CAPE COMPANIES SCORE ELEVEN CMA BUILDING PROJECT AWARDS:

Cape-based precast concrete manufacturers performed exceptionally well in this year’s Concrete Manufacturers Association (CMA) Awards for Excellence competition, capturing eleven awards for the region. The awards were made in the following categories: Concrete Retaining Block (CRB) Walls (three); Concrete Masonry (five); Concrete Block Paving (two); and Suspended Concrete Floor Slabs (one).
 
The aim of the awards is to promote excellence and innovation in the use of precast concrete. It also serves to highlight the significant role that CMA member companies are playing in the provision of educational buildings, access to fresh water, improved sanitation, roads, housing and infrastructural products. The competition is held biennially, this being the 12th since the event was first staged in 1986.

The Cape awards were presented at a ceremony held at the Stellenbosch University Business School on 30th September.

Cape CRB awards comprised the following: House Davidson, Wolseley, an award for Retaining  Walls< 3m high; Suikerbossie Nek, Cape Peninsula, an award for Retaining Walls > 3m high; and Die Kelders Cave Excavation, Walkers Bay Nature Reserve, a Special Commendation award for Retaining Walls > 3m high. Special commendation awards are made in instances where the judges rate two entries in the same sub-category almost equally and both worthy of an award.

Masonry awards went to: Fisherman’s Village, Muizenberg, a Residential A Community Housing award; Mitchells Plain Housing Scheme, Western Cape Peninsula,  a Special Commendation Residential A Community Housing award; Red Location Museum, Port Elizabeth, a Commercial & Community award; Platinum Park, Cape Town, a Factories and Warehouses award; and Islamia College, Cape Town, a Vintage award. Vintage awards are made to worthy projects which are still in their original form and older than 10 years.

The two Concrete Block Paving Awards were taken by: House Haneka, Bishopscourt, Cape Town
with a Residential award; and Croyden Olive Groves, Croyden/Faure, with a Roads award.

The Floor Slab award, which  went to Milkwood Phase 1 in Aston Bay, was in the Residential category.

The judging of this year’s competition, took place in June when over 150 entries in six category groupings were critically assessed by two judging teams over two days at the CMA’ premises in Midrand.

Each team consisted of five judges. All construction-related professionals, they comprised architects, a landscape architect, civil engineers and a quantity surveyor. The judges pored over and debated the merits of this year’s crop of entries with great deliberation and carefully considered comment was given on their selection of winning entries.

CMA director, John Cairns, says that the 10 judges found the overall standard to be high and where the projects were not of a sufficiently high standard, awards were not made. He notes that the awards are based on photographic and written submissions as time and budget constraints preclude actual site visits.

“The competition would carry very little value without the expertise and unbiased input of the professionals who assume the judges’ mantle, and we are extremely grateful to them for giving up a full day of their busy schedules to participate in the event,” says Cairns.

Several innovative products and systems have been introduced by CMA members during the past five years such as The CMA Roofing System, a concrete tile roofing system for affordable housing, and innovative uses for hollow-core slabs. Unlike some of the materials they replace, they are not only affordable, but retain the inherent qualities that precast manufactured concrete provides.

“These products and systems are widely reflected in the entries for this year’s competition and are successfully contributing to improving the quality of life across the board. New product development always has its attendant risks, no less so in this instance, where margins are low and the competition fierce.

“The risks our members have taken have proved more than worth it, and we look forward to the next 10 years, confident that the CMA will continue to initiate products and systems appropriate to the country’s needs,” concludes Cairns.

WESTERN AND EASTERN CAPE REGIONAL AWARD WINNERS
The following Western and Eastern Cape projects gained regional awards and some of them may also win national awards when these are announced on October 11th at a gala dinner at The Theatre on the Track in Kyalami, Johannesburg.

CONCRETE RETAINING BLOCK WALLS
R1-6; R2-7 and R2-9

Caption R1-6

House Davidson – Wolseley
Category – Retaining Wall Elements: retaining walls  < 3m high constructed from concrete retaining blocks.

In 2003, this property was a neglected piece of mountain land with steeply sloping, wattle infested gullies, a lack of potable or irrigation water and no level building platform. An earthworks contractor cleaned out a small pond, built a sizeable water storage dam and cut two building platforms with a view of the valley. A workshop was built on the upper platform and the main house was sited on the lower level.

Three slopes were retained and terraced using Terraforce L12 blocks, and stairs, built with 4 x 4 step blocks, were incorporated into the walls. The blocks provided ideal growing conditions for the garden because they were filled with topsoil and watered with an irrigation system.

