Social housing projects in Gauteng could be speeded up – and build quality substantially improved – with the introduction of a new foundation system adapting Echo hollow-core prestressed concrete floor slabs, traditionally used in multi-storey commercial and residential buildings.
Long-term tests have shown the ground beam system outperforms traditional foundation systems used in social housing construction.
The Agrément Certificate-approved method – designed for small, single-storey structures – involves embedding separate cut-to-measure ‘slices’ of an Echo prestressed slab in the ground across the width of the house. The exposed raised edges of the concrete beams become the firm foundation on which further precast slabs can then be laid to form the floor.
The system is officially known as the CMA Building Foundation Beam – the CMA, the Concrete Manufacturers Association, being the Agrément certificate holder – and Echo Prestress holds manufacturing licence rights for Gauteng. It is designed to support single-storey structures of a maximum size of 6.6 by 6.2m and strict quality manufacturing and installation conditions have been imposed by the SA Agrément Board.
“Like all great ideas, it’s simple,” says Echo Prestress marketing director Melinda Louw. “And it is a much faster way to build sound foundations for social housing. Indeed, it has been developed specifically for this purpose.”
Trials using the system were initially carried out in the Free State and for several years people have been living in homes there with ground beam foundations installed by Bloemfontein-based slab manufacturer Stabilan, a CMA member company.
“The houses are looking good,” says Louw. “No cracks have developed – in strong contrast to surrounding homes which, built on traditional rafts, are cracking badly.”
Using its pioneering technology refined over 25 years in the hollow-core concrete slab business, the Echo Group has already made a significant contribution to some of the country’s most successful affordable housing projects, including multi-storey high-density apartment buildings.
“Now, with the ground beam concept, Echo is geared to bring its expertise to bear in support of government initiatives to push forward the construction of single-storey social housing,” says Louw.