Abstract
Utilizing waste rubber tires in concrete as a partial replacement of aggregate reduces its carbon footprint and modifies its performance. Several researchers have evaluated the properties of crumb rubber concrete (CRC). This article evaluated the potential of one of the most promising testing techniques for concrete (i.e., the stiffness damage test (SDT)) for CRC. Fine crumb rubber aggregate (FCRA) was added as a replacement for fine aggregate at a dosage of 10 % by volume. Results reveal that compressive strength decreased by 29.5 %, 28.4 %, and 28.0 %, and tensile strength decreased by 31.1 %, 31.3 %, and 28.0 % because of FCRA at 28, 56, and 90 days, respectively. A strong relation was found between the strength and time (i.e., specimen age) and was represented linearly with R2 around 0.99 for compressive and tensile strength. The modulus of elasticity of CRC showed 27.7 %, 26.0 %, and 25.5 % reductions at 28, 56, and 90 days, respectively. Poisson's ratio for the same mixture exhibited an increase of about 34.7 %, 31.3 %, and 28.0 % at 28, 56, and 90 days, respectively. The results showed that SDT output parameters, including the hysteresis area, stiffness, plasticity deformation, and elasticity, decreased as a function of time and were sensitive enough to quantify the change of CRC mixture properties. In addition, adding FCRA caused an increase in plasticity deformation and elasticity over time.