Effect of gum Arabic content on maximum dry density and optimum moisture content of laterite soil

Abstract

Soil is a material that has been used in construction for centuries and nowadays represents one third of the world's construction. Cement and lime which are common stabilisers used to make soil-based blocks durable have been found to be harmful to the environment. Therefore, finding environmentally friendly materials as a substitute for cement and lime is of vital importance. In Africa, gum Arabic is a widely available organic material (a biopolymer). The objective of this study was therefore to evaluate the effects of gum Arabic on maximum dry density and optimum moisture content of laterite soil in order to use gum Arabic as a binder for the stabilization of laterite soil blocks. Light compaction test (Standard Proctor Test) was carried out for the mixture of laterite soil, sand, and gum Arabic. The proportion of sand was 20% by mass of laterite soil in this mixture; the gum Arabic was varied from 0 to 10% with a step of 2, by mass of laterite soil. The results showed that the maximum dry density decreased from 1883 kg/m3 to 1693 kg/m3 after the addition of 0%–10% gum Arabic in laterite soil, respectively. Whereas the optimum moisture content increased from 14.88% to 18.38% after the addition of 0%–10% gum Arabic, respectively. The observed results of the maximum dry density have been found to be within the recommended range. Based on the findings from this study, gum Arabic can be recommended as binder in the stabilisation of laterite blocks.