Experimental study on performance of rubber particle and steel fiber composite toughening concrete

In this paper the effects of steel fiber and rubber particles on the mechanical properties, flexural behavior, compression behavior and seismic behavior of high strength concrete are studied. The results show that the compressive strength of concrete flexural strength, the elastic modulus of concrete with 5% rubber particles all decreased. After adding 0.9% steel fibers the compressive strength and elastic modulus increased slightly, but the flexural strength increased significantly. Rubber particles have an slight effect on the flexural toughness of concrete. While after adding 0.9% steel fiber the flexural toughness of concrete improve significantly, the failure mode changed from brittle fracture to ductile fracture with multiple cracking phenomenon and the descending segment of load-deflection curve becomes less steep. Rubber particles and steel fibers all can improve concrete compressive toughness obviously, increased the ductility and deformation capacity. After adding steel fibers and rubber particles, because the compressive strength of concrete reduced, the bearing capacity of seismic columns decreased slightly but the hysteresis loop changed fuller significantly, the ductility and energy dissipation capacity enhanced significantly and stiffness degradation become slower.