Rapid development of the automobile industry has brought the disposal problem of waste rubber tires. Mixing waste rubber tires into concrete can not only solve environmental problems but also improve the mechanical properties of concrete. Rubber aging is one of the main factors to affect the mechanical properties of rubberized concrete. Therefore, an FEM model of rubberized concrete in mesoscale is established in this paper. The influence of rubber aging on the uniaxial compression damage of rubberized concrete is u;studied. The results show that (1) the elastic modulus and compressive strength of rubberized concrete are negatively correlated with the aging level and content of rubber and positively correlated with the particle size of rubber. (2) After uniaxial compression of concrete enters the softening section, the crack resistance of concrete is positively correlated with the aging level and content of rubber and negatively correlated with the particle size of rubber. (3) Compared with the elastic modulus, the compressive strength of rubberized concrete is more sensitive to the change of parameters of rubber, that is, the change range of the compressive strength of rubberized concrete is always greater than the change range of its elastic modulus, when the aging level, content, and particle size of rubber change.

Steel fiber reinforced concrete (SFRC) will appear ununiform corrosion under chloride environment, resulting in corrosion-induced crack. However, the mechanism of corrosion-induced crack of ununiform corroded SFRC is not clear. In this paper, the 3D mesoscale numerical model of SFRC structure is established, the generation algorithm of round straight steel fiber is provided, and the corrosion-induced crack are simulated by XFEM, at the end the damage characteristic of ununiform corroded SFRC are studied. The result shows with the increase of rebar corrosion area, the number of corrosion-induced cracks increase gradually. The width of each corrosion-induced crack decreases linearly with the thickness of the protective layer, and the width of the penetrate crack decrease to 0.08 mm~1.2 mm.