An Experimental Investigation for The Performance of Crumb Rubber and Fly Ash Concrete

Document Type : Original Article

Author

Delta Higher institute for Engineering and Technology

Abstract

The utilization of recycled rubber tires as a partial substitution of the natural aggregates in concrete is the solution for safe disposal of it. Since that rubber affects the mechanical characteristics of concrete negatively due to the rubber and cement mortar low cohesion, it was necessary to improve these properties by adding pozzolanic additives such as fly ash. The objective of this paper is to study the effect of treated crumb rubber and fly ash as a partial replacement of sand and cement, respectively on the performance of concrete. The crumb rubber (CR) has been treated with benzene. CR particles were added as a partial substitution of sand by 5%, 10%, 15%, and 20% of its weight, and the cement was replaced with fly ash by 15% of its weight. The slump test was done to assess the consistency of the concrete. The results showed that compressive strength decreased for CR mixes by 7.14%, 18.36%, 26.5%, and 35.7% when compared to the control mix compressive strength and the tensile strength decreased by 6.5%, 10.8%, 18.9%, and 35.13% than that of the control mix at the age of 28 days. With an increasing CR ratio, the modulus of elasticity reduced and the water absorption rate for CR mixes increased compared to the control mix. The mixture containing 5% CR achieved the highest value of compressive, flexural, and indirect tensile strength, and the lowest water absorption rate in comparison to the other mixtures including CR particles.

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