Investigation of Properties of Concrete Using Sawdust as Partial Replacement for Sand

Abstract

The concrete mix ratio of 1:2:4. was prepared using water/cement of 0.65 with  0%, 25%, 50%, 75% and 100% sawdust as partial replacement for fine sand. The coefficient of uniformity   and coefficient of curvature of the sand used in this study was 1.049 and 1.324 respectively which shows that the sand is a well graded sand as it does not exceed  the range of  1 and 3 for ; and  maximum of 6 for specified by the British standard. The aggregate crushing value (ACV) obtained is 43.75 which is within the specified value of 45 as specified by the British standard (BS 812-110 1992). However, values of 40mm, 9mm and 5mm respectively was obtained for workability at 0%, 25% and 50% addition of sawdust as partial replacement for sand, while 14.15 N/mm², 12.96 N/mm² and 11.93 N/mm², were obtained for compressive strength with 25%, 75% and 100% sawdust as partial replacement. The Compressive strength values obtained were found not to conform to the minimum requirement of 17N/mm² for light weight concrete. Using sawdust in a proportion greater than 25% replacement of sand is however detrimental to strength and density properties of concrete.

Keywords: Sawdust, Concrete, Workability, Aggregate Crushing value, Compressive strength,