Extremely heavy winter rains in 2006 threatened to undercut the sides of a newly built road on the property which was paved with concrete interlocks. To prevent further erosion, Terracrete Hardlawn blocks were installed for lateral support and Terrafix erosion control blocks were used to line sections of various stormwater control channels.

Professional Team
Contractor:  Dassenberg Retaining Systems
Manufacturer: Klapmuts Concrete
Licensor:  Terraforce

Product information
Terraforce L12 and 4 x 4 Step Blocks (Sandstone)
Terrafix 15 and Terracrete (Grey)

Judges’ Comments
The blocks offered a good engineering solution, with the garden and context reflected in the design. The small forms of pocket gardens assisted in retaining an existing tree. The 4 x 4 step blocks and the retaining blocks complemented each other.

Caption R2-7

Suikerbossie Nek – Houtbay
Category – Retaining Wall Elements: retaining walls > 3m high, constructed from concrete retaining block elements.

This retaining wall project began when two engineering firms, Jeffares & Green and Mike van Wieringen and Associates were requested to investigate a cut slope failure at Suikerbossie Nek, situated above Victoria Road between Camps Bay and Hout Bay.

The engineers found that erosion and collapsing were caused by the angle of the slope. Although initially stable in terms of wedge or slip circle failure, over time the slope had been rendered unstable through weathering which reduced its surficial strength parameters. In addition, non-functional surface cut-off drains, situated above the cut face, had accelerated erosion and slip failure. Moreover, a lack of regular maintenance had led to silting and vegetation growth in the drain, resulting in choking with consequential over-topping.

Duncan Murphy, a civil engineer at Jeffares & Green, outlined the nature of the failure: “At some point erosion activity would have intersected the cut-off drain, and a large eroded gully in the cut-face would have been the likely outcome. This could have resulted in the formation of a deep and irreparable gully extending a considerable way up the slope. Moreover, judging by the crack pattern in the head-scarp, a significant collapse onto the road during a period of high rainfall, was imminent.”

Remedial options such as gunite and soil nails or an 8,5m vertical concrete retaining wall were discarded for aesthetic reasons. Instead a combination of a near vertical gabion toe wall up to 2,5m high, a 35º Terrafix covered slope topped with a concrete-lined cut-off drain, and Terraforce L12 side walls, was the option selected.

Terrafix 150 blocks were laid to trap the maximum amount of topsoil on the face, a solution which has prevented erosion and weathering, and encouraged plant growth.
 
Because the slope was large and curved, near-horizontal concrete infill walers were used at five metre intervals to fill the uneven spaces between adjacent panels. These were secured with anchor bars so that any possible pressure on the gabion wall would be reduced, and Terrafixes’ maximum laying density of 10 blocks per square metre was used to prevent lateral sliding.
Thousands of water-wise indigenous plants, ground cover and bulbous species, were planted and these have started to relieve the nondescript appearance of the slope.

Professional Team
Engineer:              Jeffares & Green / Mike van Wieringen and Associates
Contractor:            Dassenberg Retaining Systems
Manufacturer:       Klapmuts Concrete
Lincensor:            Terraforce
 
Product Information
150 Terrafix blocks
Terraforce L12 blocks (Sandstone)

Judges’ Comments
A project visually sensitive to its context. The anchoring wall and landscape planting were well done.
 

Caption R2-9

Die Kelders Cave Excavation – Walkers Bay Nature Reserve, Hermanus
Special Commendation Award
Category – Retaining Wall Elements: retaining walls > 3m high, constructed from concrete retaining block elements.

Die Kelders Cave is one of the Western Cape’s most important cultural assets. Its remains date back to between 65 000 and 85 000 years, when the ocean was situated approximately five kilometres from the cave.

The site was first excavated between 1969 and 1973 and then re-excavated between 1992 and 1995.  Due to  its archaeological and historical significance, a decision was taken to carefully replace sandbags with Terraforce L18 retaining blocks.

The blocks were chosen because their medium size made them suitable for small radii and easier to handle. Great care had to be taken to maintain the integrity of the original excavation and a Terraforce recommended contractor, Cape Wall, was appointed. The consulting engineer, plus a Cape Wall supervisor, and three of the company’s most experienced workers, ensured strict quality control throughout the project.

The logistics of the contract were particularly challenging. Some 2 200 blocks had to be transported by hand down 200 steps, across a boulder strewn beach and through two caves, the first of which was ‘guarded’ by a beehive. Very positive reports on the project were received from members of Heritage Western Cape.

