STABILISED INTERLOCKING RAMMED EARTH BLOCKS: ALTERNATIVES TO CEMENT STABILISATION

Southampton Solent University with the Good Earth Trust promotes projects in Africa that utilise interlocking rammed earth blocks. The earth used is typically a sandy clay or lateritic soil (red murram), stabilised with between 5-7% cement to improve the strength and durability of the blocks. Only a small quantity of water is necessary to compact the material in the ram and to allow for the hydration of the cement. The interlocks between the blocks reduce the need for 10mm mortar joints. Testing with different soils, surface treatments, lime and cement stabilisers were conducted at Southampton Solent University, UK (Browne, 2005). Ongoing tests at Makerere University in Uganda are researching the use of enzymes and polymers in providing innovative low carbon alternatives to cement. This paper introduces the use of this technology and assesses the different stabilising options to produce low carbon earth blocks.