Effect of Sisal Fibre on Partially Replaced Cement with Periwinkles Shell Ash (PSA) Concrete

An investigation on the effect of sisal fiber on partially replaced cement with Periwinkle Shell Ash in Concrete was carried out. Sisal fiber of 40mm length which forms 1% of the mix by weight with Periwinkle shell Ash as a partial replacement for cement was used to cast the concrete. Compressive strength test was carried out using 0%, 5%, 10%, 15%, 20%, 25% and 30% of Periwinkle Shell Ash as partial replacements of cement at different curing ages of 7, 14, 21 and 28 days. A skewed result was observed showing a significant increase in the compressive strength recorded in 21 and 28 days of curing whose peaks are at 5% replacement of PSA in the fiber-reinforced- concrete after which, there was a continuous decline in compressive strength of concrete as the percentage of PSA increased. The peak compressive strength value of 28.8 N/mm^2 was obtained at 40mm sisal fiber and at 28 days curing age. This is followed by a compressive strength value of 26.15 N/mm^2 after 21days of curing, all gotten at 5% PSA replacement. This makes 5% the optimal and apparently an exclusive PSA content for Sisal fiber-reinforced-concrete.