Zambia – Cutting building costs

The University of Zambia’s Technology Development and Advisory Unit (TDAU) has developed a technology that could reduce the cost of making building blocks by at least 50 per cent. Known as the Stabilised soil-cement block technology, it uses specially prepared suitable soil and stabilises it by adding a small amount of cement and water. The block is then compressed by high-compaction presses, delivering a block that is at least as strong as the concrete equivalent.

The new technology is to reduce cement use by 5-10 per cent and eliminates the need for quarry dust, by using suitable soil. Both plain and interlocking blocks can be made, the latter not requiring mortar. Engineers at the unit claim that from one 50kg bag of cement, 76 interlocking or 100 plain blocks can be manufactured.

When used in the field, eg to build a house, savings between 35-65 per cent can be made, depending on the size of the building and as building material prices are rising, this could prove a particularly attractive advantage.