College of Hydraulic Science and Engineering, Yangzhou University
National Natural Science Foundation of China (No. 51809227)、Postgraduate Research &Practice Innovation Program of Jiangsu Province (No. XKYCX19_097)
In order to study the influence of rubber content on the fracture mechanical properties of concrete under cyclic loading, monotonic and cyclic loading fracture tests were carried out on five kinds of notched concrete beams with different rubber content (0, 5%, 10%, 15% and 20%). According to the load - crack mouth opening displacement (P-CMOD) curves obtained by fracture tests, the fracture energy and dissipated energy of rubber concrete are calculated. Combined with the failure modes of typical rubber concrete specimens, the influence of loading conditions and the content of rubber content on the mechanical properties and energy dissipation of concrete is analyzed comprehensively. The results show that with the increase of rubber content, the strength and elastic modulus of rubber concrete decrease gradually, while the fracture energy increases gradually. Under cyclic loading, the continuous and gradual accumulation of concrete dissipated energy with cyclic loading is similar to the accumulation of crack mouth opening displacement,the damage and failure process also presents a "three-stage" characteristic. The total dissipated energy increases with the increase of rubber content, but it does not exceed the fracture energy.