Precast volume 7 • issue 3 • 2013

PRECAST VOLUME Seven ISSUE 3 • 2013

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the cma – QUALITY CAST IN CONCRETE

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• Mammoth culverts for stacker tunnels

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• Precast concrete panels add lustre to green building

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contents

1

precast contents THE CONCRETE INSTITUTE

2

TECHMATIK SETS SIGHTS ON AFRICA

2

LIFETIME ACHIEVEMENT AWARD FOR

GÜNTER KOCH 3 EZETHU LOGISTICS SECURES

AFRISAM DELIVERY CONTRACT

4

MUCH-MALIGNED CONCRETE HAS

EXCELLENT ECOLOGICAL PROFILE 4

TOTALLY CONCRETE expo 2014

4

CMA HOSTS BFT INTERNATIONAL

CHEMICAL ADMIXTURES

27 ECO-TILE® EXTRUSION FOR A BRIGHT

HOUSING FUTURE

27 Greater MOISTURE

MEASUREMENT ACCURACY

PRECAST VOLUME SEVEN ISSUE 3 • 2013

The cement silos (left) and ash silos at Sephaku Cement’s 155 ton-per-hour cement milling plant, currently under construction south west of Delmas in Mpumalanga. The project incorporates the latest environmentally-friendly technology with particular emphasis on high efficiencies and reduced power consumption. Production is scheduled to begin in the early part of 2014.

7

BLUE ROUTE mall PERMEABLE

PAVING PROJECT

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facturer

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• Mammoth culverts for stacker tunnels

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• Blue Route Mall – responsible urban development

• Precast concrete panels add lustre to green building

ARTICLES

ON THE COVER

THE CMA – QUALITY CAST IN CONCRETE

soc

LAFARGE QUARRY HOSTS KNYSNA RETIREES

26 AFRISAM ADVISES ON

as

5

CONTROL CONTRACT

m

ncrete

2 EXCEPTIONAL SUPPORT FOR

26 ACTOM EXECUTES FAST-TRACK DUST

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NEWS

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10 PRECAST CONCRETE PANELS ADD LUSTRE

TO WATERFRONT OFFICE DEVELOPMENT

Precast is the official journal of the Concrete Manufacturers Association (CMA)

14 PRECAST CONCRETE PREDOMINATES

16 Horn Street, Chloorkop, Kempton Park, 1620

PostNet Suite 8612, Private Bag X32, Kempton Park, 1620

AT ‘THE WILLIAM’

16 CONCRETE BLOCK PAVING CHOSEN

FOR PIETERMARITZBURG URBAN

RENEWAL PROJECT

Tel: +27 11 805 6742, Fax: +27 86 524 9216 E-mail: admin@cma.org.za, Website: www.cma.org.za Publishers Isikhova Publishing & Communications

18 SWAZILAND OPTS FOR PATENTED

PO Box 651793, Benmore, 2010, South Africa

Tel: +27 11 883 4627, Fax: +27 11 883 4627

PRECAST CONCRETE BARRIER SYSTEM

20 MAMMOTH PRECAST CONCRETE

CULVERTS CHOSEN FOR TWeeFONTEIN

STACKER TUNNELS

22 CMA WELCOMES NEW MEMBERS

Website: www.isikhova.co.za Publisher: Andrew Meyer Tel: +27 11 883 4627, Cell 082 456 5175 E-mail: andrewm@isikhova.co.za Editor: David Beer Tel: +27 11 478 0239, Fax: +27 11 678 0254

COVER STORY 12 NEW SEPHAKU PLANT ON TRACK

E-mail: bigsky@ibi.co.za Advertising: Andrea Latham Tel: +27 11 883 4627 E-mail: communications@isikhova.co.za Design, layout and production: Joanne Brook

advertorial 21 pmsa confident of further growth

APPLICATIONS 25 ECHO PRESTRESS builds HIGH

Tel: +27 11 883 4627 E-mail: joanne.studio@isikhova.co.za The views and statements expressed in this publication are not necessarily those of the editor or the publishers and neither he, 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.

STRENGH SECURIT Y WALL

PRECAST VOLUME 7 • ISSUE 3 • 2013

2

NEWS

EXCEPTIONAL SUPPORT FOR THE CONCRETE INSTITUTE The exceptionally high level of support

centre, says sales of publications have also

for, and interest in, the operations of The

been running at very high levels.

For more information about the School training programme, contact eldenem@

Concrete Institute has shown how much

“The marketplace seems relieved that

theconcreteinstitute.org.za and for gen-

the construction industry appreciates the

T he Concr ete Institute is continuing

eral inquiries about publications, contact

Institute’s preservation of the services

to sell all the publications previously

info@theconcreteinstitute.org.za, phone

previously rendered by the now defunct

published by the C&CI. When we exhibited

011 315 0300, or visit www.theconcrete-

Cement & Concrete Institute.

at the recent Totally Concrete expo at the

institute.org.za

Managing dir e c t or, Br y an P er r ie,

Sandton Convention Centre, sales of our

says the volume of inquiries calling for

publications were so high that we had to

advice on concrete technology matters

fetch new stock.”

has not abated, student numbers at the

Battison says the support for the Infor-

Institute’s School of Concrete Technology

mation Centre has come from construction

continue to be high, and demand for the

and building industry members at all levels.

services of the Information Centre has

“We’ve provided reference material for the

been a revelation.

research work of students and top academ-

“It’s been back-to-business almost

ics since re-opening on May 2,” she said.

from the day we announced that AfriSam,

The School of Concrete Technology’s

Lafarge and Sephaku had stepped in to fund

2013 Education Programme has just been

the institute,” Perrie stated.

published and the second edition of the

Mar tha de Jager who, with Susan Battison, manages the CI’s information

‘Concrete Projects for the Garden’ is also now available.

The Concrete Institute stand at the Totally Concrete expo in Sandton.

TECHMATIK SETS SIGHTS ON AFRICA September saw CMA member and precast

approach has realised impressive reduc-

concrete machinery specialist, Techmatik

tions in production costs, with savings of

SA, announce its commitment to an African

up to 40% in power consumption and 20%

marketing initiative at bauma Africa 2013,

in cement usage, in comparison to other

the first such exhibition and conference to

leading precast concrete block-making

be held on the continent.

machinery manufacturers.

This highly successful Polish company

“We have installed over 40 plants in

has been manufacturing plant for the

Europe and Asia since 2007 alone and we

production of various types of vibro-

believe that the potential for our concrete

pressed interlocking paving blocks, kerbs,

casting machinery in Africa is huge.

watercourses, bricks, blocks and other

Techmatik international sales manager, Marcin Nowakowski (left), and sales and marketing specialist, Magdalena Piliszek, seen here with CMA executive director, Wally Armstrong at the Techmatik stand at bauma Africa 2013.

others, this extremely efficient plant is

“Our African breakthrough came this

the largest of its kind in North Africa and

year when we installed a plant in Tripoli,

we anticipate the installation of several

International sales manager, Marcin

Libya. Producing several products including

similar-sized plants in southern Africa,”

Nowakowski, says the company’s innovative

paver s, masonr y blocks, kerbing and

says Nowakowski.

concrete products, since 1989.

Lifetime achievement award presented to GÜnter Koch Long-standing masonry consultant, Günter Koch,

Housing Foundation. T he award recognised

has been presented with a Lifetime Achievement

Koch’s 45 years of passion, vision and pro-

Award by the Minister of Human Settlements,

fessionalism in the promotion of housing built

Provincial Government of the Western Cape, Mr

with cement and concrete products, and his

Bonginkosi Madikizela.

tireless engagement with all sectors of the

The presentation took place on 17 September at an annual gathering of the Southern African

PRECAST VOLUME 7 • ISSUE 3 • 2013

housing industry in striving for the provision of quality affordable housing.

Günter Koch.

NEWS

3

Ezethu Logistics secures AfriSam delivery contract Ezethu Logistics, the empowerment partner of JSE-listed supply chain specialists Cargo Carriers, has been awarded the contract to transport cement from AfriSam’s Ulco operation near Kimberley to the company’s readymix facilities in the Western Cape. Ezethu Logistics has dedicated eight powder tankers to the contract, which will deliver bulk cement to plants in Bellville, Cape Town City and Philippi.

Andre Jansen van Vuuren, Cargo Carriers divisional director of marketing, believes three factors gave Ezethu Logistics the edge: a reputation for reliable, cost-effective supply chain logistics in fuels, chemicals and powders; certified compliance with the best safety, health, environment and quality (SHEQ) standards; and a B-BBEE compliance rating of Level 2.

