Precast concrete is in the forefront of construction in First World countries such as the United States, the UK, Australia, Canada and throughout Western Europe. It is also gaining ground in developing countries in the Middle East and Eastern Europe.
And here in South Africa, too, precast is a name which defines fresh, innovative thinking in the construction world.
From hollow-core precast concrete slabs to concrete beams, columns and building facades, the precast concrete products range is so versatile that conventional in-situ concrete is being edged virtually into a subsidiary role because of its substantially higher labour costs. There is of course a place for both, but architects and builders are finding that the most efficient way to construct precast concrete buildings is to design a hybrid building which is predominantly precast, stitched together with in-situ concrete.
Energy-efficient building with pre-cast concrete slabs
Internationally, precast concrete hollow-core slabs are being employed in all types and all heights of buildings, from double storey to high-rise structures, and in all market sectors – residential, offices, shopping centres, steel structures, industrial applications, multi-storey car parks, casinos, hotels and motels. In fact, hardly any building construction is undertaken today without precast concrete slabs. One notable current theme is in the construction of stadiums and large auditoriums, where extensive use of precast concrete precast products is made, from raked beams to concrete columns, precast concrete hollow core slabs as the base for seating – and even the seats themselves.
The countries mentioned are also in the forefront of developing products that enhance the energy-efficiency of buildings by using sandwich precast concrete wall panels. This is a rigid insulation contained between two precast concrete panels used as a façade and which have the added benefit of very high acoustic and vibration control.
Grain storage facilities, cattle housing, retaining and bunker walls, warehouse firewalls, tanks and security walls – here are still more applications demonstrating the extraordinary versatility of precast concrete hollow-core wall panels.
And precast concrete noise walls are being used along international highways to dampen traffic noise in built-up areas of major towns.
PRECAST CONCRETE SLABS IN SOUTH AFRICA – Reaching higher and breaking with tradition
After nearly 30 years in South Africa, the Echo Group of companies is making major inroads into the precast concrete industry, and at the same time playing a market-leading role in developing the technique’s great potential in fast-tracking the construction of high-density housing and commercial buildings.
Traditionally, precast concrete hollow-core slabs have been used in buildings of up to four floors high, but in recent years Echo has been the first to venture into 5-6 storey load-bearing masonry structures –with huge success and significant cost savings to developers. The Concrete Manufacturers Association (CMA), of which Echo is a member, has published the audited findings of a panel of independent professionals compared the costs of precast concrete versus in-situ concrete in the construction of two large residential complexes in Johannesburg and Pretoria.
To read the startling results of their investigation, go to the CMA website at www.cma.org.za.
Quick, clean and easy
Pre-cast Concrete Slabs in Wall ConstructionIn South Africa, precast concrete hollow-core retaining walls and security walls are hugely popular, and for good reason. Construction is quick, clean, and easy. The high-strength concrete, combined with prestressed strand allows for very high loads to be imposed, delivering walls whose formidable strength cannot be matched by any other product.
Product improvement and refinement is ongoing. Echo has a number of research and development projects under way which will reinforce the company’s long-established leadership position in the South African precast concrete hollow-core slabs market These projects will place Echo South Africa among international leaders in the field.
Finally, a word of encouragement for South African engineers: Precast concrete construction is going to get even more efficient. Echo is working with prominent engineering practices to develop even more user-friendly and environmentally beneficial methods to build precast concrete structures and so advance the capacity and technical know-how of the country’s construction industry.
In-situ cast concrete has had its day, it’s becoming increasingly uneconomical, and precast concrete’s time has come to replace it as the preferred method of concrete construction.