Basic Mechanics Performance Study Of Rubber Modified Recycled Concrete After High Temperature

In this paper, based on the mechanism of concrete spalling, the basic mechanical properties and spalling resistance of recycled concrete were comprehensively considered. 141 recycled concrete specimens were made to explore the basic properties of recycled concrete and rubber modified recycled concrete before and after high temperature.Under normal temperature and after experimental study on basic mechanical properties of 200℃and 400℃,600℃high temperature found:after high temperature, recycled concrete relative residual strength. With the increase of temperature and lower; after high temperature should be stress-strain curves tend to be flat, elastic modulus, axial compressive strength, peak stress, increased with temperature and decreased.The experimental investigation of recycled concrete specimens on the mechanic performance at normal、200℃、400℃ and 600℃ indicates that the relative residual strength of recycled concrete decrease with the rise of temperature after high temperature process. Through the uniaxial compression tests on the rubber modified recycled concrete specimens under normal temperature, the results show that the ductility of the rubber modified recycled concrete specimens is better with the increase of the rubber powder content.Through the modification of rubber regeneration concrete specimen of high temperature test, and uniaxial compression tests on specimens after high temperature results show that after high temperature, the same rubber content of rubber modified of recycled concrete specimen, with the increase of temperature, lower elastic modulus, peak stress decreases, the limit strain increases, should stress-strain curves tend to be flat. The deformation properties of the rubber modified recycled concrete specimens with 4%,9% and 0 were found by comparing with the high temperature mixing ratio of 4%.Through of recycled concrete test piece and rubber modified recycled concrete specimens. After high temperature mass loss and changes in the appearance of the contrast analysis found that the rubber powder modified of recycled concrete after high temperature were not burst, and rubber powder modified of recycled concrete cube specimens in, a plurality of test pieces burst appears. It shows that rubber powder can improve the burst performance of recycled concrete at high temperature.