Service providers’ B-BBEE ratings are an important factor in the awarding of contracts by AfriSam. Ezethu’s Level 2 rating allows AfriSam to claim more than 100% compliance in terms of its procurement charter. This rating, complemented

by Ezethu’s competitive pricing, played a significant role in the company securing the contract.

Since 2003, Cargo Carriers and Ezethu Logistics have pioneered the concept of owner-drivers, providing training and support to allow drivers to become stakeholders in the industry. The result is genuine empowerment, backed by Cargo Carriers’ financial muscle, stringent health and safety standards and a 57-year old reputation for business reliability.

Six of the eight tankers are driver-owned and each vehicle will cover 21 500km per month. Computerized logistics and vehicle tracking facilitate strict shift times and reduced delivery costs without compromising reliability or driver safety.

“We’re really ‘sweating the assets’,” says Jansen van Vuuren. “We stay strictly within industry standards for driving times and shift times, but our logistics give us the edge in turnaround times and load monitoring”.

Ezethu’s growth in the fuels, chemicals and powders sector is testimony to the company’s attention to SHEQ standards, as demonstrated by its ISO 14001, OHSAS 18001 and ISO 9001 certification.

Two Cargo Carriers tankers which will transport bulk cement for AfriSam.

PRECAST VOLUME 7 • ISSUE 3 • 2013

4

NEWS

MUCH-MALIGNED CONCRETE HAS EXCELLENT ECOLOGICAL PROFILE Concrete and cement are often unfairly

use of extenders such as blast furnace

“Concrete has an excellent ecological

blamed for unacceptably high carbon-

slag, fly ash, limestone and other similar

profile compared to other construction

dioxide emissions, comments Bryan Perrie,

materials which would end up in landfills

materials and its social contribution cannot

MD of The Concrete Institute.

if not used by the cement and concrete

be overestimated. It is the second most

Perrie says the current average world-

industry. Another industry contribution

used resource in the world after water, and

wide consumption of concrete is about

towards sustainability is the sourcing

contributes significantly to our standard

a ton per year for every living person.

of synthetic gypsum from industrial by-

of living.

“Notwithstanding this extensive use, the

products from the fertiliser and sulphuric

global cement industry still accounts for

acid industries.”

Perrie believes using concrete makes environmental sense because properties

only about 5% of man-made carbon-dioxide

Perrie says when selecting aggregates

such as economy, thermal mass, fire

emissions. Approximately 40% of this

for sustainable concrete production, it

resistance and water-tightness all add

comes from burning coal and 60% from the

is important not to choose the cheapest

to the sustainability of concrete in the

calcination of limestone. It should also be

sand as this may result in more expensive

built environment. “Concrete structures

remembered that structures are not con-

concrete with a significantly higher carbon-

have optimal energy performance with

structed out of cement but from concrete

dioxide footprint. The use of recycled

associated positive effects on whole-life

- of which cement is but one ingredient.”

concrete as an aggregate will further

energy usage,” he concludes.

T he aver age international level o f

reduce the carbon-dioxide emissions of

carbon-dioxide emissions is about 1 000kg

concrete while simultaneously preserving

per ton of pure cement.

natural resources and eliminating the need

“This value is being reduced by new

for dumping old concrete at landfill sites.

technology and the use of alternative

“Although the proportion of admixtures

fuels in cement kilns, including the burning

in a concrete mix is relatively small, recent

of waste tyres. The primary method of

developments in admixture technology mean

significantly reducing the emissions is to

that admixtures can have a major positive

lower the clinker factor in cement by the

effect on sustainability,” he explains.

Sustainable and striking structures can be achieved with concrete, the second-most used resource in the world.

TOTALLY CONCRETE EXPO 2014 Totally Concrete Expo 2014 will run from

ated with the concrete and construction

economic factors and the global trends

26-28 May at the Sandton Convention

industries. Green initiatives, the entry of

which influence Africa’s construction

Centre in Johannesburg. Totally Concrete is

new and foreign cement manufacturers,

industry will also be highlighted, as will

Africa’s definitive educational and network-

internationalisation, and the significant new

some tools and solutions which assist

ing platform for insights into the latest

opportunities of fered by cross-border

the management of large infrastructural

developments and technologies associ-

deals are on the agenda for 2014. Macro-

projects. View www.totallyconcrete.co.za.

CMA HOSTS BFT INTERNATIONAL BF T IN T E RN AT ION A L e di t or -in - chie f

covered manufacturers of concrete and

Christian Jahn (centre), in discussion with

precast concrete products in addition

CMA executive director, Wally Armstrong

to companies which specialise in precast

(right), and Silvio Ferarris, CEO of ReMaCon

construction. Aimed at construction-

Products. Jahn’s mid-September visit

industry executives and distributed world-

coincided with bauma AFRICA 2013, and

wide, this highly regarded publication forges

besides representing BFT INTERNATIONAL

a link between building materials machinery/

at the exhibition, he also visited some of

suppliers and precast plants, and provides

the CMA’s producer member companies.

a platform for the international exchange

BFT INTERNATIONAL is a trade journal which, for more than seven decades, has

PRECAST VOLUME 7 • ISSUE 3 • 2013

of scientific discoveries and innovative concrete-related technology.

NEWS

5

Lafarge’s Witfontein Quarry hosts Knysna retirees Lafarge South Africa’s Witfontein Quarry

construction of housing that is more

hosted a group of visitors from the Knysna

compact, durable and beautiful, in cities

branch of the University of the Third

that are better connected by road, rail

Age (U3A) on 23 August. U3A is an active

and air. This same expertise will also

group of retirees which has been running

improve the development of rural towns

a series of monthly geology lectures

and villages.

in conjunction with f ield excur sions.

An early Arbour Day celebration was

Witfontein Quarry is of particular geo-

combined with the U3A visit and involved

logical interest and the visitors were keen

the plan ting o f indigenous tr e e s a t

to examine its rock formations.

the quarry entrance. In addition, as a

L a f ar ge South A f rica is the local

donation towards the local Graaff-Reinet

subsidiary of the international Lafarge

and Districts Cancer Association’s ‘Pink

Group, a world leader in building materials

Trees for Pauline’ initiative, the Quarry

and an industry leader in sustainable

purchased 50 metres of pink fabric to

development. All of the Group’s quarries

wrap around the trees.

have active rehabilitation and biodiversity

“We were delighted to give something

conser vation programmes. It was

back to the senior members of our lo-

explained to the visitors how the quarry

cal community,” says Lafarge’s Stewart

p la y s a k e y r o l e in L a f ar g e’s gl ob al

Chislett, Witfontein Quarry Manager. “The

drive to provide solutions for Building

enthusiastic interest of the visitors con-

Better Cities, solutions that help the

tributed to an enjoyable day for everyone.”

Lafarge’s Witfontein Quarry, where Knysna’s U3A branch assisted wrapping trees in pink fabric to support the local CANSA ‘Pink Trees for Pauline’ initiative.

ARTICLE

7

BLUE ROUTE mall – a green guide for responsible urban development South Africa’s largest sustainable urban drainage system (SUDS) and permeable paving project to date was completed in August at Blue Route Mall, a new shopping centre in Tokai, Cape Town. Spanning some 45 000m² of combined parking and drainage area, the development complies with the City’s Management of Urban Stormwater Impacts Policy which aims to reduce the negative impact of impermeable surfaces on aquatic eco systems.

These measures are referred to in the Policy

but upsets the delicate balance of aquatic

as Best Management Practices (BMPs)

eco systems in natural water courses

and they fall into two groups, structural

such as rivers, streams and vleis, and

controls and non-structural controls.

unless remedial action is taken to reverse

The top layer of Inbitex® sheeting is laid at Blue Route Mall.

According to Martin Thompson, Cape

this process, the absorption, attenuation

Town’s head of Stormwater Catchment

and quality improvement associated with

Planning (South Peninsula), the primary

natural run-off are lost. Permeable paving

reason for the deterioration of urban water

is one of the structural controls we employ

is the disruption of the natural water cycle.

to maintain or mimic these natural flow

“Over the past decade Cape Town has

systems and prevent the wash-of f of

12- 18 month environmental analysis and

experienced unprecedented development

urban pollutants into receiving waters,”

Blue Route’s developers, Fountainhead

both in greenfield areas and in existing

says Thompson.

Trust, were not able to wait that long.

