Axial Compression Test And Bearing Capacity Study Of Externally Insulated Single-sided Laminated Shear Wall

With the development of China’s assembly structure system and the promotion of building energy conservation,the laminated shear wall structure is widely used,of which the external insulation single-sided laminated shear wall because it can realize the integration of structure and insulation,so that the insulation system and the structure with the same life cycle,become the focus of the future development of China’s building energy-saving wall.Axial compression as the basic force state of structural members,the study of the basic law of axial compression mechanical properties of laminated shear walls is the basis for further study of the structure in compression shear,compression bending and other complex force state performance.The existing research results show that the damage of the laminated structure often starts from the bond damage of the laminated surface,so it is necessary to further study the complex force transmission mechanism and damage mechanism of the laminated surface,and investigate whether the laminated surface can meet the bearing capacity requirements under the action of axial pressure.The purpose of this paper is to study the mechanical properties of single-sided laminated shear walls with external insulation in axial pressure,and to analyze the factors influencing the performance of laminated shear walls in axial pressure and the stress mechanism of laminated surfaces through a combination of experimental research,finite element simulation and theoretical analysis.The main research work and results of this paper are as follows:(1)Through the axial compression test of single-side laminated shear wall with different height-thickness ratios of external insulation on two sides,the crack development law,damage morphology,load-displacement curve,bearing capacity and axial compression stiffness and other mechanical properties of the two specimens were obtained,and the results showed that the interface truss reinforcement can play an effective role in tensioning the prefabricated inner panel,which can meet the bearing capacity and reliability of the laminated surface,and the connection of the external insulation panel with adhesive-anchor connection is firmly connected to meet the requirements under normal use condition.The stress state of the positive section of the two specimens was analyzed to examine the changes in the ratio of the axial force sharing between the cast-in-place concrete in the middle of the laminated wall slab,the precast inner sheet and the concealed columns on both sides during the loading process of the specimens.(2)Based on the axial compression test of the single-sided laminated shear wall with external insulation,the finite element simulation software ABAQUS was used to establish the refined model of the above specimen and analyze its axial compression mechanical properties,and the analysis results were compared with the test results,and it was found that the results of concrete plastic damage,reinforcement stress distribution and load-vertical displacement curves of both were basically the same,thus verifying the The accuracy and validity of the finite element model were verified.The finite element model was used to further analyze the force transfer mechanism of the old and new concrete laminated surfaces and the slip deformation of the external insulation slab,and the results showed that the interface connection settings of the two laminated surfaces met the load-bearing capacity requirements.(3)Based on the experimental study and finite element simulation results,the effects of each parameter variable,such as concrete strength,height-to-thickness ratio,number of interface truss reinforcement and number of interface connectors,on the axial compression performance of the externally insulated single-sided stacked shear wall are further investigated.Combined with the existing literature codes,an interface combination factor is introduced to characterize the effect of the number of interface joist reinforcement on the overall bearing performance of the stacked shear wall,and finally an axial compressive bearing capacity calculation formula is proposed for this exterior insulated single-sided stacked shear wall,which provides some reference for future practical engineering applications.(4)Combined with the force characteristics of the external insulation single-sided laminated shear wall,the design method of the interface connection between the new and old concrete laminated surface and the external insulation panel joint surface is proposed respectively,the number,arrangement form and arrangement spacing of the interface connections are determined,and finally the safety of the wall panel engineering application is tested to explore the applicability of the calculation method and provide a basis for the design.