent available,”
imperfections and surface damage to the
These products do not have any
and allowing air bubbles to escape. It production, with the added benefit of the
formwork on site.
approach when it comes to release agents,” says Engelbrecht.
concrete, such as blow holes, creating
negative effect on the hydra-
more durable and attractive concrete
tion of concrete as it cures
among user s, who’ll
and they are inoffensive to
now start expecting
apply, as they have very
“It’s important to remember that the
PRECAST | ISSUE TWO | 2017
“It’s also raising the bar
CMA member Aveng Infraset has intro-
BIRKENMAYER EIRICH ANNOUNCES HB RANGE OF CONCRETE MASONRY MANUFACTURING MACHINES
CMA member H Birkenmayer started impor ting V ibr o Block brick-mak ing machines from Germany in 1955 and exhibited a small Vibro Block machine at the Rand Easter Show of that year. Such was the success of these machines that it soon afterwards obtained permission to manufacture locally. Thus, the VB brand was established
tinue the VB logo, replacing it with HB,
in the VB1 machine, followed soon after
identifying its machines more closely with
by the VB2 â€“ and in the 1970s, the VB4.
H Birkenmayer. Thus, the HB14, HB20,
Subsequently, the VB machines were
HB33, HB48 and HB68 now comprise a
copied by other manufacturers and these
comprehensive range of machines to suit
machines also carried the VB designation.
Over the years, this has caused a great
Over the past decade, upgrades to the
deal of confusion in the marketplace,
previous machine designs have been ongo-
with many customers believing that the
ing, mostly driven by developments and
copied machines were actually Birken-
performance offered in the more costly
imported machines, but always mindful
Imitation might well be the sincerest
of the necessity to relate closely to the
form of flattery, but it can be a problem
requirements of the local market and,
commercially. In 2005, the management
indeed, many others less sophisticated
team at Birkenmayer decided to discon-
than those of Europe and North America. The recent acquisition of 100% of H Birkenmayer by the worldwide Eirich
PRECAST | ISSUE TWO | 2017
or projected future expectations.
Group is the latest turn of fortune in
While the HB68, for instance, can be
an already eventful 65-year history. The
offered with unique tamper locking, so-
latest HB68 machine is manufactured
phisticated feed box features, any pallet
specifically to customer requirements;
and product size capability and advanced
this model offers many of the features
electronics, the fundamental machine is
of imported machines, while retaining the
the solid VB6, so well-accepted in the
original Vibro Block philosophies which
marketplace and still built to the exacting
have contributed to the quality Birken-
Vibro Block policy of Quality First.
mayer customers have learnt to expect.
Pairing with the popular Eirich In-
In keeping with the Eirich Group policy,
tensive mixer RV19, this combination
customer requirements come first. Ma-
offers an incomparable performance and
chines are offered to suit the application,
ZIMBABWE PIPE MANUFACTURER UPGRADES EQUIPMENT
to market through the company’s own
”It assisted in the design of the batch-
The commissioning of a new high-tech
fleet of trucks and delivered directly to
ing plant, the design of the building, the
pipe and manhole ring plant in Harare is
logistics inside the building, as well as
Since commissioning, the plant has met all production requirements and produced the new range of products, which dovetail perfectly with the company’s range of existing products and services. These include the manufacture, supply and support of a wide range of precast
of information in the design phase of the
concrete products, which are brought
ensuring that technologically advanced,
The company is also able to provide
the outside logistics around incoming
high-quality products are available in
high-level technical advice in support
materials and outgoing products. The co-
Zimbabwe’s capital city.
of the products, as well as providing
operation with HawkeyePedershaab has
Acsend Concrete’s investment in a
skilled manpower to ensure products are
given me a state-of-the-art production
VIHY Multicast SCV 120 production plant
installed correctly on site. “Since instal-
plant that can supply current demand
from CMA member HawkeyePedershaab
lation, our new machine has significantly
and can easily be geared to supply future
enables the manufacturer to reliably
enhanced product quality and ensures
needs. I firmly believe that a dependable
produce a range of high-quality rings and
complete consistency with required
precast product has its roots deeply
short pipes for infrastructural projects
embedded in an equally reliable production
within the region. In keeping with market
“In addition, the VIHY Multicast SCV
demands for consistent quality, the new
120, with its unique vertical vibration
equipment also offers the best possible
system, gives us flexibility and versatility
production and material-efficiency for the
to introduce all-new products to the Zim-
manufacturer to produce cost-effective
babwean market – as seen on my tours
of Scandinavia. These will be introduced
According to Acsend Concrete owner and managing director, Antony Benesi, the
plant,” he says. (Top): Acsend Concrete managing director Antony Benesi. (Above): VIHY Multicast SCV 120 is a versatile vibration machine for the production of manholes and short pipes up to 1 200mm diameter.
in months to come, to add value to our local market,” says Benesi.
expansion project followed months of inves-
Plant description HawkeyePedershaab’s scope
tigation on his part as he travelled exten-
sively to study best practices and find the
He explains that Acsend Concrete and
– VIHY Multicast SCV 120.
most suitable equipment for his company’s
HawkeyePedershaab worked closely
– Mould equipment for
requirements. These travels culminated in
together throughout the whole pro-
Scandinavia, where he was inspired by local
ject. “I knew the HawkeyePedershaab
– Mould equipment for
producers who had embraced technology
service ethic and its machines from
from HawkeyePedershaab to produce
previous experience, so I had no doubt
– Automatic concrete batching
cost-effective and high-quality prod-
it could supply the equipment I needed.
ucts. This became the inspiration for the
But, equally important, it was a very
– Concrete laboratory equipment.
Harare-based plant’s upgrade.
valuable partner and an incredible source
450-1 200mm pipes, L=1,25m. 900-1 050mm manhole rings. and mixing plant.
PRECAST | ISSUE TWO | 2017
LONG-LASTING PAVERS In 1978, the Aggeneys mining township
“That was 39 years ago and the roads
was developed in the Northern Cape by
and houses are still in perfect condition,
the then Black Mountain Group. Housing
even though traffic throughput has been
and roadways were built for the group’s
at a far greater speed than the original
employees and local residents. Techni-
roadways were designed for,” says Tony
crete, then known as Concor Precast,
van der Berg, technical executive at the
operated two block manufacturing plants
21 (Above): Technicrete’s Olifantsfontein factory.
adjacent to Aggeneys, enabling it to
“We visited Aggeneys 15 years ago
produce the then newly-designed Zig-Zag
with engineers from the Black Mountain
gies and equipment in the manufacture of
block pavers for the project.
Group who confirmed that they’d con-
our Technicrete concrete products and
ducted no maintenance whatsoever since
these, too, will stand the test of time.
we supplied the new Zig-Zag product
Our expertise in concrete technology is
in 1978. We’d also originally supplied a
well documented not only for standard
number of black hollow products for the
products, but for customer-specific re-
housing project and, when visiting earlier
quirements as well,” says Van der Berg.
(Above): Manufacture of DZZ pavers.
this year, we found they still have a good
Since 1978, Technicrete has intro-
surface and appearance – testimony to
duced Double Zig-Zag (DZZ) interlocking
our manufacturing and design capabili-
pavers, which offer the same longevity
ties and a real commendation for the use
and cost-effectiveness through their
of concrete in order to obtain a longer
continuous, hard-wearing surface over-
lifespan for such applications.
lay. They are particularly suited for areas
“Originally, we manufactured our Zig-
of heavy traffic such as municipal parking
Zag product with a VB4-sized Schlosser
areas, petrol station forecourts, indus-
machine and a single Besser machine. To-
trial and factory roads, suburban streets
day we use far more advanced technolo-
and domestic driveways.
