Effect of bentonite on the strength of fired lateritic soil blocks

Lateritic soils derived from migmatite and charnockite were subjected to stabilization using bentonite as an ideal clay. Moulded blocks were fired at 800 degrees C for strength improvement. It was observed that migmatite-derived lateritic soils respond better to stabilization as the average unconfined compressive strength peaked at 8244 kPa compared to charnockite-derived ones of 2936 kPa strength, both with 6% additive. The differing results are attributed to thermal sintering and pivotal positioning of iron concretions in the respective soils. Plastering may not be required for protection as the water absorption has been reduced to almost zero by the thermal binding effect on the soil grains. Aesthetically, the soils yield attractive reddish brown and deep brown colourations respectively on firing. Copyright (C) 1996 Elsevier Science Ltd.