The Study On Crack Resistance Of Prestressed And Non-prestressed Crumb Rubber Concrete Short Beams

Crumb Rubber Concrete(CRC) is a new type of concrete mixed with rubber crumbs.CRC shows the characteristics of low Young's Modulus, large deformation, high energy dissipation and great crack resistance, because mixing with rubber.The paper studies the mix proportion of CRC which has the equal compressive strength as normal concrete, contrasts the tensile strength and elastic modulus of equal strength CRC and normal concrete. With the rubber content of 150kg/m~3 or less,the tensile strength of CRC is basicly equal to the normal concrete,and the elastic modulus can reach 3.9%～16.6% of the normal concrete.In this paper, the anti-crack performance of the CRC under static load is studied based on the bend test results of 8 CRC short beams and 18 prestressed and unpresressed CRC beams.Based on the results of the test, this paper makes use of the concrete mechanics analysis method to develop a new cracking moment formula of Crumb Rubber Concrete according to the calculation theory of normal section bearing capacity. The conclusion showed the results calculated by the formula fit well with the data of experiment.This paper studies the performance of the superposed beam under the bending moment employing linear analysis methods with the finite element analysis software ANSYS, and compared the results with that of the single-material beam. The conclusion demonstrates that, if the bottom portion of the superposed beam that is composed of the material with low elasticity coefficient and high tensile strain limit, the beam has better performance of anti-cracking.