CASTLE BOTTOM KERB INNOVATION TROPHY WINNER - CMA AWARDS FOR EXCELLENCE 2016
Advantages of Castle Bottom Kerbs compared to conventional kerbs: 1. More load points help the Castle Bottom Kerb sink into the screed, creating much better adhesion in all directions. 2. Eliminates air pockets in the screed which could create weaknesses under the kerb after installation. Castle Bottom Kerb
www.bosun.co.za Tel 011 310 1176 firstname.lastname@example.org
ENGINEERED SOLUTIONS FOR SOUGHTAFTER LUXURY APARTMENTS Elematic South Africa’s (ESA’s) highquality precast hollow core concrete slabs and top-notch service on the Carlswald Luxury Apartments development in Midrand secured the company a good pipeline of work from the estate’s
(Above and right): The Carlswald Luxury Apartments used hollow core slabs from Elematic.
developer, Century Property Develop-
hall, a clubhouse, a swimming pool, braai
slabs were selected primarily because of
ments, going forward.
facilities, a tennis court with pavilion,
the speed they offer in comparison with
The Carlswald Luxury Apartments
children’s play areas, outdoor gyms,
cast-in-situ concrete slabs. Overall, the
project was no small undertaking. The
a skate park, a bird hide and a Spark
construction team was able to complete
470 units, configured in 86 blocks, were
School for the children of residents.
approximately 40 units a month on
developed and built in a single phase
ESA supplied all the precast hollow
average – an achievement which would
by Century Proper ty Developments
core concrete slabs for the project, sup-
not have been possible without careful
between May 2015 and October 2016.
plying about 55 000m2 in total. Hendry
planning, co-ordination and teamwork.
The development also includes a variety
Brand of Century Property Develop-
In that respect, Brand is highly com-
of amenities such as a multi-purpose
ments explains that precast hollow core
plimentary about the service Century
service and our working relationship,
tions and to value-engineer each project
ESA. “To begin with, there were a num-
we really do get the whole package from
with our clients,” notes Craig Webber,
ber of different designs that had to be
ESA,” he says.
director at ESA. “We also try to improve
catered for because of the various differ-
“We need a high-quality product be-
continually on what we’ve done before.”
ent apartment and block configurations.
cause we want longevity in our buildings,
This meeting of minds has resulted in
We used all the different thicknesses of
especially since they are for the rental
a good working relationship with Cen-
concrete slabs available – sometimes we
market. At the same time, we also need
tury Property Developments, which has
even used them all on a single floor,” he
awarded ESA a number of other con-
notes. He goes on to say that even before
tracts subsequent to this one. “There
the project broke ground, the Century
are benefits to working with the same
Property Developments team, including
contractors and suppliers if we can,” com-
its in-house architects, sat with the ESA
ments Brand. “The ESA team know what
team to look at ways of optimising the
questions to ask, they know how we work
structures for economies of scale, and
and they’re extremely thorough. Like us,
to value-engineer for cost-effectiveness.
they take pride in their work. We also find
“We worked well together because we
that working with people we know means
both like precision, and we like to have
we don’t have to go through a process of
things well planned out in advance,” he
trial and error with a new contractor for
every project, because that can result in
There was an ESA team on site al-
to find ways of optimising our costs,
most constantly for the duration of the
which can escalate quickly on a project
The Carlswald Luxury Apartments
project, measuring up and installing the
of this size,” he continues. ESA’s willing-
development has certainly been a suc-
slabs, which were on the critical path for
ness to explore options with the client,
cess, with only a few units left to let at
project completion. Brand reports that
while maintaining high attention to detail
the time of writing. With one-, two- and
Century Property Developments has
and not compromising on product quality,
three-bedroom apartments available,
been very pleased with both the quality
helped ensure the successful delivery of
ranging from 53-113m 2, these luxury
of the slabs and the service received
Carlswald Luxury Apartments.
rental units in a secure lifestyle estate
from ESA. “In terms of price, quality,
V I H Y
Property Development received from
“We make every effort to explore op-
have become extremely popular.
M a s t e r f l e x
The Masterflex machine is an allround machine for the production of concrete pipes as well as concrete manholes
• All-round machine for vertical cast concrete pipes and manholes • Easy to operate • VIHY core vibration for maximum compaction and rugged performance • Automatic production cycle giving high output with minimum amount of labor • No overhead crane required and no specific requirements for building • 24/7 after sales and service programme for every customer proud member of CMA
PRECAST | ISSUE TWO | 2017
European Headquarters Saltumvej 25 9700 Bronderslev Denmark
North American Headquarters 506 S. Wapello St. Mediapolis, Iowa 52637 USA
12M-HIGH RETAINING WALL SYSTEM BUILT WITH SPECIALIST GEOTECHNICAL ENGINEERING Limited space and precipitous slopes
with 300kN tie-back anchorages and con-
called for specialist geotechnical engi-
crete waler beams. Geofabric reinforce-
neering in the construction of some of
ment was not an option in this instance,
the concrete block wall structures in
due to the space between the retaining
Bakoven on Cape Town’s Atlantic sea-
wall block facing and the embankment
board. The walls were built to retain a
face being only 300mm. Steel-reinforced,
the backyard walls is 12,4m. The lower
steep granite embankment which was
the waler beams measured 350mm thick
wall is the highest, at 5,6m. The middle
cut to create a building platform for the
and about 1 000mm high. They were
wall tops 3,7m and the upper wall 3,1m.
construction of a luxury six-storey apart-
constructed on the upper and lower wall
Each of the three main walls was built at
ment block offering spectacular views
sections and spanned the full width of
an angle of 75˚. There are two narrow
of the Atlantic and the Twelve Apostles
the embankment face.
terraces between the lower and middle
Further reinforcement was achieved
wall and the middle and upper wall.
Apar t from the sea-facing front
by filling the blockwork in the lower half
A sophisticated sub-surface drain-
elevation, the remainder of the building
of each of the three main concrete block
age system was built into the design to
is enveloped in a cocoon-like concrete
walls with steel-reinforced concrete.
handle the percolation of water from the
block wall structure of varying heights
Free-draining sand was used to fill the
slope and to prevent the build-up of pore
and angles. The walls were designed by
space between the blocks and the em-
pressure. In addition, rainwater flowing
structural engineer, Fred Laker, with
bankment. The total combined height of
off the mountain slope is captured in a
geotechnical engineering input from
stone-filled trapezoidal concrete channel
Kantey & Templer Consulting Engineers
which drains away from the wall into the
on the principal retaining components
stormwater drainage system. Perforated
at the rear of the property. All the walls
100mm pipes were installed at the bot-
were built by Dassenberg Retaining using
tom of the fill material behind each wall.
L12 retaining wall blocks supplied by CMA
These drain into core drain pipes (gulleys)
which, in turn, drain into stormwater
Geotechnical site inspections and
pipes. The stormwater pipes run under
a detailed slope stability analysis con-
the building and drain into a silt trap, which
ducted by Kantey & Templer revealed
then flows into municipal drainage.
that the bulk of the materials exposed
Fire escape staircases on each side
in the cut face took the form of deeply
of the property were built as part of the
weathered granites. It was determined
retaining wall structures using Terra-
that if left unsupported, parts of the
force’s 4x4 Step blocks.
embankment could be prone to instability during periods of high rainfall. Following an assessment of various support options, Kantey & Templer recommended that two of the three main rear concrete block walls be provided
PRECAST | ISSUE TWO | 2017
(Top): Terraced concrete block walls built with Terraforce L12 blocks. (Above): Tie-back anchorage on the upper waler beam. (Left): One of the fire escape staircases built with Terraforce 4x4 Step blocks.
BASICS OF PAVING Manufacturers can play a role by raising awareness and sharing the basics of paving with installers who buy their products. The following article is based on the official SANS 1200MJ standards for paving installation in SA. The aim is to explain the flexible installation of segmented block paving in simple language to share with customers and installers of precast concrete pavers. All too often paving projects fail because
the earth after excavation. If a plate
of poor installation, rather than the qual-
compactor is used, ensure its weight
ity of the pavers used. Sadly, manufac-
is at least 75kg.
turers’ reputations are on the line and
• Install a sub-base of 150mm with G5
can be incorrectly tarnished in the event
of a failure.
• Compact the sub-base with a roller
or similar material.
“Many paving failures occur due to ingress of water into the earthworks beneath the paving.”
