Comparative study of the mechanical and thermal performance of two-clay-Based Compressed Earth Blocks (BTC) for housing building

This study is part of a sustainable construction approach by exploring the mechanical and thermal performance of compressed earth blocks (BTC) made from Dialakoro and Kita clays. BTC measuring 23 x 11 x 8 cm and cylindrical specimens measuring 5 cm in diameter by 10 cm in height were manufactured for the mechanical tests, and rectangular specimens measuring 27 x 27 x 3 cm were used for the measurement of thermal conductivity. The water absorption results by capillary action reveal a low resistance to humidity for the BTC from Kita (caused by rapid degradation in the presence of water) with a coefficient of -8 g/cm²·s¹/², compared to 2 g/cm²·s¹/² for those from Dialakoro, indicating better resistance to humidity. In terms of compressive strength, Dialakoro BTC averaged 6,85 MPa on the 28th day compared to 4,97 MPa for Kita. After 7 days, both types of BTC exceed the minimum permissible compressive strength for BTC, which is 2 MPa according to the NF EN 772-1 standard, with 3,86 MPa for Dialakoro and 2,29 MPa for Kita. Thermal conductivity measurements also show an advantage for Dialakoro’s BTC with 0,86 W/m·K compared to 1,02 W/m·K for Kita’s, suggesting better thermal insulation. These results confirm the superior potential of Dialakoro’s BTC in terms of mechanical performance and thermal efficiency.