Some of the completed paved surfaces at Blue Route Mall which clearly show the voids between the pavers.

developed/ brownfield areas. Urban

Other structural controls such as green

In the end permeable paving proved the

surfaces, such as roads, pavements, parking

roofs, sand filters, swales, soak-aways

most cost-effective option, in achieving a

lots and roofing have been traditionally

and retention ponds could have been used

functional sustainable stormwater system.

impermeable and these surfaces increase

to treat water-borne pollutants and to

“One o f the gr e a t ad v an t age s o f

the volume of stormwater run-off and the

control egress into the city’s stormwater

permeable paving is that it uses the

accumulation of pollutants in rain water.

drainage system at Blue Route Mall.

same space as open parking areas, unlike

Impermeable surfaces also increase the

According to sustainable stormwater

swales and attenuation ponds which

systems consultant, Peter Wium, swales

require a dedicated single-purpose space.

“Increasing urbanisation not only places

were considered as an alternative solution

And besides controlling water flows into

pressure on existing stormwater drainage

but this option would have required a

stormwater drainage and rivers, in this

likelihood of flooding during heavy rainfall.

PRECAST VOLUME 7 • ISSUE 3 • 2013

8

ARTICLE

case the Keysers River north of the Mall,

Formpave Aquaflow Permeable Paving SUDS

indents so that when they are laid, voids

permeable paving reservoirs also remove

system which has been used successfully

of ±8mm are created between the pavers.

pollutants from the water,” says Wium.

for the past 20 years and is officially

These gaps allow large volumes of water

A full geotechnical investigation was

recognised by the City of Cape Town. The

to infiltrate into the permeable paving res-

under taken by consulting engineer s,

City Council insisted that the permeable

ervoir. This means that even during heavy

Aurecon, to determine the permeability of

paving surface be designed with low spots

downpours there is no puddle formation.

the soil and which permeable paving option

so that if water ponding occurred in these

Blue Route Mall’s permeable paving res-

would be the most suitable. It entailed

areas it would indicate clogged joints which

ervoir was designed to have an absorption

measuring the level of the water table -

needed cleaning. Moreover, part of the

of 4 500mm per square metre per hour

which should be at least 400mm below

Council’s SUDS policy requirement was an

after 10 years, however, the rate was

the lowest stone layer for a successful

80% reduction of suspended solids and a

double that immediately after installation.

permeable paving installation - as well

45% reduction of total phosphorus. The

as establishing the ratio of permeable to

Aquaflow system easily achieves this.

The paving blocks were manufactured locally under license to Formpave which

impermeable surfaces. In the end a ratio

“This is where the Formpave permeable

of 2.5 non-permeable surfaces to one

paving system is very reliable as its water

permeable surface was adopted.

purifying attributes are well established. It

The paver used at Blue Route Mall is

A s an ticip a t e d, a dual sy st em o f

is not only tried and tested in the United

the Aquaflow 200 x 100 x 80 standard

infiltration and egress proved to be the

Kingdom, but has been used successfully

rectangular concrete block in two colours.

most viable permeable paving solution for

on all 43 permeable paving installations in

Rated at 45MPa wet crushing strength, it

the Blue Route development. It involves

the Western Cape,” says Wium.

complies with SANS 1058 : 2010 Concrete

manufactures the blocks for permeable paving SUDS applications in the UK.

some drainage into the ground and the

Permeable paving systems comprise

Paving Blocks. SANS 1083 :2006 Aggre-

discharge of residual water through small

several layers of aggregate which are

gates from Natural Sources is the stand-

diameter pipes into a small tributary of the

topped with concrete block pavers (CBP)

ard specification for the aggregates used.

Keyser’s River.

either for vehicle or pedestrian traffic.

The reservoir or sub-paving material at

The project’s non-permeable surfaces

However, unlike conventional pavers which

Blue Route Mall is optimised to satisfy the

include the Mall’s roof and the immediate

are designed to prevent water infiltrating

Council’s Policy and comprises the following

perimeter of the building, including the

beneath the paved surface, permeable

(see diagram): a layer of Inbitex® geotex-

p ar k ing and pedestr ian ar eas abo v e

paving is designed to do just the opposite.

tile sheeting on the sub-grade; 250mm of

the parking basements. A por tion of

The paving blocks are cast with lateral

clean 53-19mm single-sized crushed stone;

the non-permeable run-off is channelled

100mm of clean single-sized 19-9.5mm

into the permeable paving reservoir and

crushed stone; a second layer of Inbitex®;

the remainder drains into the municipal

a 50mm course of 6mm bedding aggregate;

stormwater drainage via a water channel.

the pavers; and finally a 2,36mm (nominal

Using this method, neither the reservoir

size) crushed stone grit for surface dressing.

nor the stormwater drainage system will

The sub-grade was excavated to provide

be overloaded.

a minimum fall of 1:1000 to fin drain outlets

The design of the Blue Route permeable paving system was also handled by Aurecon, with Wium’s input. It was based on the UK’s

and was compacted as necessary to A close-up view of the permeable paving surface at Blue Route Mall

achieve a G7 Selected Sub Grade layer with a minimum Californian Bearing Ratio (CBR) of 15%. All soft areas were removed and filled with suitable replacement material to provide a stable sub-grade.

The lower layer of sub-base material was installed in two separate layers. Each was compacted with a roller until aggregate ‘lock-up’ was achieved.

The role played by the Inbitex® sheeting is to filter out or ‘devour’ pollutants using microbes which establish themselves soon after installation. The microbes prevent the Inbitex® from clogging up with pollutants.

Blue Route Mall’s Inbitex® was laid with 300mm overlapping joints using double– sided tape to ensure that all the water is

An aerial view of the 45 000m² permeable paving SUDS site at Cape Town’s Blue Route Mall.

PRECAST VOLUME 7 • ISSUE 3 • 2013

filtered by the Inbitex®.

ARTICLE

9

Wium says one of the biggest challenges

the upper voids, the bedding stone and

or expensive and if undertaken regularly, will

with any permeable paving SUDS system

top layer of Inbitex® sheeting may be

certainly extend the system’s functional

is maintenance.

clogged. In such instances a more radical

life,” concludes Wium.

“The site is being inspected frequently

maintenance process, such as replacing

Civil contractors, Martin and East,

to ensur e its pr oper f unc tion, a

the Inbitex® and some of the bedding

were responsible for the earthworks and

process which began immediately after

aggregate, would be required.

the construction of the permeable paving

construction. Par ticular attention is

Generally, maintenance is not onerous

being paid to open the channels and the down-pipes discharging onto the paved surface, as sand, which is easily carried in suspension, can clog the gaps between the pavers. This occurs in the top 1cm of the grit dressing and regular hard brushing is required to ensure that water can get through.

“B e si d e s r e g u l a r b r u sh i n g, m o r e vigorous cleaning will take place twice a year. This will involve conventional street sweepers with vacuum cleaners, brushes, water, and low-pressure hosing where necessary. And we have recommended the removal of pavers for inspection every five years in areas we identify as being more clog-prone. In the worst case scenario,

Blue Route Mall’s permeable paving layers.

installation.

10

ARTICLE

Textured concrete panelling graces the western core of No.1 Silo.

Some of No.1 Silo’s textured panelling clearly demonstrating the aesthetic attributes of precast concrete.

This photo demonstrates how the corbels rest on the ledges. The dowels which lock the corbels into position can be clearly seen protruding from the ledge in the foreground. And next to them the HDPE shims which are used to align the panels are also visible.

PRECAST CONCRETE PANELS ADD LUSTRE TO GREEN WATERFRONT OFFICE DEVELOPMENT Over 1 000m² of precast concrete panelling has been used to clad a section of the external façade of No.1 Silo, South Africa’s latest and largest green office building. Completed in September at Cape Town’s V&A Waterfront and spanning 18 000m², it is also one of Africa’s most advanced sustainable buildings.

Services and Rational Fire Engineers) Col-

Incorporating numerous green-design

(CMA) member, Concrete Units.

laboration (Interiors Architects) Most of the development was clad with double glazing, automatically controlled blinds which track the sun, and an external single-glazed skin. The blinds prevent unwanted heat gain and control solar glare

Smooth-face concrete panelling on the western aspect of No.1 Silo nears completion.

and the double-glazing prevents radiant heat loss or gain and maximises views and natural light throughout the building.

