Evaluation of the properties of lightweight concrete using periwinkle shells as a partial replacement for coarse aggregate
The properties of lightweight concrete, such as aggregate impact value, aggregate crushing value and compressive strength were assessed utilizing periwinkle shell (PWS) as partial replacement for coarse aggregate. Standard mix of 1:2:4 with varying percentages of 0%, 10%, 20%, 30%, 40%, 50% and 100% partial replacement of PWS using water/cement (W/C) ratio of 0.55 was used. Seventy two cubes of 150 mm x 150 mm x 150 mm were casted; allowed to set for 24 hours before remolding, and were properly cured. The strength characteristics of each cube were evaluated using Compressive Testing machine at the curing ages of 7, 14, 21 and 28 days. The ACV and AIV obtained are 31.59% and 22.61% respectively which is within the acceptable limit. An optimum compressive strength value of 16.79 N/mm2 and 16.71 N/mm2 was obtained with the addition 20% and 30% partial replacement of coarse aggregate with PWS in 28 days. These values are within 15-25 N/mm2 and it is suitable for Lightweight concrete. The research demonstrates that the utilization of PWS in structural/insulating lightweight concrete, at lower volume of replacement, will reduce the utilization of granite in concrete. Thus, decreasing the production cost of concrete and the ecological contamination brought about by the dumping of periwinkle shell.
Keywords: Lightweight Concrete, Periwinkle, Aggregate Impact Value, Aggregate Crushing Value, Compressive Strength, Environmental Pollution