Strength Properties Assessment of Sesame Straw Ash Blended with Rice Husk Ash as an Alternative for Cement in Concrete

Abstract

This paper aims at assessing the influence of using Sesame straw ash (SSA) blended with rice husk ash (RHA) as an alternative for cement in grade 20 concrete. Setting times, soundness and consistency tests were carried out on SSA-RHA-cement paste, while the slump  (workability) test and strength tests were conducted on concrete. Influences of SS-RHA on concrete and cement paste were examined for the  addition of 0, 5, 10, 15, 20 and 25 % by weight of cement, and 3, 7, 28, 56 and 90 days were considered for the curing period. The result shows that  the addition of SSA-RHA decreases the workability (slump) of fresh concrete, but increases the consistency, soundness and setting times of SSA-RHA- cement paste. Moreover, the splitting tensile strength and compressive strength of SSA-RHA-concrete increase as the curing time increases and  decrease as the quantity of SSA-RHA increases. It was established that at 28 days of curing, the concrete’s strength made with 15 % SSA-RHA was  beyond the design strength of 20 N/mm². In addition, the densities of SSA-RHA-concrete samples fall within the range of 2200 kg/m³ to 2600 kg/m³.  Finally, it was concluded that the maximum quantity of SSA-RHA to be used should not be more than 15 % for the production of concrete.