| Under the strategic goal of sustainable development in China,the application of external insulation system of exterior wall has become the most important way of building energy saving.But in recent years,high-altitude falling accidents of building exterior insulation system are common,which not only affect the beauty and normal use of buildings,but also cause serious safety hazards to pedestrians.Due to its many advantages and wide application,polystyrene board external thermal insulation system has become the first choice in the energy-saving transformation of new residential buildings and old residential areas in China.In China,earthquake occurs frequently.Through the research on the failure form and the mechanical mechanism of the external insulation system of polystyrene board under earthquake,the improvement suggestions are put forward,which is of great significance to improve the safety of the external insulation system.In this thesis,the shaking table test of seismic performance of a three story two span reinforced concrete frame structure with external insulation system of polystyrene board is carried out to explore the failure mode and stress mechanism of the external insulation system of polystyrene board,and the seismic safety of the external insulation system of polystyrene board under different bonding rates and bonding methods.The results are as follows:(1)After the frame structure is built with infilled wall and external thermal insulation system is pasted with polystyrene board,the facing layer,infilled wall and the structure will form a new system to work together to bear the external seismic load,and the mechanical mechanism and dynamic characteristics of the structure will be changed.However,with the increase of seismic intensity,the facing layer is separated from the main structure,the infilled wall is damaged,and the overall working performance is gradually weakened.(2)The existence of infilled wall and external wall insulation system improves the overall stiffness of the structure,reduces the damage degree of the structure,and improves the seismic capacity and collapse resistance of the structure.(3)Under the horizontal earthquake action,the infilled wall and the facing layer participate in the work to form the diagonal bracing effect.The facing layer is inclined to be compressed along the diagonal of the infilled wall,and the facing layer should be damaged at the beam column joint.(4)In the case of high intensity,the structural deformation increases,the deformation of the main frame structure and the infilled wall is inconsistent under the earthquake action,and the relative dislocation occurs,resulting in the cracking and failure of the facing layer at the joint surface.Due to the inconsistent deformation,the shear stress is generated between the thermal insulation facing layer pasted on the frame beam and column and the base,resulting in the bond failure and the separation of the facing layer from the base.Therefore,the facing layer pasted on the main structure should fall off during the earthquake.(5)When the sticking rate is the same,the sticking mode is point sticking method and strip sticking method,and the damage situation is basically the same.Under the same sticking mode,the greater the sticking rate,the closer the polystyrene board external wall external insulation system and the base wall paste.Under the action of ground motion,the degree of the facing layer participating in the stress is higher,and the cracking degree of the facing layer is more serious.(6)The anchor bolt should be added in the frame beam column and the filling wall corner of the external insulation facing layer of polystyrene board to ensure that the facing layer does not fall off even if it is separated from the base,so as to prevent secondary disasters. |
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