Influence of waste rubber utilization on the fracture and steel-concrete bond strength properties of concrete

Mechanical and fracture properties of concretes in which the natural aggregate was replaced with two types, crumb rubber and/or tire chips, of waste scrap tire rubber were experimentally investigated. The concrete mixtures were produced at a constant water-to-cement ratio of 0.40 and with a cement content of 450 kg/m(3). A total of 19 concrete mixtures were designed by replacing the fine and coarse aggregates with crumb rubber and tire chips, respectively, at designated replacement levels of 0%, 5%, 10%, 15%, 20%, 25% and 30% by total aggregate volume. The concrete samples were tested for compressive and splitting tensile strengths, modulus of elasticity, fracture ene'rgy, characteristic length, and steel-concrete bond strength. Test results indicated that utilization of rubber significantly affected the mechanical and fracture properties of concretes. Compressive strength and modulus of elasticity of the concretes decreased while the ductility increased as the rubber had been used. Besides, the effect of rubber appeared to be more pronounced at higher rubber content and bigger size. (C) 2015 Elsevier Ltd. All rights reserved.