Professional Team
Engineer:  Braam Auret and Associates
Contractor:  Cape Wall
Manufacturer:  Klapmuts Concrete
Licensor:  Terraforce

Project Information
Terraforce L18 and 4 x 4 Step Blocks (Sandstone)

Judges’ Comments
The design looks like the contours of a cave. Middle Stone Age deposits can be excavated from this extremely sensitive site.

CONCRETE MASONRY
M1-1; M1-3; M3-5; M4-2; M5-1

Caption M1-1

Fisherman’s Village – Muizenberg, Western Cape Peninsula

Category – Residential A: community housing.
This 135 unit housing complex comprises single, double and triple story units, which are free standing, semi-detached or attached, and are designed with varied street elevations to enhance the seaside experience.

The single and double storey units were constructed economically using Cape Brick’s Maxi Cement Bricks. Additional architectural interest was created by corbelling the brickwork around the windows and the parapets. Furthermore, the recesses and the stepping of unit elements allowed for the attractive spacing of control joints.

Professional Team
Architect:   Bouwer Architects
Engineer:   Sutherland Associates
Quantity Surveyor:  De Leeuw
Contractor:   Power Construction
Manufacturer:   Cape Brick

Product Information
7MPa Maxi Bricks
14MPa Maxi Bricks

Judges’ Comments
A good application of the product, with aesthetic appeal that creates a positive urban environment.

Caption M1-3

Mitchell’s Plain Housing Scheme – Cape Peninsula

Special Commendation Award
Category – Residential A: community housing.

A total of 1 345 RDP houses in four modules, 31m², 33m², 40m² and 84m², were constructed using an INCA M140 hollow block for this housing project. The block’s thermal properties are NHBRC approved and the outer skin requires no plastering. Internally the walls are flush jointed and waterproofing was achieved with the application of a special coating, manufactured by Tefkin.

The block work is exceptionally neat, with special attention having been paid to eave infill. Moreover, the windows were built with a plastered band surround, adding to the pleasing aesthetics.

Professional Team
Architect:   City of Cape Town
Engineer:   City of Cape Town
Quantity Surveyor:  City of Cape Town
Contractor   Chelnat Novu Civils
Manufacturer:   Inca Concrete Products

Product Information
M140 INCA Concrete Block

Judges’ Comments
The product complies with minimum norms and standards and a Commendation Award was given for the way the product was applied, providing as it does for the needs of the lower-income housing segment.

Caption M3-5

Red Location Museum – Port Elizabeth

Category – Commercial & Community: shopping complexes, office blocks, hotels, parking garages, recreation and entertainment centres, education and training buildings, churches, government and municipal buildings.

At the end of the Anglo Boer War in 1902, the British left a settlement of rusted corrugated iron huts on the outskirts of Port Elizabeth. Over time many black families settled in the area which  became known as Red Location. Owing to some important political and cultural leaders who were raised in the township, Govan Mbeki, John Kani, George Pemba and Raymond Mlaba among them, a decision was taken build a museum.

Red Location Museum is a robust, down-to-earth structure which will endure for many generations.

One of the requirements was for the building materials to blend in with the surrounding structures which consisted mainly of concrete and corrugated iron. The choice fell to Deranco’s grey Hollow Blocks and these were accurately laid in grid-type panel formation to match the concrete columns and other structural elements. On completion the final block work enclosed a large single-volume space.

Professional Team
Architect:   Noero Wolff Architects
Engineer:   De Villiers & Hulme
Quantity Surveyor:  Walters & Simpson
Contractor:   Alfdav Construction in association with SBT Construction (Eastern Cape)
Manufacturer:   Deranco Blocks

Product Information
Hollow Blocks (Grey) 390 x 190 x 90mm
Hollow Blocks (Grey) 190 x 190 x 90mm

Judges’ Comments
This design celebrates the true appreciation of the use of concrete and demonstrates the adaptability of concrete block work, with detailing conforming to the design. It is a landmark building which sets a benchmark in the application of concrete technology. The application of design and materials were technically sound.

Caption M4-2

Platinum Park – Cape Town
Category – Industrial: factories and warehouses.

This business park comprises 160 units of roughly 100m² each. The design brief was to provide a comfortable business environment of timeless design and human scale, and the buildings were modelled on a Cape Vernacular design. The walls were built with Western Granite’s Jumbo Chardonnay Rockface bricks up to eave height . An M90 block was used internally as its metric modular format ties in with the jumbo-sized face brick. In addition, neat, white-plastered reveals surround each window.

Professional Team
Architect:   Creative Architectural Design
Contractor:   Lyndon Projects
Manufacturer:   Western Granite Bricks

Product Information
Jumbo Rockface (Chardonnay) 222 x 90 x 90mm

Judges’ Comments
A well constructed, simple and elegant combination of brick and plaster.

