Study On Seismic Performance Of Superimposed Reinforced Concrete Shear Wall Structure With Insulation

A new superimposed reinforced concrete shear wall with insulation(SRCSWI)is proposed in this paper by integrated the insulation panel into the precast exterior concrete panel to achieve the unity of loading and insulation.,.The cast-in-place reinforced concrete and precast intereior concrete panel are main carrying part.,and there only exists a superimposed surface of concrete.In addition,the connection method of the longitudinal reinforcement at the horizontal joints of the SRCSWI is the indirect splicing on one side and the direct splicing on the other side,Compared with the conventional superimposed reinforced concrete shear wall where all longitudinal reinforcements are indirect splicing above the horizontal joints,the over-strength phenomenon in the connection area of longitudinal reinforcements can be reduced to a certain extent,reducing the phenomenon of plastic deformation around horizontal joints.the experimental study and numerical analysis of the seismic performance of SRCSWI structure are carried out in this paper,the main research work of this paper includes the following contents.1.Four full sized specimens were designed to conduct pseudo-static tests,including one cast-in-place reinforced concrete shear wall(CRCSW)specimen,Two full-scale SRCSWI specimens and one full-scale superimposed reinforced concrete shear wall without insulation(SRCSW)specimen.Test results showed that the failure process and mode of the SRCSWI specimens are similar to CRCSW specimen,firstly,The cracks occurred at the horizontal joints,and then the flexural cracks and bending-shear cracks develop upwards gradually,after that the tensile reinforcement which is at the bottom of the wall yields,and the concrete in the compression zone is crushed and destroyed;for the SRCSWI with smaller size and reinforcement ratio of the boundary elements,fewer cracks occurred in the wall,while the opening width of the horizontal joint is relatively larger,indicating that plastic deformation of this specimen focused near the horizontal joints;For the SRCSWI specimens,the cracks along the thickness of shear wall are start from the interior concrete panel to the border between insulation and exterior concrete panel,at the end of the test,there is no crack on the exterior concrete panels,the exterior concrete panels hardly provided any contribution to the stiffness and capacity of the walls;for SRCSWI specimens,SRCSW specimen and CRCSW specimen with the same design axial load ratio,the stiffness,ductility and bearing capacity are comparative,while for SRCSWI specimen with smaller axial force,the bearing capacity is smaller but the ductility ratio and energy dissipating coefficient are larger than the other specimens,the ultimate displacement Angle of all specimens is greater than 1/120 of the limit value of the inter-layer displacement Angle of shear wall structures under the action of large earthquakes as stipulated in China,the specimens owe good deformation capacity;Based on the bearing capacity calculation formula of Technical specification for concrete structures of tall building(JGJ3-2010),the bearing capacity of all specimens was calculated,and the theoretical calculation results were compared with the experimental results,the correctness of the formula is verified.2.Based on the test,the solid finite element model of four specimens was established by ABAQUS software,and the accuracy of the finite element model was verified by the test results;Finally,the parameter analysis is carried out on the basis of the verified finite element model,The effects of the axial load ratio,longitudinal reinforcement ratio in the boundary element and concrete strength on the seismic performance of the SRCSWI were studied.The results show that the ultimate bearing capacity of SRCSWI increases with the increase of axial load ratio,longitudinal reinforcement ratio in the boundary element and concrete strength.