Effect of rice husk ash on mechanical properties of concrete containing crushed seashell as fine aggregate

Abstract

This study reveals how mechanical properties of concrete containing crushed seashell is influenced by use of rice husk ash (RHA). This experimental program comprises of twelve concrete mixes. All the concrete mixes were created by substituting 0, 10%, 20%, and 30% of fine aggregate with crushed seashells and by substituting 0, 10%, and 20% of cement with RHA. The M30 grade mix design was chosen for the study. Tests were carried out on fresh samples of different concrete mixes to find out slump and other properties. Tests also were conducted on hardened samples to ascertain their split tensile, compressive and flexural strength after 7 days, 28 days and 90 days of curing under water. The experimental observations indicate that use of RHA based concrete mixes improves the strength in comparison with that of crushed seashell based concrete mixes. In seashell based concrete, the strength gradually decreases at all percentage of replacement of crushed seashells with fine aggregate. Further, it is observed that, partial substitution of cement with RHA increases strength in all the concrete mixes. The result indicates higher compressive, split-tensile and flexural strength at 10% partial replacement of fine aggregate with crushed seashells and 20% partial substitution of cement with RHA.