Production of composite bricks from sawdust using Portland cement as a binder

Abstract

A study was conducted between October 2004 and April 2005 in Kampala District, with the objective of investigating the feasibility of making sawdust-cement composites using saw dust. A total of 48 bricks were made in the Faculty of Forestry and Nature Conservation laboratory based on volume ratios of sawdust to cement (3:2 and 2:1). Mass was measured using a weighing balance and density calculated from mass and volume of the bricks. The composites were tested for compressive strength using a universal testing machine, as they cracked due to compression. The mean compressive strength values were 1.61 N mm-2 and 1.986 N mm-2 for 50 x 50 x 50 mm composites with sawdust to cement ratios of 3:2 and 2:1 respectively; and 1.778 N mm-2 and 2.21N mm-2 for 100x100x100mm composites with sawdust to cement ratios of 3:2 and 2:1 respectively. Analysis of variance (ANOVA) indicated significant differences (P<0.05) in strength values of the two compositions. Soaked composites swelled irrespective of the cement to sawdust ratio. The compressive strength for the soaked bricks was approximately 40% of the dry weight strength. The composite bricks were found to be unfit for paving and medium heavy load wall construction. Due to their light weight, by imparting decorative mosaics they can be used for interior wall paneling and decoration, where minimal wetting is experienced.