Soil Characterization for the Manufacture of Compressed Earth Blocks in Bujumbura, Burundi

Social housing and urbanization policies in Burundi are ongoing, long-term projects, hence the need for large quantities of construction materials. The use of environmentally friendly construction materials such as earth bricks has a promising future. To prevent premature deterioration of civil engineering structures, in-depth studies of materials prior to their use are essential. It is within this framework that this study was initiated. It aims to determine the physical and mechanical properties of soils at potential sites for the manufacture of compressed earth blocks in Bujumbura, a region located in western Burundi. The samples taken underwent a complete geotechnical characterization, including grain size analysis by sieving and sedimentometry, consistency limits, and modified Proctor tests. The GTR classification (Technical Guide for the Construction of Embankments and Subgrades) identifies them as clayey sands (A1), materials that are acceptable for the manufacture of BTCs, either in their natural state or with the addition of clean sand to remove clay if necessary. The plasticity indices (PI) of 10.1% and 8.5%, liquidity limits WL of 34% and 33%, and Proctor optimums observed for maximum dry densities of 1.99 t/m3 and 1.994 t/m3 for 11.1% and 12% water, are characteristics that qualify them for the manufacture of BTC.