Experimental Study On Mechanical And Durability Properties Of Hydraulic Powdered Rubber Concrete

Waste rubber is a solid industrial waste, the quantity of discarded tires increases quickly with the rapid development of automobile industry, and it has become a new source of pollution. If the discarded tires powder is mixed into concrete, it cannot only reduce solid waste, but can improve some properties of concrete. Therefore, it is greatly significant to study powered rubber concrete.This study used tire rubber powder as a concrete admixture. Various percentages of tire rubber powder, by weight of cement, were added into concrete and no cement and aggregate were replaced, on basis of this, concrete mechanical properties were studied. According to characteristics of hydraulic concrete, the durability, for example, permeability, abrasion resistance and freezing-thawing resistance were studied.In this study, 8 mesh, 14 mesh, 16 mesh and 28 mesh powered rubber were chosen .Various percentages of rubber, 3%,6%,9%,12%,15%,by weight of cement ,were mixed into concrete. The total experiment can be divided into three phases. In the first phase, the influence of powered rubber on mechanical properties of cement motor was researched. In the second phase, the influence of particle size and content of rubber on workability of fresh concrete was researched. Slump, density, air content and setting time were all tested. At the same time, compressive strength, tensile strength , splitting elastic modulus of hardened concrete were also tested .In the third phase , the influence of particle size and content of rubber on durability, such as permeability, abrasion resistance and freezing-thawing resistance, was researched. Based on the analysis of test data, the reasons that powered rubber affects concrete properties was discussed. The relationship between the properties of concrete and content and particle size of powered rubber was got. Tests show that powered rubber increases air content and so has the capacity of entraining air into concrete, but has little effect on slump, density, and setting time. Powered rubber reduces mechanical properties of concrete such as flexural strength, compressive strength and elastic modulus, but strengthens deformability. Powered rubber concrete has good freezing-thawing resistance. The test results indicate that powdered rubber has little effect on relative dynamic elastic modulus, but can significantly improve surface antifreeze capacity of concrete. Powdered rubber concrete has better abrasion resistance than not only ordinary concrete but also silica fume concrete.