The effect of wood ash and sawdust admixtures on the engineering properties of a burnt laterite-clay brick

Abstract

The effects of the addition of sawdust (for burning out) and wood ash admixtures to a 70:30 parts by weight laterite-clay mix were investigated. The admixtures were added in various combinations of proportions by volume (from 0 to 10%). It was discovered that the major contribution of the sawdust admixture is the reduction in the dry density of the finished burnt brick product (from 1755 kg m-3 for the control mix without admixtures to 1512 kg m-3 for mix with 10% sawdust content). The wood ash admixture in line with its pozzolanic nature, was able to contribute in attaining denser products with higher compressive strengths, higher softening coefficients, lower water absorption rates, lower saturation coefficients and lower abrasion indexes. Increasing contents of sawdust in the mixes produced the opposite results in the finished products, mainly due to its effect of producing a less compact structure in the finished product. © 2008 Asian Network for Scientific Information.