Influence of Coconut Fibers on the Physical and Mechanical Properties of Stabilised Compressed Earth Blocks

The present research aims to determine the influence of coconut fibers from coconut palms on the physical and mechanical properties of compressed and cement-stabilized earth blocks. The study focused on the density, capillary absorption, compressive strength and flexural strength of the blocks. The first part of this study is devoted to the determination of the characteristics of the soil and those of coconut fibres. Five fiber contents (0, 0.1, 0.2, 0.3 and 0.4%) were used and the soil consists of 70% sand and 30% clay silt. Three cement contents were incorporated (2%; 4% and 8%). Two types of specimens are then manufactured by mixing the fibres with the earth-cement matrix: 14x9.5x29.5 cm3 blocks for compression and 4x4x16 cm3 briquettes for bending. The latter are stored away from the sun until maturity. From his studies, it appears that the density of the blocks decreases with increasing fiber content and the opposite is observed with capillary absorption. Overall, the compressive strength decreases with increasing fiber content and increases with cement content. However, the flexural strength increases with the fiber content but within a certain limit: beyond 0.3% fiber, the strength drops. Keywords: Clay soil – Coconut fibres – Cement – Tensile strength – Compressive strength