Research On The Uniaxial Compression Performance And Damage Model Of Recycled Concrete

With the shortage of land resources and gravel resources,as a kind of environmentfriendly building materials,recycled aggregate concrete has become one of the hot research subject for the domestic and foreign scholars in gradually,and has obtained fruitful research results which has practical significance.Meanwhile, Conclusions made by different researchers are usually not very consistent for the differences in RCA from various sources,even opposite.Previous research results show that the failure process have no essential distinction between recycled aggregate concrete and normal concrete.Similarly, damage theory is suitable to describe the failure process of recycled aggregate concrete,there is no reasonable damage model can describe the compressive performance for recycled aggregate concrete.In this paper,two kinds of strength grade waste concrete which used in building structure commonly, C30 and C40,was crushed into recycled aggregate respectively.Five substitution rate was considered in each of the recycled coarse aggregate(0%、30%、50%、70%、100%),the cube compressive strength test and uniaxial compressive test were carried out.Based on the above experimental results,analysing the effects made by recycled coarse aggregate(RCA)from different sources in cube compressive strength 、 elastic modulus 、 peak strain and ultimate strain for the recycled aggregate concrete.Based on the experimental data of uniaxial compressive test for recycled aggregate concrete,regarding it as conmon concrete with initial damage, apply the initial damage to quantify the different sources and substitution rate of RCA.The ideal stress-strain curve under uniaxial compressive test was taken as the reference curve,a one-dimensional compression damage model which can describe the uniaxial compressive behavior of the recycled aggregate concrete is established,and validated.Try to analysis the damage evolution process with different recycled coarse aggregate substitution rate and different sources under uniaxial compression,a lot of regular conclusions are obtained in this article.According to the one-dimensional compression damage model established in this article,the capacity of beam for recycled aggregate concrete is researched and calculated based on programs in MATLAB,it is instructive in the design of the recycled aggregateconcrete member.