Strength Properties of Hydraulic Cement Concrete Pavement Incorporating Coconut Shell as Coarse Aggregate

Coconut shell being a hard and not easily degradable material if crushed to size of coarse aggregate can be a potential material to replace coarse aggregate in concrete. In this study the characteristics of the coarse aggregate and the coconut shell were evaluated. Properties of fresh and hardened concrete with partial replacement of coarse aggregate with coconut shell were also studied. Concrete specimens with 0%, 5%, 10%, 15% and 20% by weight of coarse aggregate replacement with coconut shell were made at 1:2:4 mix ratio. The compressive strength for all the concrete specimens was evaluated at 7, 14, 21 and 28 days and constant water cement ratio of 0.5 was maintained for all the concrete specimens. The aggregate crushing value of the coarse aggregate and the coconut shell were 23.47% and 28.25% respectively and the aggregate impact value of the coarse aggregate and the coconut shell were 17.44% and 20.2% respectively. The slump values, densities and compressive strength of concrete decreased as the percentage replacement with coconut shell increased. Concrete produced with 0%, 5%, 10%, 15% and 20% replacement attained 28 days compressive strength of 38.17, 35.11, 32.14, 31.18, and 29.14 N/mm2 respectively. The results obtained in this study showed that coconut shell satisfied the requirements for coarse aggregate and can be used as partial replacement of coarse aggregate (up to 20%) in concrete pavement production