Effect of modified clay treated crumb rubber and silica fume on the properties of concrete

The stacking of worn out tyres on the environment is the major concern in the world due its non-biodegradable nature. Environmental issues related with disposal of rubber and also the mining of river sand could be minimized by using crumb rubber as fine aggregate. The objective of the article is to strengthen the interfacial bonding of crumb rubber with cement paste using modified clay for counteracting the strength reduction of rubberized concrete. The microstructure of rubber was examined to study the effectiveness of modified clay treatment of rubber using scanning electron microscopy (SEM). The cement was partially replaced with silica fume (0%, 5%, 10%, 15%, and 20%) and GGBS (30%). The properties of concrete such as workability, unit weight, compressive strength, split tensile strength, flexural strength, and impact strength were studied. The results showed that the inclusion of modified clay treated rubber with silica fume exhibited a low strength reduction of 0.45% compared with control mix which makes the rubberized concrete suitable for the structural elements.