The panelling was supplied and installed

by Concrete Manufacturers Association

attributes, recycled waste and heat, the

According to architect Karien Trengove,

use of seawater in the cooling plant, and

of VDMMA, the panelling was specified to

a roof garden, to name a few, it is one of

dress 280mm masonry cavity walls on the

only two buildings to have been awarded a

building’s two service cores and western

six-star design rating by the Green Building

façade, and to distinguish them from the

Council of South Africa.

glazed façade of the atrium and office

Developed by the V& A Waterfront,

floors. Both textured and flat panels were

No.1 Silo’s architectural team comprised

specified for aesthetic reasons and to give

Van der Merwe Miszewski Architects

different functions unique identities.

A textured concrete panel is lowered carefully into position on the northern aspect of No.1 Silo.

± 128m² and the west core 738m². They

(VDMMA) in association with Rick Brown

One hundred and eighty concrete panel

were manufactured in 17 dimensions, the

& Associates. Other members of the

sections, 120mm thick, were supplied by

smallest spanning 1 590 x 1 750mm and

consulting team included Mace (Project

Concrete Units, 132 with textured (Reckli

the largest extending to 1 705 x 4 295mm.

Managers), MLC (Quantity Surveyors),

Tigris) façades and 48 in flat smooth-face

The smooth-face panels were supplied in

Sutherland Consulting Engineers (Struc-

finishes. The former were used on the

eight sizes and clad a ± 320m² directional

tural Engineers), ARUP (Façade, Wet

service cores - the east core measuring

wall on the western façade. The largest

PRECAST VOLUME 7 • ISSUE 3 • 2013

ARTICLE

11

measured 2 650 x 3 760mm and weighed

panel. Designed to be epoxied into the

lock the corbels permanently into position

3.4 tons. Smaller smooth panels were also

guides of the panels below they provided

after the grouting had been completed

used at the base of the west core to create

a vertical connection between each panel

and they also acted as guiding pins during

a plinth line at ground level.

and facilitated continuity through the panel

installation. High density polyethylene

joints, thereby transferring wind loads to

(HDPE) shims, wedged between the floor

the corbels at each level.

ledge and the corbels, were used to ensure

Structural engineer, Justin Arendse, of Sutherland Consulting Engineers, said a combination of steel sub-frames, corbels

Two further dowels, 20mm in diameter

and dowels were used to anchor the individu-

and also galvanised, were cast into the

al panels to either the façade sub-structure

supporting ledge and epoxied into the

Trengove added that in keeping with the

or the protruding concrete slab edges.

panel corbels. Their prime function was to

design ethos of the building, the overall

that the panels were perfectly aligned before grouting took place.

“Each panel was lowered from the roof

carbon footprints of the panels were re-

into position using a purpose-made six ton

duced through the manufacturing process.

crane and a four-man cage. The reason for

“They were produced using recycled

this was that the project’s tower crane

reinforcing and a slag-waste cement

had a maximum lifting capacity of only one

extender sourced from the Saldanha steel

ton at the end of its reach. Lifting and

mills. Once the moulds were stripped the

then lowering the sections into position

panels were tilted into a vertical position

required meticulous care and coordination

and then stored on an A-frame steel rack

between the cage team and the crane

before delivery to site.

operator and on average only three panels

“Far from being dull and boring this

could be installed each working day,” com-

panelling demonstrates how, when cor-

mented Arendse.

rectly designed and applied, concrete

Two 12mm galvanised steel dowels were cast into the bottom end of each

The six-ton crane, which was purpose-made by Concrete Units to lift the panels into position.

facades can be extremely attractive,” says Trengove.

12

COVER STORY

The pre-heater tower and raw-meal silo at Agangang.

Sephaku’s clinker silos at Delmas.

NEW SEPHAKU PLANT ON TRACK The construction of Sephaku Cement’s 155 ton-per-hour cement milling plant, located to the south west of Delmas in Mpumalanga, is on track to begin production in early 2014. Sephaku engineering project manager, Heinrich de Beer, reports that 90% of the structural steel work which first broke ground in June 2011, has been completed and that the installation of mechanical and electrical equipment is in progress.

“This project incorporates the latest

as planned,” explains de Beer.

Non-production buildings currently in progress at the Sephaku Delmas plant include a clinic, fire station, petrol station, administration building, canteen and guard house.

Referring to the construction of Sephaku Cement’s flagship plant in Lichtenburg, Aganang, de Beer said that a recent highlight was the turning of the kiln for the

environmentally-friendly technology with

Blowers and compressors have been in-

particular emphasis on high efficiencies and

stalled at the fly ash offloading yard and the

first time through the drive unit.

“To date 393 306m³ of earth has been

reduced power consumption,” says de Beer.

extraction system, aeration equipment and

excavated and 72 762m³ of concrete has

Concr ete totalling 35 452m3 and

air slides inside the silos have been installed.

been poured at Aganang. Moreover, 7 700

3 500 tons of reinforcing steel have been

Commenting on the plant’s non-turnkey

tons of reinforcing steel has been used,

used to date. Some of the turnkey project

projects, de Beer says one of the major

15km of earthing cable placed, and 12km

milestones include the completion of a

milestones is the comple tion o f the

of cable trays installed.

30 000 ton clinker silo and the space frame

electrical switch yard and the cabling which

for its roof. Gantry structures, which

runs between it and the main substation.

include sheeting, cabling and lighting, have

“Another is the space-frame structure

been built and so have the stacker and

for the packing warehouse which has also

gypsum store space-frame.

been built. This impressive structure is

“The assembly and installation of the

similar to the roof structure at Beijing’s

Loesche cement mill and classifier, which

airport. The sheeting, which illustrates the

is the heart of the plant, is 90% complete.

size of the warehouse, is almost done and

In addition, electrical cabling throughout

the sheeting which covers the packing plant

the plant is well advanced and proceeding

is likewise close to completion,” he says.

PRECAST VOLUME 7 • ISSUE 3 • 2013

The cement proportioning plant at Delmas.

WE DIDN’T LIST HIS COMPANY ON THE STOCK EXCHANGE We didn’t double his business in the first year We didn’t find him trustworthy employees We didn’t teach him how to build solid structures

WE DID MAKE THE CEMENT HE BUILT HIS REPUTATION ON CREATING POSSIBILITIES

With the planet as one of our core values, we assess the carbon footprint of each and every one of our operations and products while actively striving to drive down our impact on the environment.

www.afrisam.com

14

ARTICLE

with a smooth soffit which can be painted.”

S u p p l i e d b y C M A m e m b e r, E c h o Prestress, the hollow-core slabs in use at The William vary between 3.5m and 6m in length and are supplied in three depths, 120mm, 150mm and 170mm. These were specified at the outset by the structural engineers, based on loading requirements.

“We are using a conventional precast concrete brick at The William which is supplied by CMA member, Savanna Bricks and Paving. Savanna maintains strict quality controls and delivers an extremely reliable product. We work to a minimum strength rating of 10MPa on our developments and we are averaging 12/13MPa with Savanna.

“What we like in particular is that the Savanna bricks don’t vary in size. This means they are easy to lay and plaster.

Prestressed hollow-core slabs supplied by Echo Prestress.

PRECAST CONCRETE PREDOMINATES AT ‘THE WILLIAM’

Some of the other brick suppliers we have used in the past have given us a product which varies in size and strength ratings.

“We are also realising substantial time and cost savings on precast concrete staircases which are being supplied to us

by Specialist Precast Erections (SPE).

The concrete block pavers, which include a 60mm interlocking block and a 60mm bevelled block are being supplied by CMA member, Cast Industries. The latter are being used for the paths and decorative road edgings and the interlockers are being

Concrete bricks, prestressed hollow-core slabs and concrete staircases are some of the precast concrete elements being used to construct 110 eight-unit apartment blocks at The William, a middle-income high-density residential development currently under construction in northern Johannesburg. Other precast concrete products being used include paving blocks, retaining wall blocks, L beams and lintels.

deployed on the roadways,” added Gray.

Each apartment block comprises four

the budget and to ultimately ensure the

(internal electrical); and Rawlins Wales and

storeys which include two three-bedroom

financial viability of the project.

