Assessing Compressive Strength of Concrete with Waste Automobile Tire and Palm Kernel shells as Aggregates

All throughout the world, millions of end-of-service life automobile tires and Palm Kernel Shells (PKS) are generated as waste that require proper disposal. The reuse of these wastes in concrete is regarded as a novel approach that has environmental, health and performance related benefits. On this basis, the current study was designed to investigate the coupled effect of using both PKS and tire chips as aggregates in concrete mixes on the compressive strength and other properties of concrete. A total of twenty-one (21) concrete mixes containing different volumes of PKS and tire chips as a partial to full replacement of the conventional crushed granite aggregates were prepared to evaluate their impact on the fresh (i.e. slump) and hardened (i.e. density and compressive strength) properties of the concrete at 7, 14, 21, 28, 56 and 90days of curing. The results showed that there is a systematic decrease in compressive strength, workability and density of concrete with increase in tire (T) and PKS (P) content. However, up to 50% total aggregate replacement (TAR) level, adequate compressive strength can be achieved for structural purposes. At this optimum point, the mix with P75T25 recorded a compressive strength of 13.27 N/mm2 which represents about 44% of the strength of the control mix. Generally, the inclusion of PKS aggregates improves compressive strength and decrease the rate of strength reduction.