Influence Of Repeated Use Of Coarse Aggregate On Mechanical Properties Of Recycled Concrete

In this paper,according to the source of recycled aggregate and production technology in China,On the basis of further study on the characteristics of recycled coarse aggregate,the influence of recycled coarse aggregate concrete on the mechanical properties of concrete is discussed,from the mechanical properties to talk the possibility of recycled use about recycled coarse aggregate concrete.Test results show that with the increasing of recycling times of R1,R2 and R3 recycled coarse aggregate,recycled coarse aggregate apparent density decreases gradually,rate of water absorption increases gradually,especially R3 coarse aggregate contains independent mortar block content,water absorption rate,crushing index are more increasing than R1 significantly.With recycling times of recycled concrete increase,strength level and replacement rate are the same,slump of recycled coarse aggregate concrete decreases,with times increases,slump loss of recycled concrete increasesWith recycled coarse aggregate first,second and third recycled number increase gradually,the same replacement rate of recycled coarse aggregate compressive strength decrease gradually,when recycled coarse aggregate third recycling and replacement rate is 100%,and the first times,recycled coarse aggregate replacement rate is 100%,compared with ordinary concrete,the strength reduction is obvious.With increasing of number of recycling and the same strength grade,coarse aggregate concrete elastic modulus decreases more significantly.C20,C30 the same strength grade?the comparison of the semi precast internal casting coarse aggregate concrete short column and integral pouring reinforced concrete short column specimens(C20-NN C30-NN)the result show that the overall failure process of the both is close to,and in the process of the experiment test,the pouring of recycled coarse aggregate concrete appear loosening,overall good integrity,when the component is vertical load,pouring semi precast internal regeneration of coarse aggregate concrete application is feasible.