Partners (external electrical).

ground floor units, two two-bedroom units

“Using precast concrete elements

on the first and second floors, and three

assists us with this process in several

one bedroom units on the third floor. The

ways, but maintaining the programme

smallest one covers 40m² and the three-

and ensuring quality are key factors. Take

bedroomed units are 110m² each.

precast hollow-core flooring slabs by way

“Precast concrete is what makes this type

of example; they offer fantastic quality and

of development viable for us,” says Rodney

high standards of finish, and far outweigh

Gray,managing director of Balwin Properties.

in-situ or beam-and-block flooring, which

“We operate in a very competitive

and the entire development is due for completion at the end o f 2015. T he professional team includes: Cimato Moroldo Architects Inc.; Kantey and Templer, civil and structural engineers; Topack Electrical

take weeks to complete.

environment and from the moment we

“Slabs, by contrast, require only a

move on site the clock starts ticking.

matter of hours to install. Thereafter,

It is imperative that we maintain our

grouting and masonry work can begin

programme to ensure we don’t overrun

almost immediately. Moreover, slabs come

PRECAST VOLUME 7 • ISSUE 3 • 2013

The William is being built in six main phases. Construction began in May 2012

One of hundreds of precast staircases supplied by SPE.

16

ARTICLE

CONCRETE BLOCK PAVING CHOSEN FOR PIETERMARITZBURG URBAN RENEWAL PROJECT The City of Pietermaritzburg specified concrete block paving (CBP) as a crucial element in its urban renewal project (PURP) in and around its city hall and other historic structures. The upgrade formed part of an initiative to mark the city’s 175th year .

Financed by the Department of Corporate

determinant in the choice of CBP. “Besides their superior load carrying capacity, concrete pavers were chosen

pavers were tested to ensure that they met long-term (20-year) performance and endurance criteria.

because their life cycle and replacement

In addition to supplying the paving blocks,

costs were not only considerably lower

Brickcast in association with Cristatus

than the other materials surveyed, but

Investments, was also responsible for the

were much easier to replace. Loading was

earthworks, the laying of the sub-base, the

important because Chief Albert Luthuli and

new curbing and new pavements.

Burger Streets, which run parallel to each

The sub-base material comprised: two

other, form alternative routes to the N3 in

150mm layers of G7 aggregate: 150mm of

the event of temporary closure.

stabilised C4 aggregate; 150mm of C2 sta-

G o v e r n a n c e a n d Tr a d i t i o n a l A f f a i r s

“CBP requires far less maintenance

(COGTA), the first phase of the renewal

than asphalt and we’ve also installed

Rossouw says the installation of the

project entailed paving ± 2 400m² of

additional cable ducts for electricity and

new paved sections was complicated by

road comprising: a section of Chief Albert

fibre optics so that the pavers won’t have

the fact that several of the underground

Luthuli Street (formerly Commissioner St)

to be lifted for some considerable time.”

service pipes and cable had to be relocated.

bilised sub-base; and 20mm of bedding sand.

which runs between Church Street and

The road-surfacing pavers selected for

The paved section of Chief Albert Luthuli

Langalibalele Street (formerly Longmarket

the project were 80mm Roadliners cast

Street was earmarked by City officials as

St); the intersection of Chief Albert Luthuli

with a 5mm red topping material to blend

a public gathering place and some of the

and Langalibalele Streets; and a section of

with the red brick of the City Hall and the

175 -year celebrations will be staged there

Langalibalele Street.

Tatham Art Gallery. Rated at 38MPa,

during November.

PURP also entailed the installation

they were manufactured by CMA member,

of new street lighting, new pavements,

Brickcast Industries. However, before

concrete curbing and pavement furniture,

they were specified by Hatch Goba, the

as well as the upgrading of other sections of roads in the precinct. Moreover, parking and new signage initiatives were rolled out in tandem with the paving project.

Iyer Urban Design and Architects was appointed by the City to examine various street scapes and the company identified enhancement materials which would match the city environment and integrate with a proposed bus rapid transport system (BRT).

Iyer and consulting engineers, Hatch Goba, also r esear ched various r oadsurfacing options including clay pavers and coloured asphalt before opting for concrete block pavers.

According to PURP project manager, Gaillard Rossouw, of Hatch Goba, life-cycle costs, aesthetics and loading were of particular concern, the latter proving a key

PRECAST VOLUME 7 • ISSUE 3 • 2013

The partially completed sub-base at Albert Luthuli Street, Pietermaritzburg, prior to the laying of 80mm concrete block pavers.

18

ARTICLE

SWAZILAND OPTS FOR PATENTED PRECAST CONCRETE BARRIER SYSTEM

A worker smooths the concrete in a barrier mould.

Safer roads, prevention of cross-over accidents, a system which meets local and international safety standards with an H2 containment level, plus the long-term benefits of reduced maintenance issues and costs - some of the reasons why the Swazi Government chose the internationally patented Delta Bloc vehicle restraint system for a 13.5km stretch of dual carriageway currently under construction between Manzini and the Kingdom’s new Sikhuphe international airport.

Together with donor consulting f irm

casting. Delta Bloc South Africa monitors

Sadeem al Kuwait from Kuwait, local

the quality of manufacture daily to ensure

designers, Swaziland Consulting Engineers

compliance with DBI’s standards.

(SCE), specified DB100S barriers designed

Steel reinforced, the barriers attain

by Austria’s Delta Bloc International (DBI)

a strength of 30MPa when cured. The

to meet the international median barrier

correct spacing between the rebar and

standards required for the project. DBI

the mould walls is achieved by the insertion

subsidiary and Concrete Manufacturing

of cover blocks. Four cubic metres of

Association member, Delta Bloc South

concrete is poured into the moulds which

Africa, is supplying the barriers.

are inverted for the pouring process.

Manufacturing is taking place in Swa-

During pouring, which takes place in two

ziland under a project license agreement

stages, the moulds are vibrated to avoid

between Delta Bloc South Africa and

honeycombing.

A void former is removed before the mould is turned upright.

Inyatsi Construction. The barriers, with

After the first stage, void-formers are

a containment level of H2, meet both the

inserted into the moulds to create three

local SANS 51317 and European EN1317

lateral rain water drainage channels as well

Completed barriers prior to installation.

vehicle restraint system standards.

as a central channel which runs the full

to release the concrete elements as it

To be awarded the European standard,

length of each barrier. The latter has no

reduces the possibility of damage to the

barriers have to be physically crash-tested

other function other than weight reduction.

still green concrete.

in a road research laboratory. The test

This is achieved without any reduction in

involves a 13 ton truck or bus travelling at

strength or performance.

Installation of the barriers will begin in late 2013 and will be completed in early

a speed of 70km impacting the barrier sys-

After curing overnight, the barriers

tem at an angle of 20 degrees. The amount

reach a strength of approximately 7MPa.

the barrier system deflects whilst contain-

This is suf ficient to remove the void-

Delta Bloc South Af rica managing

ing the errant vehicle is then measured,

formers and to turn the moulds 180º

director, Garth Strong, says that precast

giving the working width of the system.

2014 once the construction of the road surface has been finalised.

into the upright position. The barriers

concrete barriers perform a vital road-

DB100S barriers are six metres long,

can then be separated from the moulds

safety function. “They prevent high-speed

1m high and weigh 4.5 tons. Eight steel

using hydraulic jacks and special press-out

head-on collisions and pay for themselves

D el t a Blo c moulds manu f ac tur e d by

components placed inside the moulds. This

many times over by limiting injury, fatalities

Formquip in Midrand are being used for the

is preferable to shock loading the moulds

and extensive damage to vehicles.”

PRECAST VOLUME 7 • ISSUE 3 • 2013

20

ARTICLE

MAMMOTH PRECAST CONCRETE CULVERTS CHOSEN FOR TWEEFONTEIN STACKER TUNNELS Eight hundred giant precast concrete culverts, three-and-half metres high and just over five metres wide, are being used for the construction of two coal-buffer (stockpile) tunnels at Glencore’s Tweefontein Optimisation Project near Witbank.

transportation by road. To make up the shortfall, the foundations include elevated uprights measuring 500mm. Once in place the joints between the culverts are sealed with bitumastic sealant on the outside and grout on the inner joints.

“Given the culver ts’ non-standard dimensions, six custom-made steel moulds are being used for the casting, which is done horizontally. The moulds were designed and supplied by local steel fabricating company, Mario Meano Engineering. During casting, seven steel 200 x 200mm utility plates are inserted into the inner walls of each culvert. These are being used as attachment points for channelling electrical cabling and piping through the tunnels. Once cured, the culverts are loaded horizontally onto low-bed trucks, each truck carrying two culverts.