It is worth noting that the entire pro-
or plate compactor weighing at least
cess – from initial earthworks, levelling
75kg. Compacting passes will be
and compaction to the design of various
determined by the type of machine
under-courses, pavers and finishes –
and its weight. Various passes should
tations or construct falls. Remember,
requires meticulous attention to detail
a fall of 2% is recommended in one di-
and needs to be done correctly to ensure
• Do not attempt to compact layers
rection (transverse) and 1% in another
the overall success of the project.
thicker than 150mm. It will not com-
Also, paving should further be laid
• The sub-base is the foundation layer
proud of (ie 5-10mm higher than) drains
For commercial projects, bulk earth-
of the paving. It should be smooth,
or channels and sub-soil drainage needs
works are generally done by the main
level and the correct falls should be
to be installed when there is evidence of
contractor, while the laying of paving is
achieved with this material.
high levels of underground water. Drain-
left for a specialised paving contractor.
• Do not install plastic sheeting beneath
age channels and underground drainage
However, where earthworks are not
paving. Plastic sheets negatively
pipes should be installed in certain areas
done by a specialised contractor, the
affect the structural integrity of pav-
like low points in steep driveways, around
following sub-base and soil preparation
ing. They also do not prevent the
downpipes, etc. Carefully consider the
should be done:
growth of weed, as these grow from
natural land, walls and buildings when
• Set out the area to be paved and
the top and not through the paving.
designing a drainage plan.
excavate to a depth of approximately
250mm. (This should allow for a sub-
base of 150mm, together with the
Consider drainage carefully. Many pav-
Pavers are fragile. They could chip and
thickness of pavers and bedding mate-
ing failures occur due to ingress of
break, if not handled with care.
water into the earthworks beneath
• Move pavers by means of special paver
• All tree roots and other plant matter
the paving. Construct the necessary
carts or pack them in wheelbarrows
gradients in your foundation layer and
and unpack them one by one.
do not use bedding sand to fill up inden-
• Never throw pavers in wheelbarrows
should be removed.
• Preferably use a roller to compact
PRECAST | ISSUE TWO | 2017
or front-end loaders and tip them at
sible. Ensure that the concrete beds
• Creating edge restraints by digging
also retain the layers underneath the
a little trench on an edge after paving
• There will be slight variances in colour
paving. Therefore, bed-edge course
has been installed, then filling it with
between different batches and even
pavers on 75mm-thick concrete and
in-situ concrete and trowelling it down
packs of paving from any paving manu-
haunch at least half their height at
will definitely fail within a few months.
facturer anywhere in the world. It is
the back of the paver with concrete
therefore advisable to draw and install
at least 75mm wide. This will create a
pavers from different packs during
solid concrete block that will not move.
• Well-draining sand containing no clay
installation to avoid a patchy finish.
• Use a moist concrete mix of four
and very little fines should be used for
parts sand, two parts stone and one
part cement to construct the bedding
• Please see the grading analysis for
Edge restraints prevent pavers from
and haunching of edge courses.
creeping. When pavers move horizontally,
• Experience has shown that the best
1200MJ (Table 1.1).
grouting material between them can be
edge restraints are kerbs. For resi-
• Do not mix cement with bedding sand,
lost and the paved area will fail completely.
dential and pedestrian applications,
• Edge restraints should preferably be
garden kerbs are suitable. Kerbs
• Bedding sand should be moist (not
installed before the paving.
bedding sand as specified by SANS
unless specified by an engineer.
should be bedded and haunched in
saturated with water) when bedding
• The earth preparation should extend
the same way as edge course pavers,
pavers. The sand should contain 4-8%
to the rear face (outer side) of edge
• On large paved areas and paving on
Tip: If you squeeze a handful of sand, it
• Edge restraints could be kerbs or
steep slopes, additional restraints
should compact to a ball, but no water
in the form of edge beams might be
should escape between your fingers.
• Bed-edge restraints in concrete and
required. Please refer to the CMA
• The sand bed must be laid slightly in
guidelines for steep slopes.
pavers/copings bedded in concrete. haunch them with concrete, if pos-
PRECAST | ISSUE TWO | 2017
advance of the placement of the units,
but only to the extent that the par-
that compaction should be done at
pavers, which prevents sagging and creep-
ticular area of paving can be com-
least once a day and more often when
ing. It also distributes loads to the layers
pleted within hours on the same day.
it is very hot.
With the sun baking down, it should be
• A plate compactor should be used,
• Jointing sand must pass a 1,18mm
limited to a few hours at a time and
but it is recommended that a piece of
sieve and should contain 10-50%
its moisture content should be con-
rubber conveyor belting or special
material that passes a 0,075mm sieve.
tinuously assessed on site.
cover be attached to the base when
• Plaster sand is generally used for
• When bedding sand becomes dry, it
installing pavers with special surface
should be raked back into a heap,
moistened and spread out again.
Do not lay conveyor belting on the pav-
paving grouting in inland areas.
Tip: Use light-coloured plaster sand rather than red sand. Red plaster sand might
ers and compact on it, as this will absorb
stain your paving.
Nominal sieve size (mm)
the forces and pavers will not compact
• Sand must be bone-dry and swept
• A roller could also be used to achieve
• Sweep diagonally across pavers and
levelling. Ensure the roller’s vibration
is switched off when this method is
• Go back and forth until all joints are
• Check and straighten lines and remove
• Do not use water to wash in sand
damaged pavers after the first plate
compaction. Use an alignment tool in
• Do not use a mixture of dry sand and
order to align and “tighten” pavers.
cement and then sprinkle water on it
• Do not compact closer than 1m of any
to hydrate. The cement left on pavers
will stain the pavers.
not along the “lines”. completely filled. between the pavers.
• Temporary edge restraints should be
• The CMA advises against using a
NB: The principle is to ensure you lay
used across the front laying edge
cement slurry to sweep into joints
pavers on a bed of moist sand. Moist
when installation is to be continued
between pavers. It might stain your
bedding sand will allow pavers to “bed in”.
the following day.
pavers and cause picture framing,
This is crucial to create a smooth, even
Tip: When this happens, remove the first
where pavers absorb moisture from
two or three rows of pavers when you
the slurry. This phenomenon creates
• Bedding sand should be 25-35mm in
start the next morning and re-pack. These
permanent white stains on the border
its compacted state. To achieve this,
pavers will have moved during the night,
of the pavers.
it should be screeded to a thickness
opening larger gaps than required.
of 30-40mm, which will then compact
to the correct thickness once pavers
Vibrate sand on pavers in order to com-
Precision cutting ensures a neat instal-
pletely fill joints between the pavers.
• Bedding sand should be screeded with
lation without movement and the loss of
• Use a large plate compactor with a
a straight edge (like a straight plank
rubber mat fixed to the base plate,
or similar), using rails in order to
• Whole units must be laid first. Pre-
achieve the correct thickness.
cisely cut pieces should then be fit-
• Alternatively, use a roller with vibra-
The CMA does not recommend screed-
ted into gaps which are too small to
ing freehand in a circular motion, with-
lay complete pavers in, such as those
• Sweep more sand into the joints as
tion switched off.
which are close to edges and around
sand settles in them.
Critical maintenance: Sweep additional
Laying and setting out
• Mark and cut one paver at a time
sand into the paving joints after two weeks,
• Lines must be set up at right angles
using a block cutter. An angle grinder
two months and thereafter as needed, or at
to each other to control the alignment
or masonry saw with diamond-tipped
least once a year before the rainy season.
of the pavers.
blades can also be used.
• In areas with a high risk of sand wash-
• Align paving in a right angle with buildings.
• Do not use tiny cut pieces. Rather
• Joint widths of flexible installed pavers
use a 2 /3 and ½ paver in combination
• P a v er s sh o ul d n o t b e r em o v e d /
ing out, grouting sand could be stabilised.
instead of a full paver and a small bit,
replaced once jointing sand and the
• Most pavers in SA have spacer nibs
final compaction have been done.
• Do not cut on paving already installed.
must be 2-6mm. to act as spacing guides when installing.
Fine concrete dust caused by cutting
will cause stains.
