Combination of Rice Husk Ash (RHA) and Sewage Sludge Ash (SSA) as sustainable replacement material for cement in concrete

Abstract

Increase in the demand of conventional construction materials and the need for providing a sustainable growth in the construction field has prompted the designers and developers to opt for ‘alternative materials’ feasible for use in construction. For this objective, the use of industrial waste products and agricultural by products are very constructive. These industrial wastes and agricultural by products such as Rice Husk Ash and Sewage Sludge Ash can be replaced instead of cement because of their pozzolanic behaviour, which otherwise requires large tract of lands for dumping. In the present investigation, Rice Husk Ash has been used as an admixture to cement in concrete and its properties has been studied. An attempt was also done to examine the strength and workability parameters of concrete. Five different replacement levels namely 5%, 10%, 15%, 20% and 25% are selected and studied with respect to the replacement method. The samples had been tested with non-destructive test to compare with normal concrete (OPC). There was an increment in number of concretes at 10% amount replacement SSA and RHA, but the rebound number declined when the amount replacement SSA and RHA are developing more than 10%. In addition, the concrete also showed increasing of compressive strength within the additional curing period, which was 7 days and 28 days. The overall results indicated that the properties and performance of concrete with 10% of combination of Rice Husk Ash (RHA) and Sewage Sludge Ash (SSA) replacement had reached the most optimum values on the measured.