| The precast concrete structure meets the requirements of industrial production and it has broad prospects in the field of construction.The precast sandwich-panel shear wall combines the advantages of precast concrete structure and cast-in-place structure,and has the characteristics of good integrity and convenient construction.However,the joints of the superimposed surfaces of the existing sandwich-panel shear walls are unevenly distributed along the wall,with consuming much steel,and have low assembly efficiency.A new type of precast sandwich-panel shear wall is proposed in this paper based on the optimization of the connecting bar form and the connection method of the superimposed surface.The new precast sandwich-panel shear wall uses precast connecting bar to replace the general truss to achieve the connection of the superimposed interface,which simplifies the form of force transmission features and also improves the precast efficiency and manufacturing accuracy of the sandwichpanel shear wall.For studying the mechanical behavior of the new precast sandwich-panel shear wall and verifying its collaborative working ability and seismic behavior under seismic loads.This paper focuses on three new precast sandwich-panel shear wall specimens,a general sandwich-panel shear wall specimen and a cast-in-place shear wall specimen.They were researched by pseudo-static testing and the finite element simulation.Based on test results,the parameters for simulation analysis were carried out.The main work and results in this paper are as follows:(1)The common forms and existing problems of precast sandwich-panel shear walls were concluded and analyzed.To improve the precast efficiency and the force transmission performance,a new type of precast concrete sandwich-panel shear walls is presented—based on the precast connecting bars.(2)Based on experimental studies on three types of shear wall specimens under low-cycle reversed loading test,experimental research and theoretical analysis were conducted on different aspects,and the seismic performance of the new sandwich-panel shear wall was comprehensively evaluated.The results of test show that the characteristics and trends of the new sandwich-panel shear wall are basically consistent with the cast-in-place shear wall and the general sandwich-panel shear wall on stiffness,bearing capacity,hysteresis mode,ductility and other characteristics,Specimens show good integrity throughout the test.(3)Low-cycle reversed loading test on new shear wall specimens were conducted under different axial compression ratios.The results show that the increase in axial compression ratio has a certain positive effect on the improvement of the bearing capacity of the new shear wall specimens.The increase of axial compression ratio greatly delays the cracking of the new shear wall specimen.From the point of view of the limit displacement,the increase of the axial compression ratio is not conducive to the ductility of the shear wall to a certain extent.Therefore,the design and application of the new precast sandwich-panel shear wall should be limited by the maximum axial compression ratio.(4)Combined with the experimental results and statistical analysis,the three-line restoring force model of the restoring force of skeleton curve of the new precast sandwich-panel shear wall was established.The model is based on the analysis of skeleton curve,and through the selection of key points and the method of linear regression,the three-line model can be in good agreement with the test results,providing a theoretical basis for further research of the new precast sandwich-panel shear wall(5)Based on the plasticity damage model,the stress distribution of the shear wall,the failure mode in the loading process,and the load-displacement curve in the results of the finite element simulation all show a good agreement with the test results.The new precast sandwichpanel shear wall show good continuity between the pecast area and delay-pour area,and strong collaborative work ability.The finite element simulation could truly reflect the mechanical characteristics of the specimen under the horizontal load.Finally,the parametric analysis of the key factors was conducted affecting the mechanical properties of the new sandwich-panel shear wall. |
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