Because there are minerals and moisture
The first compaction levels the pavers.
• Always wear a dust mask, gloves and
in the soil and material we use to manu-
• Compact pavers in sections once they
facture pavers, paving might be affected
goggles. Do not cut near other people.
by efflorescence in its lifetime. It is a
• Bedding sand must be moist when the
natural, phenomenon which will disappear
Jointing sand creates interlock between
compaction takes place. This means
PRECAST | ISSUE TWO | 2017
MAKING SAFETY A PRIORITY Health and safety representatives in the concrete manufacturing industry are not a luxury. Rather, every company employing more than 20 staff must appoint one, in strict accordance with the law. In this, the fourth in a series of articles focusing on safety matters affecting the concrete manufacturing industry, well-known veteran health and safety expert, Oom Callie Calitz of OHS Consultants, looks at the appointment of health and safety representatives and their function in the workplace. According to the law, every employer
(e) Facilities, training and assistance that
who has more than 20 employees in his
employment at any workplace
must be provided to a health and safety representative.
All the activities in connection with the designation, functions and training of health and safety representatives
shall, within f our months
Provided that there is no
shall be performed during ordinary work-
after commencing business,
registered trade union, the
ing hours, and any time reasonably spent
or from such time as the
employer shall consult with
by an employee in this regard shall for
number of employees exceeds
the employee representa-
all purposes be deemed to be time
20, designate a health and
tives in order to conclude an
spent by him in carrying out his duties
safety representative for a
as an employee.
workplace, or for different
Duties and care
Only those employees em-
(A) A health and safety representative
specific period of time for the
Negotiations and consultation before
ployed in a full-time capacity at a specific
may perform the following functions in
designation of health and safety repre-
workplace, and who are acquainted with
respect of the workplace or section
conditions and activities in that workplace
of the workplace for which he has been
(1) The employer shall, in any workplace
or section thereof, shall be eligible for
where there must be a health and
designation as health and safety repre-
(1) Review the effectiveness of health and
safety representative, meet with the
sentatives for that workplace or section.
registered trade unions of the work-
The number of health and safety rep-
place in order to consult or bargain
resentatives for a workplace or section
in good faith and conclude an agree-
thereof shall, in the case of shops and
(3) In collaboration with his employer,
ment concerning the:
(2) Identify potential hazards and potential major incidents at the workplace.
offices, be at least one health and safety
examine the causes of incidents at
(a) Nomination and election of health and
representatives for every 100 employ-
ees, or part thereof and in the case of
(4) Investigate complaints by any em-
(b) Terms of office (the period of time
all other workplaces, at least one health
ployee relating to that employeeâ€™s
for which they are elected) and the
and safety representative for every 50
health or safety at work.
circumstances and prescribed manner
employees, or part thereof.
(5) Make representations to the employer
in which they may be removed as
If an inspector of labour is of the
or a health and safety committee on
health and safety representatives.
opinion that the number of health and
matters arising from the above para-
(c) Manner in which vacancies are to
safety representatives in the workplace
graphs, or where such representa-
is inadequate, he may give notice in writ-
tions are unsuccessful, to an inspec-
(d) Manner in which health and safety
ing directing the employer to designate
tor of labour.
representatives must perform their
the required number of employees to act
(6) Make representations to the employer
functions in terms of the Act.
as health and safety representatives.
on general matters af fecting the
PRECAST | ISSUE TWO | 2017
employer, who may be present during
“Manufacturers must have at least one health and safety representative for every 50 employees, or part thereof.”
(8) Participate in consultations with
inspectors at the workplace and
accompany inspectors on inspections
of the workplace.
(9) Receive information from inspectors,
as contemplated in section 36 of
(B) A health and safety representative
shall, in respect of the workplace
or section of the workplace for which
(6) Participate in any health and safety
he/she has been designated, be en-
(C) An employer shall provide such fac-
(1) Visit the site of an incident at all reason-
ilities, assistance and training as a
health and safety of employees at
able times and attend any inspection.
health and safety representative may
(2) Attend any investigation or formal
reasonably require and that have been
(7) Inspect the workplace, including any
agreed upon for the carrying out of
article, substance, plant, machinery
(3) Insofar as it is reasonable and nec-
or health and safety equipment there-
essary for performing his functions,
(D) A health and safety representative
in, with a view to protecting the
inspect any document which the
shall not incur any civil liability by
health and safety of the employees,
employer is required to keep in terms
reason of the fact only that he failed
at such intervals, as may be agreed
of this Act.
to do anything which he may do or is
upon with the employer. The health and
(4) A ccompany an inspec tor on any
required to do in terms of this Act.
safety representative shall give rea-
sonable notice of his attention to
(5) With the approval of the employer, be
carry out such an inspection to the
inquiry held in terms of this Act.
accompanied by a technical advisor.
Swift concrete production with ensured concrete performance SIKARAPID® TECHNOLOGY Cost efficient concrete High early strength development Accelerated hardening Reduction or elimination of heat or steam curing Sustainable and environmentally friendly production |
PRECAST ISSUE TWO www.sika.co.za
COST-CUTTING LEADS TO CBR WA The past five years have seen an upward spike in concrete block retaining (CBR) wall failures. This concerning situation was further highlighted during the heavy rains around Gauteng in December 2016 and March 2017, with at least half a dozen significant failures. While heavy rains certainly exacerbate the problem, there appears to be a fairly regular stream of failed and collapsed CBR walls. So why is there no consumer protest,
• They are highly suitable for greening
their CBR purchase decisions, irrespec-
especially when it involves huge expense,
and the growth of vegetation.
tive of whether a wall design satisfies
potential injury and even fatalities? Imag-
This is why CBR walling is often the
ine the outrage if the same frequency of
preferred retaining wall choice. Which is
sound engineering principles. What should happen at the very
failure pertained to bridges and buildings,
as it should be, because if fundamental
outset of any CBR project with walls
the motor industry or any profession in
engineering principles were followed
higher than 2,5m is the appointment of
which essential engineering principles
in design and construction, CBR wall
an independent structural engineer to
required for the maintenance of accept-
failures would be lower than 0,2%.
take responsibility for the proper design
able standards of function, durability and
and construction of the wall. This involves
safety were disregarded.
striking a balance between best-practice
How has this situation been allowed to
engineering and cost, with the overrid-
happen? The answer, or rather answers,
ing aim of building a wall which will last
follows in this article based on an inter-
decades and longer.
view given to Precast’s coastal media
Once completed, the design should
representative, David Beer, by geotechin-
be submitted to a geotechnical engineer
cal engineer and MD of Verdicon Consult-
for review. And should the project prove
ing Engineers, Trevor Green and general
complex, due to considerations such as
manager of MVA Bricks, Vernan Small.
unstable soil conditions, unusually large
Many professionals involved with the
wall loadings or exceptionally high walls,
industry know what it takes to build a
a geotechnical engineer should be ap-
sound wall. Most of their clients do not,
pointed to handle the design.
or, if they do, are not inclined to involve themselves in the technical minutiae of their wall design. However, what all of them do know is that CBR walling offers
Corners cut (Above): An example of a well-constructed CBR wall.
Sadly, in the current South African construction environment, the ideal and
them substantial advantages, including
Moreover, if CBR wall clients followed
reality are light years apart. Most often,
the same rigorous approach to CBR wall
the client, be they the main contractor
• CBR walls remain the most economical
construction as they do in, say, rein-
on the overall project, a property devel-
way of building a retaining wall.
forced concrete and structural design,
oper or property owner, bypasses the
• The system offers ease and speed
there would be no need for this article.
structural engineer and calls for tenders
However, most do not. Instead, what
from CBR contractors. The contrac-
• CBR walls have the ability to follow
happens in the majority of cases is that
tor submits a “design and construct”
clients rely exclusively on price to make
proposal, where the design is either
of construction. any contour.
