橡胶集料掺量对混凝土压弯性能的影响

Effect of Crumb Rubber Proportion on Compressive and Flexural Behavior of Concrete

针对橡胶集料混凝土的抗压及抗弯性能,在50%-150%橡胶集料体积掺量下进行立方体抗压强度以及单轴受压应力-应变全曲线试验,并利用动态应变仪测量了4点弯曲状态下的拉应变.试验结果表明,橡胶集料混凝土的弹性模量较基准混凝土有大幅度的降低,峰值轴压应变可达4106×10^-6,弯曲状态下,拉应变曲线评定结果表明橡胶集料混凝土存在明显的屈服点,极限拉应变可达260×10^-6-640×10^-6.这些测试所得的应变数值都大大超过基准混凝土,表明掺入橡胶集料可有效地提高混凝土的韧性和变形性能.同时,对1年龄期的橡胶集料混凝土试件的立方体抗压测试表明,其后期强度呈现可观的增长.

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 stressstrain curve under uniaxial compression were measured and the flexural tensile strain was recorded using a dy- namic strain indicator. The results show that the elastic modulus of CRC decreases noticeably, and the peak compressive strain can reach 4 106 ×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.