“The simple and safe handling of the culverts, both at the Brakpan plant and at the colliery also required some additional engineering. Steel lifting beams were designed by Groenewald. Rather than using

In ter na tional c onsul ting engine er ing

engineer, A r thur Oosthuizen, r ecent

additional machinery to shift the culverts

c o n c e r n, D R A M i n e r a l P r o j e c t s, i s

durability and maintenance concerns with

into a vertical position on site, Groenewald

responsible for the engineering, project

steel tunnels and time constraints with

adopted an innovative approach by using

management and construction work. DRA

in-situ concrete construction prompted

the force of gravity. This is done by at-

is also handling the design of the system

the decision to opt for precast concrete.

taching a steel beam to the top end of

in collaboration with civil and structural

“Although the precast concrete approach

the culvert and then by simply lifting this

consulting engineering company, Holley and

is as yet untested in this type of application,

end with a crane, the culvert swings into

Associates. Wilson Bailey Holmes is the

we believe it will become our default choice on

a vertical position. It is then easily raised

main civil and earthworks subcontractor.

future projects,” says Oosthuizen.

and placed into position on the foundation.

This is the first time DRA has used

Weighing 12.8 tons each, these are some

concr ete cul ver ts f or coal stock pile

of the largest culverts ever made in South

tunnels. Steel and in-situ concrete were

Africa and could well be the largest single

also considered. According to DRA project

culvert order ever. Manufactured by Concrete Manufacturers Association (CMA), member, Aveng Manufacturing Infraset, and designed by technical marketing manager, Coenraad Groenewald, they were produced at its Brakpan manufacturing facility.

“The units are comprised of solid steelreinforced concrete and are designed to handle well in excess of the maximum 20 ton loading they are likely to encounter at the Tweefontein buffer zones,” says Groenewald. “Each contains 600kg of reinf orced steel and measures 3.5m (height) x 5.3m (width) x 1m (depth). The walls are tapered, measuring 350mm at

A 12.8 ton culvert is moved into position prior to installation on one of the four buffer tunnels at Tweefontein Optimisation Project.

PRECAST VOLUME 7 • ISSUE 3 • 2013

the upper end and 300mm at the base.”

The initial requirement was for a height of 4.7m but this proved too large for

Partially completed buffer tunnels.

advertorial

21

PMSA confident of further growth following successful bauma campaign Pan Mixers South Africa (PMSA) has consolidated its reputation as the largest supplier of concrete brick, block and paving-making machinery and technology in Africa - following a highly successful display at bauma AFRICA 2013.

names in the African construction and mining sectors.

“The event provided PMSA management an opportunity of networking with new and existing clients in an informal yet professional environment.”

Booysen noted further that the global trend of automation is taking hold in South Africa.

PMSA marketing and sales manager Quintin

“Our ongoing labour unrest and rising

Booysen says the company’s indoor and

labour costs make automation an increas-

outdoor displays at bauma, showcased a

ingly attractive option,” he says.

comprehensive concrete technology and

L o ok ing ahe ad B o oy sen said tha t

solutions offering, which was well-received

PMSA’s strategic imperatives in 2014

by thousands of visitors.

would include monthly industry-specific

“Outdoor exhibits included a Fiori

open training and workshop sessions at

self-loading concrete batching vehicle,

PMSA’s showroom and sales facility in Jet

automated RE600 concrete brick and

Park, Boksburg.

block making machines, a wide range of HTC

“These sessions will include input from

floor grinding and polishing machinery and

concrete industry experts drawn from

accessories, and live polishing and grinding

Africa and Europe,” he concluded.

demonstrations,” he explains.

PMSA hosted 15 of its international and local suppliers at the event including five

Call 011 578 8700 or email Quintin@ panmixers.co.za for more information on the 2014 training and workshop sessions.

new suppliers. Their representatives were on-hand at PMSA’s indoor stand throughout the exhibition. The new suppliers included: • IMER: An international leader in concrete

batching and mixing equipment

• RAMPF: A specialist in precision block,

brick and paving making moulds

• ABECE: An expert manufacturer of

concrete roof tiling systems

• Turbosol: A pumping technology provider

for the building industry

• Pavatile: An award winning wet-cast

simulated stone mould manufacturer

and supplier Booysen revealed that bauma enabled

PMSA to achieve significant brand building awareness with some of the leading

PRECAST VOLUME 7 • ISSUE 3 • 2013

22

ARTICLE

CMA WELCOMES NEW MEMBERS Since welcoming eight new members in our last issue a further seven members have joined the Association. They are: ASPASA (Aggregate and Sand Producers Association of South Africa); Afrisam; British Precast Concrete Federatrion; The Concrete Society; Dick King Labs; SARMA (South African Readymix Association); and Savanna Bricks and Paving.

associate members, partners, companies and other bodies. It is dedicated to improving the business environment, both short and long term, for the concrete products industry in Great Britain and Northern Ireland. Members’ interests are continually developed by a committed team with extensive connections in the UK and worldwide.

BPCF works in several areas, including h e a l t h & s a f e t y, p o l i t i c a l l o b b y i n g, sustainability & environment, training, and marketing & events. As well as exhibiting at external events, it also holds its own national expo and conference annually to showcase members products and services.

Our Best Practice Awards celebrate the

Outlined below are brief profiles on some of the new members:

best of industry each year with categories in projects, innovation, health & safety, sustainability, and creativity.

Executive director of British Precast,

AfriSam Black-controlled AfriSam is one of the

Andrew Minson, says: “With over 100

most widely spread cement, aggregate

organisational members at BPCF, broad-

and readymix groups in the southern

ranging alliances, and a knowledgeable team

African region, with operations in South

of professionals, we offer a strong and

Africa, Botswana, Lesotho, Swaziland and Tanzania. The company is a proud Level 2

powerful voice within the whole construction A sand quarry which is run by an ASPASA member.

Broad Based Black Economic Empowerment

industry - both nationally and internationally.

We are pleased to be a part of South Africa’s

(B-BBEE) contributor and has a 62.5

ASPASA

Concrete Manufacturers Association, and

percent interest in Tanzania-based and

T he A ggr ega t e and S and P r o duc er s

hope to build a long and mutually beneficial

listed Tanga Cement Company Limited.

Association of Southern Africa (ASPASA)

partnership together.”

Founded in 1934, AfriSam employs more

is a voluntary membership, private sector,

than 2 000 staff members and has an

producers association. It is run through

annual cement production capacity of

an executive council and managed by a

5.8 million tons, produced from seven

management committee which supports

production facilities and distributed to

and guides a full-time executive director.

customers through strategically-located cement depots.

Although a member of the Chamber of Mines, ASPASA is an independent organisation which represents producers of aggregate and sand.

The Association lobbies national and provincial governments on behalf of its members and liaises with other policymaking and opinion-forming entities and associations, both locally and overseas.

The British Precast pavilion at Ecobuild, the world’s biggest event for sustainable design and construction.

The Concrete Society

Members benefit from a wide range of

The Concrete Society of Southern Africa

services through working committees,

NPC is a non-profit ‘community’ of individuals

especially where individual companies have

(some through their companies) who seek

insufficient resources.

to keep themselves up-to-date with the latest technology and thinking in concrete

The placement of 45t precast antifers on a breakwater at Durban Harbour. AfriSam cement was used for these precast antifers.

PRECAST VOLUME 7 • ISSUE 3 • 2013

British Precast Concrete Federation

an d c o n c r e t e - r e l a t e d m a t t e r s . T h e

British Precast Concrete Federation

Society, through its national and regional

(BPCF) is an industry federation comprising

network, offers seminars, site visits, CPD

concrete product producers and product

accreditation for engineers, publications,

associations, together with a wide range of

student support, excellence awards, and

ARTICLE

creates business opportunities for its individual and corporate members.

23

The company is associated with Moisson Instrumentation which is SANAS ac-

In this way the Society achieves its

credited for handling calibrations in force

overall mission of promoting excellence and

compression, and besides the CMA, Dick

innovation in the design and use of concrete,

King Lab Supplies enjoys membership in

providing a forum for networking and

the following associations: BSI (British

technology transfer between its members

Standards Institution); N.L.A (National

and local and international affiliates.

Laboratory Association); SAFCEC (South African Federation of Civil Engineering Contractors); Sabita (South African Bitumen Association); and the Johannesburg Chamber of Commerce and Industry.

SARMA SARMA (The Southern African Ready-mix Association) is a national body which represents South Africa’s reputable ready-mix companies. It advances premix technology through research and participation, is responsible for promoting the ready-mix industry, and promotes ready-mix as the preferred construction material.

It disseminates information on the

The De Hoop dam under construction.

current and prospective use of ready-mix concrete to its members and interacts

Dick King Lab Supplies

with authorities, suppliers, customers,

Dick King Lab Supplies has been supplying

specifiers and regulators.

ci v il e ngin e e r ing l ab o r a t o r y t e s ting equipment to local and international concerns for approximately 35 years.