PRECAST | ISSUE TWO | 2017
ALL FAILURES prepared in-house or by an engineer
to take a long, hard look at the â€œdesign
employed by the contractor.
and constructâ€? model and the practice
The pressure on the contractor and
of awarding work based purely on cost.
engineer to win the tender is immense,
When skimping first began, the ef-
with the result that engineering integrity
fects were not immediately apparent,
in wall design is steadily eroded. CBR wall
but over the years it has grown into large
clients, who have other priorities to deal
material deficiencies. One of the results
with, are generally unaware of this, which
is that clients now have unreasonable
is a significant factor in why so many
expectations about what a wall should
cost and are appointing contractors who
During the good times when there was
take chances on every job. Without real-
abundant work for all in SA, this â€œdesign
ising it, the client then assumes the risk.
and constructâ€? model worked and stand-
What CBR contractors are tempted
ards were maintained. However, since
to do is assume that the most optimistic
2010, when demand for construction
scenario will apply to their wall and then
projects fell dramatically, CBR work has
prepare their tender submission accord-
become much harder to find, a situation
ingly. This is unrealistic. Geotechnical
which greatly increases the incentive for
information, ground water and loading
cost-cutting. And this is exactly what
conditions, both structural and traffic-
has happened. It began with small cuts,
based, have to be carefully evaluated.
but these have increased incrementally
One cannot simply assume that the site
to the point where some walls are barely
will remain dry and that perfect condi-
standing once the contractor leaves the
tions will prevail. Moreover, some fat
site. And those contractors who actu-
must be included in the design to allow for
ally do submit designs based on good
unknown factors, such as seismic events
engineering practice do not get the work.
(small earthquakes) and some ground water flow. Ground is a volatile medium and
is highly variable. It doesnâ€™t help to build
A tender only needs to be a few rand
a wall which is only 90% compliant. All
per square metres less to be won. The problem is that if a wall falls down, it is not only the contractorâ€™s problem â€“ it becomes the whole projectâ€™s problem and the entire professional team gets dragged into the mess. It involves damage to reputations and to adjacent properties, as well as expensive litigation, not to mention the cost of rebuilding the wall. Surely this is a compelling incentive
PRECAST | ISSUE TWO | 2017
G e n u i n e
c o m p e t i t i o n i s
c o n s u m e r Imitators are
â€œTypically, the only solution for repairing collapsed walls is a rebuild.â€? (Above, from left): Two examples of failed CBR walls; an example of a well-constructed CBR wall.
Find your nearest supplier www.terraforce.com
Te l : 0 2 1 4 6 5 1 9 0 7
walls above 2,5m should only be designed on the basis of a geotechnical report.
be removed lowers the cost of the wall.
It is imperative that the way work is
Good drainage, too, is absolutely criti-
tendered and awarded be reviewed be-
cal to the stability of a wall, as is the fill
cause the reputation of the entire CBR
material behind the wall. The latter should
wall industry is at stake. This will have
Cost-cutting comes in many guises, but
comprise G7 or better and be properly
to be motivated by the clients, once they
all undermine the structural integrity and
compacted in 150mm layers and water
realise that saving a few rand on a retain-
safety of the walls. Cheaper and lighter
should always be drained as quickly as
ing wall is false economy – particularly
hollow blocks, for instance, might be used
possible. At a bare minimum, a circular
given that alternatives to CBR walls are
on a very high wall. This results in cracked
drain should be installed at the back of
so much more expensive.
blocks due to the large amounts of com-
the reinforced zone, with outlet pipes
Certainly, most of the designers who
pressive force exerted by high walls.
spaced every 5m or 6m. In cut-and-fill
work for CBR wall contractors would be
Alternatively, a block might not be made
walls, drainage at the bottom of the wall
happy for the model to change. At the very
with enough cement (ie sub-standard
should be supplemented so that any water
least, property-owners and developers
manufacture of the block itself).
which reaches the face drains speedily.
should be wary. They should not automati-
However, by far the most common
cally opt for the cheapest wall and need to
problem is skimping on the geosynthetic
ensure that the contractors they appoint
reinforcing, either by reducing its depth
Typically, the only solution for repairing
are competent and experienced special-
and/or strength or by increasing the spac-
collapsed walls is a rebuild, because all
ists. A well-built wall costs a little more,
ing from, say, every third block to every
the other alternatives – such as piling,
but everyone gains in the long run.
fourth, the former being the most preva-
soil nails, anchors and grouting – are so
The Concrete Manufacturers’ As-
lent. In an ideal wall, the ratio of geofabric
specialised that they are more expensive
sociation NPC (CMA) has published two
wall height should be 70%, but over time
than rebuilding. The most cost-effective
brochures on CBR walling: a design manual
this ratio has slumped to as low as 50%
solution is to rebuild with a more ap-
and an installation manual. These should
in certain instances. Some contractors
propriate design, perhaps with additional
form part of any property developer’s
even use filter geosynthetics for reinforc-
drainage or better construction, or a
library and they are available from the
ing, which are almost useless. In cut-face
combination of all three. Better still would
CMA at nominal cost. Contact Henry
walls, where soil is removed and replaced,
be to design and construct the wall cor-
Cockroft on tel: 011 805 6742 or via
any reduction in the amount of material to
rectly in the first place.
email at: email@example.com.
We are there when you learn
Need to conquer concrete? Our School of Concrete Technology offers special on-site and tailor-made courses to suit your requirements. Study concrete with us. www.theconcreteinstitute.org.za PRECAST | ISSUE TWO | 2017 +27 11 315 0300
PRECAST CONCRETE MAXIMISES
PROPERTY INVESTMENT Situated a stone’s throw from Stellenbosch, Nooitgedacht Village is an upmarket estate which is being built with several precast concrete elements supplied by CMA member, TopFloor. When completed, it will comprise an exciting mix of residential, commercial and retail components which offer attractive, safe Cape winelands living. With the retail and commercial elements
“Our aim is to take the hassle out of
yet to be built, the site currently com-
construction and get the developer and
prises several types of very attractive
the professional team onto their next site
residential property, including upmarket
as quickly as possible. For example, at
three- to five-bedroomed houses on
Nooitgedacht, we’ve been involved in the
freehold stands and a mix of sectional
primary and secondary engineering design
title units ranging from three-bedroomed
stages and are providing the cranes and
cluster houses to duplex units and one-
trucks to install the precast elements.
We’ve also spent a lot of time before and
construction, commercial, retail and, of
during construction liaising with the ar-
course, residential,” says Prinsloo.
One of the common factors linking all the units is that they are multi-storeyed
chitects and structural engineers.
TopFloor precast concrete is pro-
and are being built with TopFloor’s pre-
“Precast concrete construction is
duced in a controlled factory environment
stressed hollow-core slabs for the upper-
undoubtedly quick. Units are installed
and uses the latest computer-aided
level flooring, precast concrete beams
in a matter of hours, rather than the
designs. This guarantees a consistently
to support the slabs, precast concrete
weeks it takes for in-situ construction.
high level of quality which is very difficult
staircases and precast concrete lintels.
And in the case of upper-level flooring,
to achieve with in-situ construction.
precast hollow-core slabs allow other
Moreover, it is recyclable and can be
services, such as masonry, electrical and
used to produce concrete bricks and
According to TopFloor MD, Wessel Prins-
plumbing, to commence work as soon as
in road construction. Very little waste
loo, one of the major advantages of build-
is produced in the production process
ing with precast is that it minimises on-
because all materials are used optimally.
site clutter and wastage, thus speeding
Speed of construction
up construction time immensely.
“Further time-savers are the smooth
construction of all types of buildings and
Precast concrete is safe for the
soffits of the slabs and rough finishes on
does not exude harmful substances into
their upper sides. This enables them to
be painted without the need for skimming and makes screed bonding hassle-free. Another advantage of using hollow-core flooring is its superior thermal and sound insulation properties. “All types of property development lend themselves to precast concrete
PRECAST | ISSUE TWO | 2017
(Top, from left): Two semi-detached sectional title units; one of the freehold houses at Nooitgedacht Village. (Above): One of the TopFloor precast concrete staircases at Nooitgedacht Village. (Left): The smooth soffit finish of TopFloor’s hollow-core slabs creates an attractive ceiling in this Nooitgedacht Village house.
