Study On Mechanical Performance Of Recycled Aggregate Concrete Compoents Containing Waste Concrete And Bricks

Recycled aggregate made from the demolition of old houses in the last century contains a lot of red bricks.For the reason that there exist obvious differences between the properties of red bricks and waste concrete,the properties of recycled aggregates containing waste concrete and red bricks are different from recycled aggregates containing only waste concrete.The current construction solid waste treatment process cannot efficiently separate brick aggregates.Therefore.how to rationally utilize those of recycled aggregates has become a concern of the industry.From the perspective of engineering application,this thesis aims to provide a reasonable solution for the efficient and rational use of recycled aggregate concrete containing a large amount of red bricks.This paper analyzes the mechanical properties of the recycled aggregate concrete compoents containing waste concrete and bricks through structural loading tests,demonstrates the feasibility of application in actual projects,puts forward suggestions for improvement.The main research contents of this thesis can be summarized as follows:(1)3 beams made with natural aggregate concrete(NAC beam)and 3 columns made with recycled aggregate concrete containing waste concrete and bricks(RAC beam)with strengths of C25,C30,C35 were designed.Bending tests were carried out on six beams to analyze the differences in the process of stress,failure characteristics,deformation ability,ductility and bearing capacity between RAC beams and NAC beams of the same strength.In the process of loading to failure,the RAC beam shows four stress stages similar to the NAC beam,which also accords with the plane section assumption.However,compared with the NAC beam of the same strength,the ultimate bearing capacity of the RAC beam is slightly smaller,the load cracks on the surface of the beams are more likely to generate and develop during the loading process,the stiffness decreases more significantly,the deformation is greater,the deformation from yield to failure is smaller.and the ductility is poor.On the basis of test results,there is no unacceptable difference between the RAC beam and the NAC beam of the same strength.which means it is feasible to apply RAC beams to engineering(2)3 columns made with natural aggregate concrete(NAC column)and 3 columns made with recycled aggregate concrete containing waste concrete and bricks(RAC column)with strengths of C25,C30,C35 were designed.A small eccentric compression performance test was carried out on 6 columns to analyze the differences in the stress process,failure characteristics.deformability and bearing capacity between RAC columns and NAC beams of the same strength In the process of loading to failure,the RAC column shows three stress stages similar to the NAC column,which also accords with the plane section assumption.But compared with the RAC column of the same strength,the deformation of the RAC column is larger.However,the ultimate bearing capacity of RAC column is slightly higher,which may be due to the difference in axial compressive strength.On the basis of test results,there is no unacceptable difference between the RAC column and the NAC column of the same strength,which means it is feasible to apply RAC beams to engineering.(3)Two steel frames embedded with hollow slabs made from recycled aggregate concrete containing waste concrete and bricks(RAC hollow slab)were designed,one of which has a hole and the other has no hole.The pseudo-static test is carried out on the two frames to analyze the hysteresis curve,skeleton curve,loading phenomenon and failure mode of two frames embedded with RAC hollow slabs.The test results indicate the steel frames embedded with RAC hollow slabs have good seismic performance,the loading phenomenon and failure mode of the frames are similar,whereas the wall with a hole will affect the stiffness and bearing capacity of the structure to some extent.The existing installation process and connection method are reliable,but they can still be improved.On the basis of test results,there is no unacceptable phenomenon in the test,which means it is feasible to apply the RAC hollow slab to engineering.