Research On Seismic Performance Of Tailing Recycled Aggregate Concrete Filled Double Steel Plate Composite Shear Wall

Tailing Recycled Aggregate Concrete Filled Double Steel Plates Composite Shear Wall(TRAC-CSW)combines green building material tailing recycled aggregate concrete(TRAC)with the double steel plates composite shear wall structure.TRAC-CSW has multiple outstanding advantages such as superior seismic performance,high assembly efficiency,high recycling rate,and saving steel consumption.This paper systematically studied the seismic performance of the TRAC-CSW through mechanical tests,finite element simulation,parametric analysis,and theoretical research.The main contents are as follows.(1)Considering the high water absorption rate of recycled coarse aggregate(RCA),the mix proportion of the TRAC was compensated by adding additional water.Six sets of TRAC test blocks were made based on the two parameters of RCA replacement ratio and water-binder ratio.After curing under standard conditions,the mechanical test of TRAC was carried out.The test results presented that with the decrease of the RCA replacement ratio,the mechanical properties of concrete are enhanced.When the waterbinder ratio is lower,the compressive strength and elastic modulus of TRAC are higher,but the increase rate is smaller.The calculation formula of elastic modulus in "Code for the design of concrete structures"(GB 50010)was adjusted by the parameter RCA replacement ratio γ to be suitable for calculating TRAC.Based on the concrete constitutive equation given in the CEB-FIP European standard,the influence coefficient of the constitutive equation is adjusted through the test data,and the constitutive equation suitable for TRAC is obtained.It provides a theory for calculating the peak strain of TRAC in the finite element model(FEM).(2)Six TRAC-CSW specimens were fabricated,which are the same size as the actual engineering.The quasi-static experiment was carried out on the specimens under repeated low-cycle loads.The concrete adopts C40 TRAC and the RCA replacement ratio is 100%.The research parameters are whether to set shear studs,aspect ratio,rib width,axial compression ratio,wall thickness,etc.The influence of different parameters on the loaddisplacement curve,stiffness,ductility,and energy dissipation capacity of the TRAC-CSW was explored.The failure mode was also obtained.The test results presented that the TRAC-CSW has good seismic performance,strong bearing capacity,stiffness,and energy dissipation capacity.(3)Combined with the constitutive model of TRAC and the damage evolution of the steel,the finite element software ABAQUS was used to simulate the TRAC-CSW.Through the hysteretic analysis of the FEM,the stress mechanism and failure mode of the shear wall were explored.The seismic performance indicators such as the load-displacement curve,bearing capacity,stiffness,ductility,and energy dissipation capacity were obtained.The reliability and accuracy of the numerical model were verified by comparing the numerical analysis results with the experimental results.The parametric analysis of axial compression ratio,concrete strength,rib width,steel strength,and aspect ratio was carried out to obtain the influence law on the wall.The parametric analysis guides bearing capacity calculation methods.(4)Based on the test results and parametric analysis,the section characteristics of TRAC-CSW were considered.The calculation method of the normal section flexural bearing capacity was obtained.The deviation between the calculation results and the experimental data is between-14%and 7%.Besides,the average deviation is-6%.The experimental results are in good agreement with the calculated results.The calculated results are conservative,which conforms to the design principle of preserving safety reserves.Based on the factory production process and test results,the seismic design suggestions for the TRAC-CSW were proposed.