“We opted for a demountable design
“The steel frame comprised vertical col-
because we have other medium-term
umns – mounted on concrete pad footings
development plans for this valuable Beach
– and steel cross-beams which supported
Rd stand which commands spectacular
the prestressed hollow-core slabs. The
views over Granger Bay,” says V& A
framework was reinforced with a minimum
development executive Martin Kearns.
of cross-bracing to provide as much car
“Given the demand for parking at the
space as possible. We achieved this by
Waterfront, it made sense to use the
installing additional reinforcing in the form
land productively in the interim, especially
of steel ‘ladder’ bracing at first-floor level
with a building which could be unbolted
along the full length of each elevation.”
and re-used elsewhere with minimal onsite demolition works.”
The concept of a demountable struc-
The parkade has been designed to accom-
ture was initiated by V&A’s development
modate a fourth parking level and to fa-
project manager, Niaz Ahmed, and was
cilitate this, the steel columns protrude
PRECAST TO BUILD MECCANOSTYLE V&A PARKADE
structurally developed by LH Consulting
above the third-level parking section. In
Engineers. MLB Architects converted
addition to supplying 8 800m² of pre-
the concept into blueprint and NMC
stressed hollow-core slabs each measur-
Construction was responsible for the
ing 7,5m x 120cm x 160mm for the two
construction and assembly work. Other
upper parking levels, Portland Hollowcore
members of the construction team in-
also supplied 16 precast staircases for
cluded BTKM Quantity Surveyors and
the building’s four stairwells.
SA’s first demountable parkade has been constructed at Cape Town’s V&A Waterfront. Providing the V&A with an additional 540 parking bays over three floors, the structure was erected using bolt-on steel frames supplied by Union Steel and prestressed hollow-core concrete slabs supplied by CMA member Portland Hollowcore. PRECAST | ISSUE TWO | 2017
KLS Consulting Engineers.
A third precast element came in the form of exposed aggregate concrete
block pavers, supplied by Inca Concrete
“The use of precast concrete slabs on
Products, which were used to create an
the upper two levels and on the inter-level
attractive surface on the ground-floor
vehicle ramps is what really made this
parking level. These, too, can be lifted
structure viable,” says Ahmed.
and relaid elsewhere. Although the Beach
“We could, of course, have relied solely
Rd parkade is classified as a temporary
on steel, but that would have rendered
structure, its steel and concrete mate-
the entire venture impracticable. Hollow-
rial mix means that it can enjoy the life-
core slabs not only offered re-usability,
span of a normal structure. And because
but – because they’re lighter than in-situ
it has no lateral walling to speak of, no
concrete – less steel was required for
mechanical ventilation is required.
the framework. Moreover, their ease and speed of installation using mobile cranes meant that this was a genuine fast-track project which was completed in time to alleviate an increased demand for parking over the festive season.
(Above, from top): The attractive façade of the V&A’s recently-constructed parkade showing the slat screening on one of the elevations, the precast staircase, some cross-bracing and the “ladder” bracing; prestressed hollow-core beams above and below and the “ladder” bracing seen on the left of the image; steel columns extend above the third level in preparation for the addition of a fourth level.
A strong foundation for infrastructure success
ADDING GRACE TO UPMARKET CAPE HOUSING DEVELOPMENT
Concrete roof tiles, manufactured by CMA member Marley Roof Tiles, are being used exclusively in the construction of Hillwood, a flagship residential estate currently under development by non-profit company Garden Cities (RF), in Cape Town’s northern suburb of Pinehurst. Marley’s Spectrum Slate Double Roman Plus was selected for all the hipped roofs and its Antique Amber Double Roman tile was selected for the gable-to-gable roofs to enhance the French Provençal architectural theme of the development. Scheduled for completion in October 2018, the houses are being built in three- and four-bedroom designs and sell from R2,35 million-R3,1 million. The project’s main contractor is Garden Cities’ construction arm, Pinelands Development Company. I15457
Marley regional commercial director, Juliano Amodio, says that besides their obvious aesthetic attributes, concrete roof tiles come with several other benefits. “They offer one of the most cost-effective roofing materials and are largely maintenance-free. They don’t need painting and don’t rust. They also have good thermal properties and don’t require as much insulation material as steel roofs do to meet legal thermal roofing requirements.” (Top): Marley’s Antique Amber Double Roman tile was selected for the gable-to-gable roofs at Hillwood. (Below): Marley’s Spectrum Slate Double Roman Plus tiles accentuate the French Provençal architectural theme at Hillwood.
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.
Visit us on www.rocla.co.za for our nationwide branches PRECAST | ISSUE TWO | 2017
The Concrete Institute (TCI) has announced
is widely regarded as the definitive
was first involved in the sixth edition
that Prof Mark Alexander, who at the end
handb ook on concr e te technolog y.
of the reference book in 1986. T CI
of 2015 retired from the Department of
“Mark’s been very involved in lecturing
is therefore proud to announce that
Civil Engineering at UCT, will edit the 10th
for the Advanced Concrete Technol-
Mark has agreed to edit the 10th edition
edition of the world-renowned “concrete
ogy course pr esented by the T CI’s
of Fulton’s, which we hope to publish in
bible”, Fulton’s Concrete Technology.
School of Concrete Technology since
2018,” says Perrie.
Bryan Perrie, managing director of
the early 1990s. He’s also been heavily
Alexander was chairman of the TCI’s
TCI, believes Alexander has all the cre-
involved in writing and reviewing chap-
forerunner, the Cement & Concrete In-
dentials for the new revision of what
ters of Fulton’s Concrete Technology and
stitute, from 2011-2013.
LATEST REVISION OF “CONCRETE BIBLE”
PHOTO CORRECTION In the last issue of Precast, we presented an article titled Quality Pipes Required for New Project about Rocla’s successful supply of pipes for the Diepkloof Zones 5 and 6 project. It was a great story, but – to our embarrassment – we mistakenly used an unrelated piping photograph to illustrate it. We apologise for this and to ensure our readers get a good look at the pipes, we’ve included two photographs of
the project in question.
0861 762 781 (Nationwide) www.smartstone.co.za
PAVING ROADS IN OUTLYING AREAS Durability of roads, as well as reducing the environmental impact on surroundings and the creation of employment, were considerations for the awarding of some large-scale paving projects for CMA member Technicrete. Among the most recent projects the
company supplied was an environmentally
“The openings in each block and between
friendly road system designed to blend
blocks are sized to benefit from enough
with natural landscapes, while offering
vegetation growth to make the surface
suitable durability and traction for motor
appear ‘natural’, while still maintaining
vehicles at Du Pont Pioneer’s newly-built
structural integrity. Similarly, it’s a good
research facility at Delmas, Mpumalanga.
solution for Jeep track-type installations.”
Technicrete’s Armorflex system was
Michael Magner, director at Activate
specified by both the architects and
Architects, adds that the Du Pont
engineers for use on construction of the
research facility was built on farmland
new entrance road and was chosen due
and the product blended perfectly with
to the client’s requirement for a “green”
the rural setting, while providing an
road that could blend in with the natural
erosion-resistant roadway and keeping
surrounds of the facility, while offering
into long mats which can be anchored
traffic at a slower pace due to the slight
suitable durability to traffic loading and
into in-situ soil. This further assists
roughness of the finishes on the product.
environmental conditions, with an im-
with stabilisation of the blocks and road
The project entailed a 400m-long roadway
pressive final appearance. The project,
surface. The loose, but interlocking de-
and parking area for approximately 40
which commenced in January 2016, was
sign allows the concrete road surface
cars. “Armorflex and kerbs were chosen
completed at the end of January 2017.
to remain flexible to movements, elimi-
by the project’s structural/civil engineer,
“The Internationally Licensed Armor-
nating the cracking and spalling issues
who’s had prior successes with these
flex system is manufactured in SA by
that plague solid concrete surfaces,
product ranges on other applications.
