Properties of high strength concrete containing scrap tire rubber

Disposal of waste tire rubber has become a major environmental issue in all parts of the world representing a very serious threat to the ecology. One of the possible solutions for the use of scrap tire rubber is to incorporate it into concrete, to replace some of the natural aggregate. This paper presents the results of an experimental research to analyse the suitability of scrap tire rubber as a partial substitute for natural fine aggregate in high strength cement concrete. Crumb rubber replaced natural fine aggregate from 0% to 20% in multiples of 2.5%. Tests were performed to determine the compressive strength, flexural tensile strength, pull-off strength, abrasion resistance, water absorption and water penetration of these concrete samples and their microstructures were observed using Scanning Electron Microscopy (SEM). It was observed that the compressive strength, flexural tensile strength, pull-off strength and depth of water penetration of the rubberized concrete were less than that of the control mix, while the abrasion resistance and water absorption (up to 10% substitution) exhibited better results than that of the control mix concrete. Rubberized concrete may be used in structures where there are chances of brittle failure. Crumb rubber may be utilized in high strength concrete as a partial substitute for fine aggregate up to 12.5% by weight for obtaining strength above 60 MPa.