Caption M5-1

Islamia College – Cape Town
Category – Vintage: any masonry product in its original form older than 10 years.

The construction of this school began in 1998 when the first building was built. A second building was completed in 2005, and a boundary wall was erected in 2008.

Western Granite’s Rockface concrete brick was used on all three projects.  The architects chose the brick because of its low maintenance attributes and light colour. They also placed pre-cast decorative panels below the windows in order to break up the large expanse of wall. The brick has performed well during the past 10 years, showing only slight staining from an irrigation spray system.

Professional Team
Architect:   Joshua and Joshua Architects
Civil Engineer:   Orriet Welby
Structural Engineer:  Buddy Sydow
Quantity Surveyor: Nazeem Khan & Associates
Contractor:   Sharief Construction
Manufacturer:   Western Granite Bricks

Product Information
Western Granite Rockface (Champagne)

Judges’ Comments
The building has weathered well and displays the durability of the concrete products applied.

CONCRETE BLOCK PAVING
CAPTION P1-1
House Haneka – Bishopscourt, Cape Town

Special Commendation Award
Category Residential: paving around residential buildings, driveways, footpaths, courtyards, patios and pool decks.

Situated at the back of Table Mountain, this Bishopscourt property underwent a complete rebuild and some major landscaping to ensure that it complemented its immediate surroundings.
 
C.E.L. Paving’s sandstone Vintage pavers and charcoal Cobblestones were selected by the owner for their natural appearance, high dimensional accuracy, random surfacing and proven durability. They were used to frame the driveway and add a modern feel, and to avoid the occurrence of grey haze, no cement was used in the grouting.  Instead, a joint stabilising material ensured a stable but flexible pavement with no staining or loss of grout.

Professional Team
Pavement Designer : Grant Ambrose
Contractor :   SA Paving Cape Town
Manufacturer :   C.E.L. Paving Products

Product Information
Vintage Pavers (Sandstone) 190x125x50mm
Cobbles (Charcoal) 100 x 100mm. Total area: 35 000m²

Judges’ Comments
Attention to detail and aesthetic appeal ensured this product a Special Commendation, as it is a good example of what can be achieved with dry-casting.

 
Caption P4-8

Croyden Olive Groves – Croyden/Faure, Cape Town
Category Roads: all public roads, from minor suburban roads to major highways.

C.E.L. Paving’s brown pebble exposed aggregate concrete pavers were used on this estate as the landscape architect wanted to build a country road that was durable and would complement the architecture of future houses on the estate.

In addition, natural cobblestones were used to demarcate crossings and borders and to alert road users of oncoming traffic. The pavers, which had been used successfully on a neighbouring estate, were chosen for consistency of finish as well as durability. The colour consistency of the pebbles was painstakingly achieved by sorting through various batches of aggregate.

Professional Team
Architect:  Planning Partners
Engineer:  Ninham Shand-Alex Versfeld
Contractor:  Burger and Wallace Construction
Manufacturer:  C.E.L. Paving Products

Product information
Vintage thick exposed aggregate pavers (Brown) 190 x 125 x 70mm  (±22 000m²)
Wet Cast Cobbles

Judges’ Comments
Superb attention to detail creates an immediate impression of quality. A high-end product which blends in well with its environment.

SUSPENDED CONCRETE FLOOR SLABS
S1-6

Caption S1-6

Milkwood Phase 1 – Aston Bay, Eastern Cape
Category – Residential: houses, flats and townhouses.

A total of 7 235m² of the Econodeck 600 beam and block suspended flooring system was used to create four floors above a basement.  A height restriction and spans up to 10m long posed some engineering challenges. Top reinforcement and mesh were placed over the supporting walls to create a long and continuous slab and this in turn facilitated a reduction in slab thickness.

The use of steel successfully eliminated any deflection problem and created more head room, while the pre-tensioned, high-strength concrete of the ribs ensured long-term corrosion resistance at this highly exposed site.

Professional Team
Architect:  Heinrich Mulder and Associates; M&M Designs
Engineer:  Endecon
Quantity Surveyor: Rousseau Probert Elliott
Contractor:   NJO du Plessis
Manufacturer:   Neat Contech

Product Information
Econodek 600 Plank and Block.

Judges’ Comments
The longer span was cost-effective and the project was innovative.

Ends

DATE  :               September, 2008
ISSUED BY :      David Beer Communication Consultants
FOR  :                 Concrete Manufacturers Association
ENQUIRIES :     John Cairns (011) 805-6742
                           David Beer (011) 888-9467 or 082-880-6726. Email bigsky@ibi.co.za