Technicrete and is the only similar type
even when exposed to regular inclement
Good access to the specification team
system available locally. It has the facil-
weather,” says Justin Kretzmar, sales
at Technicrete for reliable supplier-based
ity to wire-tie adjacent blocks together
engineer for Technicrete.
technical input made a positive impact for
PRECAST | ISSUE TWO | 2017
us on this project,” says Magner. “Armorflex road product was easy to install and the cells, when seeded and filled with topsoil, will enhance the growth of grass. The very design of Armorflex enables roots to penetrate the geotextile below the blocks, which enhances anchorage of the installation,
giving a very secure and sturdy surface for vehicle traffic. On this project, the final appearance was very good and blended well with the natural rural aesthetics of the completed facility,” says Probuild’s site agent on the Du Pont Pioneer project, Mark Guthrie. Moletjie Road In another equally impressive project, Limpopo’s Public Works & Infrastructure Department announced that R1,2 billion
regularity of the bus traffic.”
forces on this R2 million project with
had been earmarked for road refurbish-
The project consisted of a combina-
MacP Construction. Where heavy traf-
ment and maintenance to be rolled out
tion of 50mm Bond Bricks together with
fic is experienced, our Bond Brick paving
over the next three years. Included in this
kerbs, 60mm and 80mm Double Zig-Zag
blocks are perfect because of their well-
roll-out was maintenance to a section of
Grey pavers and kerbs. The Bond Brick
established reputation for longevity and
the Moletjie Road Project in Polokwane
is a traditional paver that offers econo-
quality, while still offering a good finish
that was to be upgraded from gravel
my and durability and is very well suited
aesthetically. We aim to ensure that all
to paving. Technicrete’s Bond Brick and
to commercial and domestic surfaces.
stock is supplied as per client require-
kerbs were selected for this project. Mak ap ani Modip a, CE O o f MacP
ments and this was the case on the MoDurable solution
Construction, says: “There was no es-
“It’s been a preferred choice not only of
tablished pavement on this section of
local municipalities, but of private commer-
Moletjie Road – it was a gravel walkway
cial developments as well,” says Hendrik
that needed to be upgraded to a paved
Steenkamp, sales consultant for Techni-
surface. Included along this stretch of
crete ISG in Polokwane. “Our precast con-
walkway, a 1,3km bus stop had to be
crete kerbs are an ideal edge restraint in
accommodated in the construction. To
the construction of roads, kerb and gutter
do this, we chose the Technicrete Bond
systems. We can now also offer our Figure
Brick and kerb products for their dura-
C900 mountable kerb, which can be used
bility. This was a key factor for the bus
in traffic-calming measures.
stop development, due to the weight and
PRECAST | ISSUE TWO | 2017
“We were pleased to have joined
letjie Road Project,” says Steenkamp.
“The loose, but interlocking design allows the concrete road surface to remain flexible to movements.”
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: GAUTENG PILLAR: PB/PI BOSUN BRICK MIDRAND (PTY) LTD Tel: (011) 310 1176 PROVINCE/COUNTRY: GAUTENG PILLAR: PB/PI BOSUN BRICK BRITS (PTY) LTD Tel: (012) 250 1711 PROVINCE/COUNTRY: NW PILLAR: PB/PI BOSUN BRICK PORT ELIZABETH (PTY) LTD Tel: (041) 405 0100 PROVINCE/COUNTRY: EC PILLAR: PB PANDA (PTY) LTD Tel: (00267) 244 2107/8 PROVINCE/COUNTRY: BOTS PILLAR: PB/PI BRICKCAST INDUSTRIES CC Tel: (031) 507 5525 PROVINCE/COUNTRY: KZN PILLAR: PB/PI BANZI TRADE 31 (PTY) LTD T/A BRICKIT Tel: (011) 023 6708 PROVINCE/COUNTRY: GAUTENG PILLAR: PB/PI 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 CIVILWORKS (PTY) LTD REAL TIME INVESTMENTS Tel: (011) 903 7023 PROVINCE/COUNTRY: GAUTENG PILLAR: PB/PI CONCRETE UNITS (PTY) LTD Tel: (021) 386 1923 PROVINCE/COUNTRY: WC PILLAR: PB/PI CONCRETE UNITS (PTY) LTD Tel: (016) 362 2236 PROVINCE/COUNTRY: GAUTENG PILLAR: PB/PI CONFRAMAT (PTY) LTD Tel: (0861) 33 5599 PROVINCE/COUNTRY: GAUTENG PILLAR: PB/PI COROBRIK (PTY) LTD Tel: (031) 560 3111 PROVINCE/COUNTRY: KZN PILLAR: PI CORESLAB (PTY) LTD Tel: (087) 232 2462 PROVINCE/COUNTRY: LIMPOPO PILLAR: PB/PI DERANCO PRECAST (PTY) LTD Tel: (041) 463 3338 PROVINCE/COUNTRY: EC PILLAR: PB/PI EAGLE ROOF TILES (PTY) LTD Tel: (044) 874 0290 PROVINCE/COUNTRY: WC PILLAR: PB ECHO PRESTRESS (PTY) LTD Tel: (011) 589 8800/8899 PROVINCE/COUNTRY: GAUTENG PILLAR: PB ECHO FLOORS (PTY) LTD Tel: (011) 668 1900
PROVINCE/COUNTRY: GAUTENG PILLAR: PB ECHO PRESTRESS DURBAN (PTY) LTD Tel: (032) 947 3067 PROVINCE/COUNTRY: KZN PILLAR: PB ENVIRO-CAST (PTY) LTD Tel: (016) 0040018 PROVINCE/COUNTRY: GAUTENG PILLAR: PB/PI INCA MASONRY PRODUCTS (PTY) LTD Tel: (043) 745 1215 PROVINCE/COUNTRY: EC PILLAR: PB/PI KEYSTONE WALLING CC Tel: 082 850 3512 PROVINCE/COUNTRY: GAUTENG PILLAR: PB/PI LATEGAN CEMENT WORKS (PT Y) LTD Tel: (021) 873 1154 PROVINCE/COUNTRY: WC PILLAR: PB/PI
TECHNICRETE (PTY) LTD Tel: (011) 672 1425 PROVINCE/COUNTRY: GAUTENG PILLAR: PB/PI TOPFLOOR CONCRETE (PTY) LTD Tel: (021) 951 7700 PROVINCE/COUNTRY: WC PILLAR: PB VANSTONE PRECAST (PTY) LTD Tel: (012) 541 2056/1808 PROVINCE/COUNTRY: GAUTENG PILLAR: PB/PI WEST END CEMENT BRICKS (PTY) LTD Tel: (011) 851 1005 PROVINCE/COUNTRY: GAUTENG PILLAR: PB/PI NON-PRODUCER MEMBERS ABEL EQUIPMENT CC Tel: (044) 874 1876 PROVINCE/COUNTRY: EC ASH RESOURCES (PTY) LTD Tel: (011) 657 0230 PROVINCE/COUNTRY: GAUTENG
