Suitability of Lateritic Soils as Construction Material in Sustainable Housing Development in Africa : a Geological Perspective

Abstract

Lateritic soils which have been described as highly weathered tropical or sub-tropical residual soils with varying proportions of particle sizes ranging from clay size to gravel, were studied in an attempt to establish its suitability or otherwise as sustainable material in building bricks and housing developments that will meet the present challenge of sustaining the environment without costing too much and maintaining a high standard of strength, durability and aesthetics. Index properties of the lateritic soils tested revealed them as mostly well-graded, comprising both cohesive (silt and clay) and cohesionless (sand and gravel) soil fraction. The mineralogical analysis shows the presence of sesquioxides in the clay portion which were found to be very useful in the natural binding process as well as in the presence of a stabiliser (cement). The geotechnical analysis on the lateritic soil revealed a strong compressive strength with a relatively sound dry density which could guarantee a good durability in resulting bricks made from these soil materials. Further test on the strength and durability of compressed earth bricks (CEBs) made from these lateritic soils revealed a brick with compressive strength ranging between 6.33 and 15.57 MPa which are considered to be of very good strength coupled with its sound durability strength established over a period more than one year under different kinds of severe weather and seasonal conditions. In conclusion, sesquioxides presence and mineralogy of lateritic soils were found to be largely responsible for their good compressive and durability strength which made them good and sustainable materials for CEBs.