Assessing the Effectiveness of Coconut Shell (CS) as Aggregate in Concrete

High cost of constructional materials coupled with the clamour to reduce environmental stresses due to excessive usage of natural aggregates has demanded research into the use of alternative materials for construction. Coconut shell is one of the most prevalent agricultural solid wastes in several tropical countries. For coconut shell aggregate to be used efficiently for construction purposes, it is imperative to investigate its properties. Therefore, this study examined the effect of coconut shell as fine and coarse aggregate replacement on the behavior of concrete with respect to some vital properties. The coconut shell concrete was designed for characteristic strength of 30MPa with the incorporation of coconut shell as replacement for fine and coarse aggregate at 10 %, 20 % and 30 % of volume fractions respectively. The workability, compressive strength as well as densities and water absorption of 96 cured concrete samples were evaluated at 7, 14, 21 and 28 days and discussed. The results showed that increase in replacement of coconut shell volume fractions yielded increase in workability and water absorption with corresponding decrease in the mechanical properties of the concrete, however 28 day compressive strength of 25 MPa and density of 1874 kg/m3 was obtained for 30 % respective replacement of fine and coarse aggregates.