Effect of crumb rubber proportion on compressive and flexural behavior of concrete

The compressive and flexural behavior of crumb rubber concrete (CRC) was investigated with the content of crumb rubber ranging from 5% to 15% by volume. The cubic compressive strength and the stress-strain curve under uniaxial compression were measured and the flexural tensile strain was recorded using a dynamic strain indicator. The results show that the elastic modulus of CRC decreases noticeably, and the peak compressive strain can reach 4106 × 10-6. The tensile strain curve exhibits a significant yield limit of CRC specimen. The ultimate tensile strain of the four-point bending test can reach 260 × 10-6-640 × 10-6. Those measured strain values are much greater than the controlled group, indicating that the ductility and the deformation of concrete can be greatly enhanced with the incorporation of crumb rubber. In addition, the data of cubic compressive strength for one-year age specimens shows CRC is steadily gaining later-strength.