Performance Evaluation of Hollow Concrete Blocks Made with Sawdust Replacement of Sand: Case Study of Adama, Ethiopia

Hollow concrete blocks (HCBs) are substitutes for conventional bricks and stones in building construction. Experimental testing has been performed on the feasibility of producing HCBs from sawdust (SD). Sawdust is substituted with fine aggregate (pumice) by weight proportions 3, 6, and 9%. Sawdust is treated with tap water to remove foreign materials. Different tests were performed on blocks in order to find the effect of sawdust and to confirm whether blocks produced will satisfy the minimum acceptable standards. Different tests were conducted on the samples for 21 days as in Ethiopia to reflect the pratical application. Compressive strength of sawdust with additions of 3, 6, and 9% was 1.17, 0.99, and 0.51 N/mm^2, respectively. Replacement with 9% resulted in a higher rate of water absorption. The density of HCBs was found to be between 633.06 and 638.21 kg/m^3. In light of the results, it is concluded that 3% of sawdust can be optimized for the production of blocks.