Study On Compressive And Bending Behaviors Of Crumb Rubber And Steel Fiber Reinforced Recycled Aggregate Concrete

With the development of the society, a large number of waste concrete and waste rubber are produced each year, which brings us a lot of environmental problems. To solve this problem and in order to improve the defects of concrete material itself (lower tensile strength and significant brittleness, etc.), many scholars from all over the world have done a lot of research work. Because steel fiber can enhance the tensile properties and energy dissipation capacity of concrete and inhibit the crack extension, improve the brittleness of concrete, and, on the other hand, crumb rubber can improve the ductility and deformability, a new kind of environmental concrete material is studied in this paper. This material is made on the matrix of recycled concrete mixed with steel fiber and rubber particles, which is named crumb rubber and steel fiber reinforced recycled aggregate concrete(RSRAC).In this paper, the compressive performance at room temperature and bending properties under high temperature of RSRAC were studied, the influence of rubber content on the compressive performance at room temperature and bending properties under high temperatures of RSRAC, and the damage mechanism of RSRAC exposed to elevated temperature and the improve mechanism of rubber particles on the performance of concrete were preliminarily discussed. The main three aspects included in this paper are as follows:(1) Through the compressive test of RSRAC cubes and cylinders at room temperature, the influence of rubber content(0%,4%,8%,12%, and16%) on the failure mode, the stress-strain curve, compressive strength, Young’s modulus and energy dissipation of concrete material were analyzed. The experimental results show that with the increase of rubber content, compressive strength and elastic modulus of RSRAC decline gradually, but the ductility is improved to some extent, which shows best at the rubber dosage of8%.(2) Through the observation of the changes of the appearance of RSRAC specimens after high temperature, the measurement of the quality loss of concrete and the analysis of the failure pattern, the influence of rubber content and high temperature on the appearance of the concrete and the mass loss, the damage mechanism of RSRAC under high temperature and the mechanism of rubber particles relieve burst and high temperature damage were preliminarily discussed.(3) Through the research of the bending performance of trabecular specimens under high temperature(25℃,200℃,400℃,and600℃), the influence of failure mode of RSRAC, load-deflection, bending strength and peak deflection were analyzed. The test results show that the incorporation of rubber particles helps slow down the damage under high temperature and improve the anti-cracking performance of concrete, which shows best at the rubber content of8%-12%.