PROVINCE/COUNTRY: POLAND TERRAFORCE (PTY) LTD Tel: (021) 465 1907 PROVINCE/COUNTRY: WC ASSOCIATE MEMBERS ASPASA Tel: (011) 791 3327 PROVINCE/COUNTRY: GAUTENG BRITISH PRECAST CONCRETE FEDERATION Tel: +(44) 116 232 5170 PROVINCE/COUNTRY: UK CONCRETE SOCIET Y OF SOUTHERN AFRICA Tel: (012) 348 5305 PROVINCE/COUNTRY: GAUTENG CPI CONCRETE PLANT INTERNATIONAL Tel: (02236) 962390 PROVINCE/COUNTRY: GERMANY ILIFA AFRICA ENGINEERS (PTY) LTD (012) 362 1473 PROVINCE/COUNTRY: GAUTENG
MARLEY ROOFING (PTY) LTD Tel: (011) 316 2121 PROVINCE/COUNTRY: GAUTENG PILLAR: PB
BASF CONSTRUCTION CHEMICALS SOUTH AFRICA (PTY) LTD Tel: (011) 203 2400 PROVINCE/COUNTRY: GAUTENG
MOBICAST (PTY) LTD Tel: 086 111 2346 PROVINCE/COUNTRY: WC PILLAR: PB/PI
BIRKENMAYER H (PTY) LTD Tel: (011) 970 3880 PROVINCE/COUNTRY: GAUTENG
SEKHUKHUNE & ASSOCIATES Tel: (012) 346 1945 PROVINCE/COUNTRY: GAUTENG
CHRYSO SOUTHERN AFRICA (PTY) LTD Tel: (011) 395 9700 PROVINCE/COUNTRY: GAUTENG
SNA CIVIL & STRUCTURAL ENGINEERS Tel: (012) 842 0000 PROVINCE/COUNTRY: GAUTENG
MONIER COVERLAND (PTY) LTD Tel: (011) 222 7300 PROVINCE/COUNTRY: GAUTENG PILLAR: PB/PI MPUMALANGA BRICK & CRETE (PTY) LTD Tel: (017) 811 5662 PROVINCE/COUNTRY: MPUM PILLAR: PB/PI MVA BRICKS CC Tel: (012) 386 0050 PROVINCE/COUNTRY: GAUTENG PILLAR: PI PORTLAND HOLLOWCORE SLABS (PTY) LTD Tel: (021) 972 1111 PROVINCE/COUNTRY: WC PILLAR: PI REMACON PRODUCTS CC Tel: (011) 393 5504 PROVINCE/COUNTRY: GAUTENG PILLAR: PI
DECCAN DIE CASTINGS (PVT) LTD Tel: 91 80 28524121 PROVINCE/COUNTRY: INDIA DELTA BLOC SOUTH AFRICA (PTY) LTD Tel: (011) 024 4604 PROVINCE/COUNTRY: GAUTENG DICK KING LAB SUPPLIES (PTY) LTD Tel: (011) 499 9400 PROVINCE/COUNTRY: GAUTENG ECONO CAST (PTY) LTD Tel: (011) 662 2159 PROVINCE/COUNTRY: GAUTENG ECO-MATCH (PTY) LTD Tel: (011) 082 9864 PROVINCE/COUNTRY: GAUTENG
JC PAVING CONSULTING Tel: (011) 431 0727 PROVINCE/COUNTRY: GAUTENG
SARMA Tel: (011) 315 0300 PROVINCE/COUNTRY: GAUTENG TACO VOOGT CONSULTING ENGINEER Tel: (012) 669 0125 PROVINCE/COUNTRY: GAUTENG TJEKA TRAINING MATTERS Tel: (011) 665 2777 PROVINCE/COUNTRY: GAUTENG YOUNG & SATHARIA CONSULTING CIVIL ENGINEERS Tel: (031) 207 7252 PROVINCE/COUNTRY: KZN CONTRACTOR MEMBERS
HAWKEYEPEDERSHAAB Tel: 00 459645 4000 PROVINCE/COUNTRY: DENMARK
BUFFALO RETAINING WALLS CC Tel: (016) 366 1801 PROVINCE/COUNTRY: GAUTENG
REVELSTONE (CAPE) (PTY) LTD Tel: (0861) 173 835 PROVINCE/COUNTRY: WC PILLAR: PI
HYDRAFORM INTERNATIONAL (PT Y) LTD Tel: (011) 913 1449 PROVINCE/COUNTRY: GAUTENG
DECORTON RETAINING SYSTEMS (PTY) LTD Tel: (021) 875 5155 PROVINCE/COUNTRY: WC
ROCLA (PTY) LTD Tel: (011) 670 7600 PROVINCE/COUNTRY: GAUTENG PILLAR: PB/PI
KERNEOS SOUTH AFRICA (PTY) LTD Tel: (011) 444 3090 PROVINCE/COUNTRY: GAUTENG
FRICTION RETAINING STRUCTURES (PT Y) LTD Tel: (011) 608 4321 PROVINCE/COUNTRY: GAUTENG
SHUKUMA BRICKS (PTY) LTD Tel: (041) 372 1013 PROVINCE/COUNTRY: EC PILLAR: PB SILVERTON PRECAST (PTY) LTD Tel: (012) 804 4525 PROVINCE/COUNTRY: GAUTENG PILLAR: PI SIMSTONE (PTY) LTD Tel: (016) 362 2181/2 PROVINCE/COUNTRY: GAUTENG PILLAR: PB/PI SMARTSTONE (PTY) LTD Tel: (011) 310 1161 PROVINCE/COUNTRY: GAUTENG PILLAR: PB/PI SOUTHERN PIPELINE CONTRACTORS (PTY) LTD Tel: (011) 914 8500 PROVINCE/COUNTRY: GAUTENG PILLAR: PI
KOBRA MOULDS B.V. Tel: 003111 356 2460 PROVINCE/COUNTRY: NETHERLANDS MANITOU SA (PTY) LTD Tel: (011) 975 7770 PROVINCE/COUNTRY: GAUTENG O.C.E.M. S.R.L. Tel: 00393 357 999 084 PROVINCE/COUNTRY: ITALY PAN MIXERS SA (PTY) LTD Tel: (011) 578 8700 PROVINCE/COUNTRY: GAUTENG QUANGONG MACHINES CO LTD Tel: +865 958 679 9557 PROVINCE/COUNTRY: CHINA SIKA SOUTH AFRICA (PTY) LTD Tel: (031) 792 6500 PROVINCE/COUNTRY: KZN TECHMATIK S.A. Tel: (0048) 608 422 300
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
POWERGATE CONSTRUCTION CC Tel: 071 603 5070 PROVINCE/COUNTRY: GAUTENG VALCAL INTERNATIONAL EXPORT CC Tel: (011) 867 2471 PROVINCE/COUNTRY: GAUTENG CEMENT MEMBERS AFRISAM SOUTH AFRICA (PTY) LTD (011) 670 5500 PROVINCE/COUNTRY: GAUTENG LAFARGEHOLCIM (PTY) LTD (011) 657 0000 PROVINCE/COUNTRY: GAUTENG PPC LTD (011) 386 9000 PROVINCE/COUNTRY: GAUTENG SEPHAKU CEMENT (PTY) LTD (012) 684 6300 PROVINCE/COUNTRY: GAUTENG
PI – Precast Infrastructure PB – Precast Building
PRECAST | ISSUE TWO | 2017
EIRICH R-TYPE MIXERS + HYDRONIX MOISTURE CONTROL = TOTALLY CONSISTENT CONCRETE WITH EVERY BATCH
HYDRO CONTROLAUTOMATES MIXING A. BATCH IN MIXER B. CEMENT DISCHARGE BY TIMER C. MONITORED FLAT LINE FOR DRY MIX AND MOISTURE MEASUREMENT D. WATER DISCHARGE E. MONITORED FLAT LINE FOR WET MIX F. TIMED DISCHARGE
COST SAVINGS WITH EIRICH RV19 INTENSIVE MIXER SAVINGS IN CEMENT, PIGMENTS, ENERGY, WATER AND REJECT RATES HAVE BEEN REPORTED FOR 30 YEARS. PRECISE BLENDING AND HOMOGENOUS MIXES ARE ACHIEVED WITH SHORT MIXING TIMES. CONCRETE QUALITY AND SURFACE FINISH SPECIFICATIONS RISE CONTINUOUSLY. THE EIRICH R-TYPE MIXER IS BEST SUITED TO THIS DEMANDING ENVIRONMENT.
EIRICH RV19 INTENSIVE MIXER: INCLINED PAN CREATES STRONG VERTICAL MIXING ACTION AGITATOR BLADES BREAK UP LUMPS AND DISTRIBUTE WATER WATER AND CEMENT IS DRAWN THROUGH THE MIX BY A VORTEX CREATED AT THE SHAFT COMBINED FLOOR AND WALL SCRAPER DIVERTS MATERIAL INTO THE PATH OF THE AGITATOR FLOOR SCRAPER ALSO ASSISTS WITH FAST DISCHARGE
H. Birkenmayer • Website: www.birkenmayer.co.za • Tel: +27 11 970 3880 • E-mail: firstname.lastname@example.org