Based in South Africa, the company markets its equipment under the Kingtest brand name and manufactures container labs for site use under the brand name Contain-A-Lab. The company also manages several agencies, including: Matest; IPC; Baty; and Proceq Instruments.

A readymix delivery.

It also sets standards and guidelines with regard to environmental, safety and quality issues and SARMA membership requires that these stringent policies are met and adhered to. In addition, members are regularly audited against

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PRECAST VOLUME 7 • ISSUE 3 • 2013

OUR DOOR

IS OPEN BECOME PART OF THE FUTURE

WE INVITE ALL PRECAST CONCRETE MANUFACTURERS TO JOIN US *

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* TERMS AND CONDITIONS APPLY

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CONCRETE MANUFACTURERS ASSOCIATION 16 Horn Street, Kempton Park, 1620 PostNet Suite 8612, Private Bag X32, Kempton Park, 1620 Tel +27 11 805 6742 • Fax +27 86 524 9216 • E-mail: admin@cma.org.za

www.cma.org.za

APPLICATIONS

25

ECHO PRESTRESS builds HIGH-STRENGTH SECURITY WALL CMA member, Echo Prestress has erec-

Easterhuizen advises that soil condi-

ted a security wall built with its own

tions determine the type of foundation re-

prestressed hollow-core concrete slabs

quired for this type of walling and whether

at its prestressed hollow-core factory in

the slab placement should be horizontal

Chloorkop, Gauteng. Constructed in two

or vertical.

sections, the wall is 275m long and 5,4m

“Clay, collapsible soils, high water tables

high at its highest point. A 0,6m section

and so on require horizontal installations,

of the wall is buried below ground.

whereas better soil conditions are best

The walls comprise five tiers of inter-

suited to vertical applications. Some hori-

locking slabs measuring 6m (length) x 1.2m

zontal placements may also require piling.

(width) x150mm (depth). They were placed

“Wind resistance and stormwater

horizontally and secured into position be-

drainage are other design considerations

tween vertical steel columns.

and so is impact resistance which deter-

Echo Prestress marketing director,

mines maximum wall height and slab depth.

Melinda Esterhuizen, says ther e ar e

Stormwater drainage must be properly

several advantages to this type of wall,

engineered and weep holes, generally 100m

speed of construction, being one of the

in diameter, should be placed strategically

major considerations, cost being another.

for good drainage.

“The current cost of building a security wall using prestressed hollow-core slabs,

Esterhuizen added that precast security walls also have some green attributes.

is approximately half that of an in-situ wall

“The concrete slabs and steel support

offering the same properties; an in-situ

columns are both 100% recyclable and

wall would take two to three times as long

reusable. The wall itself has a very long life

with no advantage gained in strength or

span, is maintenance free, and other than

durability. Moreover, precast walling has

occasional cleaning, no other maintenance

no requirement for shuttering or propping,

is required. However, the steel columns do

onsite curing, formwork or grouting, and

need rust protection.”

the construction rate is approximately 50

Esterhuizen concluded by saying that

linear metres per day (eight hours).” says

a key to the success in constructing

Esterhuizen.

this type of security wall is a very close

T he Echo wall comprises 50MPa

working relationship between the design,

concrete which means even jack hammers

engineering and construction professionals.

would struggle to break through it.

Echo offers design solutions for both

“Intruders cannot scale it, dig under it

precast flooring and security walling

or break through it without making a great

applications. Contact Melinda Esterhuizen

deal of noise and taking a very long time.”

on (011) 589 8800 or 083 605 0077.

A section of recently completed prestressed hollow-core slab walling at the Echo Prestress factory in Chloorkop.

PRECAST VOLUME 7 • ISSUE 3 • 2013

26

APPLICATIONS

AC T0M Air Pollution Control recently completed a turnkey contract for the design, manufacture and commissioning of three high-efficiency bag filters at PPC Cement Slurry’s factory near Mafikeng,

ACTOM executes fast-track dust control contract

North West Province. The installation was

steel and concrete structure, and the

“The short shutdown schedule meant

completed on schedule at the end of April

installation of new bag filters for two new

that the site had to be shared with the

this year with no safety related incidents.

separators. Furthermore, all three filters

other contractors involved in the upgrade,”

The multi-million rand contract, awarded

and associated ducting had to be insulated

Hopkins said.

in May last year, involved the supply of a

and clad during the shutdown phase.

76 000 Am3/hour reverse pulse bag filter to

The main mill bag filter was designed to handle higher dust volumes and all bag filters

replace an electrostatic precipitator (ESP)

were designed to reduce dust emission lev-

at PPC Cement Slurry’s Finishing Mill 4.

els in accordance with the newly legislated

In addition, two bag filters, each with an

2015 environmental emission target of

air moving capacity of 16 000 Am3/hour,

30 mg/Nm3 at high temperatures.

were supplied to de-dust two new high-

Dipeen Dama, PPC’s senior project

efficiency separators that were installed

manager, said ACTOM Air Pollution Control

as part of the upgrade.

implemented all stages of the contract effi-

“One of our challenges was to install

ciently, from design through to installation.

all three bag filters during an eight-week

“Per f ormance testing of the mill-

shutdown period,” said Raymond Hopkins,

bag filter was completed early in July

ACT0M Air Pollution Control’s project

2013. The results of the isokinetic dust

manager on the contract.

sampling measurements confirmed that

“T his involved the dismantling and removing the existing ESP, the installation of a new mill bag filter on the original

the performance of the new mill bag filter The completed 76 000 Am3/hour reverse pulse bag filter at PPC Cement Slurry’s finishing mill 4 near Mafikeng.

met the contractual guarantee of less than 30 mg/Nm3,” he commented.

AFRISAM ADVISES ON CHEMICAL ADMIXTURES In order to ensure concrete blends which

extender content,” says Di Nardo.

which will also attract two points,” com-

are not comprimised in strength or integ-

Cement extenders are finding increasing

rity, AfriSam supplies several chemical

favour from an environmental perspective

In addition to its environmental benefits,

admixture technologies.

as their use results in a large reduction in

cement produced with ‘green’ extenders

the generation of carbon dioxide.

has no negative effect on concrete quality

According to AfriSam’s Furio Di Nardo, one needs to be aware of the challenges associ-

“AfriSam’s ‘green’ cement utilises ex-

ments Di Nardo.

or workability, durability and density.

tenders such as slagment, fly ash and lime-

“In fact, it enhances the workability of

“Some structures, such as concrete

stone to reduce the amount of clinker needed

fresh concrete and makes the end product

bases, allow for increases in the extender

in the cement. The use of these extender

more durable and impermeable. AfriSam

blend of up to 50% replacement proportions.

materials is a classic example of recycling at

will continue to drive research in the use

However, we caution that with more intri-

its best, since most of the material would

of secondary products in green cement

cate structures like floors, surface beds or

end up in landfills,” says Di Nardo.

mixtures as a catalyst for environmental

ated with increasing the extender content.

pavements, one should reduce the extender

The Green Building Council of South

blend to minimise the potential for cracking

A f r ic a (GB C S A ) r ecen tl y r e f ined i ts

and curling. In these instances, an advanced

three-point requirements in lowering

knowledge of curing is a prerequisite.”

concrete’s environmental impact in building

As pressure increases for the construc-

construction. To this end AfriSam has paid

tion industry to reduce carbon footprints,

close attention to the ingredients used in

it is critical that the limitations of concrete

concrete on various building projects.

with added extenders be reviewed carefully.

“An example is Standard Bank’s cus-

“AfriSam has invested substantially in

tomer service office in Rosebank, Johan-

researching the performance of extenders

nesburg, which qualified for two GBCSA

and we are now in a strong position to offer

points in the concrete category. We also

concrete mixes with the same properties

designed custom mixes for Nedbank’s

and performance as concrete with less

new Lakeview development in Roodepoort,

PRECAST VOLUME 7 • ISSUE 3 • 2013

stewardship,” Di Nardo concludes.

AfriSam’s ‘green’ cement utilises extenders such as slagment, fly ash and limestone to reduce the amount of clinker needed in the cement.

APPLICATIONS

27

Eco-Tile® Extrusion for a bright housing future A new concrete roof tile extrusion machine, the Eco-Tile Extruder®, manufactured by Jessop & Associates (Pty) Ltd, was exhibited in September at bauma Africa 2013.

According to Grahame Jessop, the founder and managing director of Jessop and Associates, the new machine is capable of producing the same high-quality Double Roman tiles that are made on faster PROTILE® high-speed extrusion plants.

