| With the rapid development of our country and social economy,the energy consumption of our country is more and more high,especially the building energy consumption.More and more high,so our country put forward higher and higher requirements for building energy saving.China has done a lot of work on construction technology,research and application of new thermal insulation materials,and establishment of building energy saving standards.As a very important part of building energy conservation is building envelope,the research and application of building envelope insulation technology is increasingly strengthened.As a developing building technology,the safety performance of building envelope insulation must be paid more attention to,otherwise,it will not only reduce the energy-saving effect,but also cause a great potential safety hazard.Scholars at home and abroad have done a lot of research work on many aspects of the external thermal insulation system,including fire prevention,waterproof,crack and wind pressure,and achieved some results,.At the same time,the foreign thermal insulation technology has developed rapidly and overcome many technical problems,but there is little research on the seismic performance of the external thermal insulation system.However,China is a country with frequent earthquakes.Under the action of earthquakes,the external insulation system will crack and fall off in different degrees,which is easy to cause secondary damage.Therefore,it is very important to study the seismic performance of exterior wall insulation system.At the same time,we think that the frame structure masonry infill wall and paste external insulation system will have a certain impact on the stress of the frame structure.In this paper,the pseudo-static test is carried out on the frame structure with insulation facing layer of filled wall and expanded perlite board,and the comparison with the pure frame structure without filled wall and the frame structure with only masonry filled wall and no insulation facing layer is analyzed.The influence of the filled wall and the external insulation system on the frame structure and the effect ofthe expanded perlite external insulation system under the horizontal earthquake load are obtained According to the failure mechanism,the following conclusions and suggestions are obtained through the experimental study:1.After the frame structure is built with the infilled wall and the expanded perlite board thermal insulation facing layer plus the external thermal insulation system,the stress mechanism will change obviously under the horizontal load,and it is no longer a simple stress form of the frame structure.When the horizontal load is small,the frame works as a whole with the infilled wall and the external insulation system in the initial stage of stress,and its stress is similar to the shear wall.The frame side column is the constraint end column of the shear wall,and the infilled wall bears a large shear force.The overall deformation of the wall frame is no longer the shear deformation of the frame,but the bending deformation similar to the bending of the shear wall.For the frame with infilled wall but without thermal insulation facing layer,when the earthquake horizontal load is large,the infilled wall block will break and fall off.For the frame with thermal insulation facing layer,after the thermal insulation facing layer is pasted,it can strengthen the filling.The facing layer and the filling wall form a rigid body.With the increase of the load,the filling wall and the frame beam and column are separated,which becomes the diagonal brace of the frame,that is,the frame becomes the frame structure with diagonal brace.For this kind of frame structure with diagonal braces,under the action of horizontal load,the frame column will produce a large tensile force,and the shear bearing capacity of column and beam column joints will be reduced,so it is appropriate to have damage.When the load reaches a certain value,the diagonal brace fails,and the stress mode is transformed into frame structure.The side columns on both sides of the component are first subjected to the bending action of the normal section similar to the shear wall structure.The side columns on both sides of the test piece are all under tension or all under pressure respectively.The infilled wall and the external insulation system bear most of the shear force,and there are inclined ladder cracks along the mortar joint.The overall deformation of the wall is no longer the shear deformation of the frame,but the bending deformation similar to the bending of the shear wall.With the continuous destruction of the infilled wall andexternal insulation,the wall and external insulation system gradually quit work,most of the horizontal load is gradually borne by the frame,and its stress form is gradually transformed into the common frame structure stress form.2.After the external insulation system is pasted on the infilled wall of the frame structure,under the earthquake action,the external insulation system greatly enhances the integrity of the infilled wall,the tie bar is easy to be pulled out,and the overall collapse of the infilled wall is easy to occur.The reason for the analysis is that the integrity of the infilled wall is greatly enhanced after the insulation board is pasted.At the later stage of loading,the infilled wall and the external insulation system become the active rigid body in the frame,the tie bar is gradually pulled out,and the infilled wall and the external insulation system as a whole are completely separated from the frame column.It is suggested to strengthen the arrangement of tie bars of infilled wall in practical engineering to prevent the whole wall from collapsing under earthquake.3.After the infilled wall of the frame structure is built,the wall and the whole frame work together,the rigidity and bearing capacity will be greatly improved,and the bearing capacity of the specimen of the infilled wall will be greatly increased.The higher the strength of the infilled wall block is,the higher the overall performance and the greater the rigidity of the specimen due to the external insulation system including leveling mortar,pasting mortar,insulating board and plastering mortar.Therefore,the higher the pasting rate is,the greater the improvement of the bearing capacity is.The bearing capacity of the specimen is further improved by the external insulation system.And because of the different paste rate of external insulation,the load-bearing capacity of the specimen with high paste rate is higher.4.After the frame structure is built with the infilled wall and the external insulation system,its deformation capacity,ductility and energy consumption capacity are all reduced,and the ductility,deformation capacity and energy consumption capacity of the specimen pasted with the external insulation system are further reduced than that of the specimen only built with the infilled wall.That is to say,the masonry filling wall and external insulation system of frame structure are not conducive to the seismic resistance of frame structure.It is suggested that in practical engineering,theinfilled wall should be connected with the frame beam column,and the infilled wall material with soft texture should be selected to enhance the structural deformation and energy dissipation capacity.5.Under the earthquake load,the facing layer of expanded perlite insulation board is easy to break and fall off under the pressure of the corner facing layer of the filling wall.The deformation of the infilled wall and the frame structure is not consistent,the insulation board at the joint surface of the infilled wall and the frame beam column is sheared to produce cracks,and the expanded perlite insulation board veneer layer pasted on the frame beam column should fall off in case of earthquake.It is recommended to use flexible insulation materials on the beam column.The position mainly appears at the joint of frame beam and column and the side of beam and column.The analysis is due to the relative dislocation of frame beam column and wall under the action of earthquake,and the cracks caused by the shear force along the wall received by the insulation board;as well as the pull-out of the tie bar,the separation of the wall and frame column,resulting in the cracks.6.Under the earthquake action,the design qualification and the damage degree of the expanded perlite exterior wall external insulation system veneer layer pasted on the infilled wall have little relationship with the pasting rate and the pasting method,while the seismic resistance of the insulation layer pasted on the frame beam column has great relationship with the pasting rate,so the full pasting method should be adopted. |
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