The Eco-Tile Extruder® manufactured by Jessop & Associates.

tile plants and related equipment for nearly

“This means that precision extruded

30 years, having supplied and installed over

concrete roof tiles can now be produced

50 tile plants in 18 African countries and

on a much broader geographic footprint,

many more elsewhere in the world, making

and at a very favourable cost. The Eco-Tile

us Africa’s very own global equipment

Extruder® is capable of extruding tiles

supplier,” said Jessop.

based on the thinner, more cost-effective

The Eco-Tile Extruder® concept drew

range of the SABS quality requirements

much attention at Jessop & Associates’

i.e. 11.0mm thick, and weighing 4.2kg per

bauma Africa 2013 stand. Many CMA

tile or 42kg/m2 roof installed. Normally

members visited the stand, some of whom

low capacity machines struggle to achieve

have been customers for many years.

“We also exhibit regularly at BAUMA in

this quality.

“Our entire range of equipment was

Germany - the largest machinery show of

born and bred right here in South Africa.

this kind in the world - and it has assisted

We have been manufacturing concrete roof

us in growing our PROTILE® brand globally.

Swiss watch technology inspires greater moisture measurement accuracy

The Hydro-Mix VII.

Leading process en-

chutes and holding hoppers, and copes

gineering firm, Birk-

very well with fluctuations in temperature

enmayer, has intro-

without compromising results.

duced the state-of-

With a measurement rate of 25 times

the-ar t Hydr o-Mix

per second and a choice of measurement

VII moisture sensor,

modes for optimised sensor performance

which measures to 0.1% accuracy and is

in a range of applications and material

ideal for the concrete industry. Made by

types, the Hydro-Mix VII is essential for

British moisture measurement technology

accurately controlling water addition

manufacturer, Hydronix, the Hydro-Mix

during the mixing and drying processes.

VII was inspired by the bimetallic strip on

It inter f aces with the Hydr o-Com

mechanical Swiss watches, which remain

software from Hydronix for continuous

indifferent to temperature changes.

monitoring via USB or Ethernet, and is

Building on the success of the existing

extensively supported by Birkenmayer in

Hydronix’ range of moisture measurement

South Africa, as well as by Hydronix’s

devices which is also available locally

global exchange programme.

through Birkenmayer, the Hydro-Mix VII can be fitted flush onto screw conveyors,

For more information on the Hydro-Mix VII, call Birkenmayer at 011 970 3880.

PRECAST VOLUME 7 • ISSUE 3 • 2013

28

CMA MEMBERS

Producer members company name

telephone

PROVINCE

Pillar

A Fick Sementwerke

(022) 913 2370

WC

PB

Aveng Manufacturing Infraset

(011) 876 5500

JHB

PB/PI

Bass Beams

(031) 784 1920

KZN

PB

Bay Brick

(035) 792 5218

KZN

PB

Beta Tiles

002634 2925303

ZIM

PB

Boland Concrete

(021) 875 5365

WC

PB

Bosun Brick Midrand

(011) 310 1176

JHB

PB

Brickbuild t/a Panda

0026 244 2107/8

BOTS

PB/PI

Brickcast Industries cc

(031) 507 5525

KZN

PI

Vaka Concrete (Pty) Ltd

C.E.L. Paving Products

(021) 905 5998

WC

PI

Vanstone Precast (Pty) Ltd

Cast Industries

(011) 316 2375

JHB

PB/PI

Colonial Stone

(011) 794 9737

JHB

PB/PI

Concrete Units

(021) 386 1923 (016) 362 2236

WC/JHB

PB/PI

Conframat

(0861) 33 5599

JHB

PB/PI

Corobrik (Pty) Ltd

(031) 560 3111

KZN

PI

company name

telephone

PROVINCE

Pillar

Rocla

(011) 670 7600

JHB

PB/PI

Savanna Bricks & Paving (Pty) Ltd

(012) 809 1197 086 559 28744

JHB

PB/PI

Shukuma Flooring

(041) 372 1933

EC

PB

Southern Pipeline Contractors

(011) 914 8500

JHB

PB/PI

087 941 3889

JHB

PB/PI

Technicrete

(011) 674 6900

JHB

PB/PI

Topfloor

(021) 951 7700

WC

PB

00263 8644 08100

ZIM

PB/PI

(012) 541 2056/1808

JHB

PI

(011) 851 1098

JHB

PI

Style Decor Design & Manufacturers

West End Cement Bricks

PI - Precast Infrastructure PB - Precast Building

Associate Members telephone

PROVINCE

ASPASA

(011) 791 3327

JHB

ARQ Consulting Engineers

(012) 348 6668

JHB

0044 116 253 6161

UK

company name

Deranco Precast Deranco Blocks Deranco Paving (Pty) Ltd

(041) 933 2755

EC

PB/PI

Eagle Roof Tiles (Pty) Ltd

(044) 874 0290

EC

PB

British Precast Concrete Federation

Echo Prestress (Pty) Ltd

(011) 589 8800/8899

JHB

PB

Concrete Society

(012) 348 5305

JHB

Fastdeck (Pty) Ltd

0026737 71321528

BOTS

PB

ILIFA Africa Engineers (Pty) Ltd

(016) 981 0591

JHB

Inca Concrete Products

(021) 904 1620

WC

PB/PI

JC Paving Consulting

(011) 431 0727

JHB

Inca Masonry (Garden Architecture)

(043) 745 1215

EC

PB/PI

Pipeline Installation Professional Engineering

(012) 644 0043

JHB

082 850 3512 082 442 2082

JHB

PI

Sekhukhune & Associates

(012) 993 4776

JHB

Kwena Concrete Products

00267 3922850

BOTS

PB/PI

SNA Civil & Structural Eng

(012) 842 0000

JHB

Lategan Cement Works

(021) 873 1154

WC

PB

SARMA

(011) 791 3327 086 647 7967

JHB

Marley Roofing

(011) 316 2121

JHB

PB

Terraforce (Pty) Ltd

(021) 465 1907

WC

Mobicast

(044) 874 2268

WC

PB/PI

Tjeka Training Matters

(011) 665 2777

JHB

(011) 222 7300/7408

JHB

PB

Young & Satharia Consulting Civil Engineers

(031) 207 7252

KZN

(012) 386 0050

JHB

PI

Namib Roof Tile Com/t/as Swakop Tiles cc

0061 222 965

NAM

PB

ReMaCon Products cc

011 393 5504

JHB

PI

Revelstone

(0861) 173 835

WC

PB

Reya Pele Bricks Ltd

(016) 363 0340

JHB

PB

Keystone Walling

Monier Roofing South Africa MVA Bricks

PRECAST VOLUME 7 • ISSUE 3 • 2013

cement members telephone

PROVINCE

AfriSam South Africa (Pty) Ltd

(011) 670 5500

JHB

PPC Ltd

(011) 386 9000

JHB

company name

CMA members

29

non-producer members telephone

PROVINCE

Abel Equipment

(044) 874 1876

EC

Ash Resources (Pty) Ltd

(011) 886 6200

Birkenmayer H (Pty) Ltd

telephone

PROVINCE

Manitou SA (Pty) Ltd

(011) 975 7770

JHB

JHB

Mapei SA (Pty) Ltd

(011) 552 8476

JHB

(011) 970 3880

JHB

Pan Mixers SA (Pty) Ltd

(011) 397 3754

JHB

BASF Construction Chemicals South Africa (Pty) Ltd

(011) 203 2400

JHB

Sika South Africa (Pty) Ltd

(031) 792 6500

KZN

Smartstone (Pty) Ltd

(011) 310 1161

JHB

Chryso Southern Africa (Pty) Ltd

(011) 395 9700

JHB

0048 480 369 0811

POL

Delta Bloc South Africa (Pty) Ltd

(011) 024 4604

JHB

(021) 535 4455

WC

Dick King Lab Supplies

(011) 499 9400

JHB

00264 61 213 632

NAM

Kaytech

(031) 717 2300

KZN

Kerneos Aluminate Technologies

(011) 444 3090

JHB

003111 356 2460

NETH

company name

Kavango Block Brick

company name

Techmatik SA Technical Finishes

CONTRACTOR members company name

Kobra Moulds B.V.

telephone

PROVINCE

Decorton Retaining System

(021) 875 5155

WC

Friction Retaining Structures (Pty) Ltd

(011) 608 4321

JHB

PYW Paving

(031) 903 1736

KZN