Study On Out Of Plane Seismic Behavior Of Assembly AAC Masonry Infilled Wall

Infilled wall frame structure is widely used in civil building.It is composed of infilled wall and reinforced concrete frame,which has the advantages of flexible layout and economical.But through practical engineering application and seismic damage data,it can be found that many problems still exist in infilled wall frame structure.First,the traditional masonry infilled wall has large self weight and poor tensile property,and it is easy to destroy and collapse under the earthquake.Secondly,the connection between the traditional masonry infilled wall and the frame is mostly rigid connection,which causes the masonry infilled wall in the frame plane to bear greater internal force under the earthquake.It will have an unpredictable effect on the stiffness distribution and the weak layer distribution of the whole structure,which makes the structural design deviate from the actual.At last,the traditional masonry infilled wall is mainly built on the site after the frame main structure is completed.This makes the construction period lengthening and low construction efficiency,on the other hand.The quality of site construction is difficult to guarantee,and will cause certain pollution and construction waste.In order to solve the problems of the infilled wall frame structure and improve seismic performance of this type of structure.Assembly AAC masonry infilled wall is put forward,in which AAC is the abbreviation of autoclaved aerated concrete,and seismic performance and failure mechanism of its outside plane are studied by test,and then based on the test results.The formula and design method of out of plane bearing capacity of assembly AAC masonry infilled wall are given.The main work of this paper is as follows:(1)Based on extensive literature and extensive investigation,assembly AAC masonry infilled wall is proposed in this paper,which is made from prefabricated AAC masonry wall panels as the basic unit.The prefabricated AAC masonry wall panels are made in the factory,consisting of autoclaved aerated concrete block,special masonry mortar,protective mortar,transverse anchorage bar and longitudinal reinforced bar.Assembly AAC masonry infilled wall has a light weight,greatly reduces the wet work amount in the field and improves the construction efficiency.In addition,the wall panel in the factory ensures the quality of the infilled wall and saves the time limit.(2)Bending test of 5 prefabricated AAC masonry walls under uniform loading are carried out to study the flexural performance of different structural prefabricated masonry walls,and to reveal the failure mechanism of the wall panel bending,and to provide a basis for the calculation formula of the flexural capacity of prefabricated AAC masonry walls.The test results show that the prefabricated AAC masonry wall panel can meet the requirements for the bending bearing capacity of the code.The longitudinal reinforcement ratio and the layout of the steel bar are the main factors affecting the flexural capacity of the wall panel.(3)With ratio of height to thickness and wall-frame connection(two kinds of flexible connection)as the test factors,four 1:2 scale assembly AAC masonry infilled wall frames are designed.The unidirectional static loading tests of air bags are carried out to study the aseismic performance of the assembly AAC masonry infilled wall and to reveal the outside failure mechanism of the infilled wall.It provides a basis for the calculation model of the out of plane bearing capacity of assembly AAC masonry infilled wall.The test results show that the assembly AAC masonry infilled wall is shown as a single one side panel stress mode.After cracking,three hinged arch bearing mechanism will be formed.The ratio of height to thickness is inverse proportional to the out of plane bearing capacity.Compared with the groove type connector,the L type connector is weak to restrict the upper part of the infilled wall.Obviously,it will cause the integral wall collapse due to the failure of the upper part.(4).Based on the test results of wallboard bending test and out of plane static loading test of the wall,and referring to the relevant norms and the predecessors'calculation formula for calculating out of plane bearing capacity of the infilled wall,the formula of the flexural capacity of the prefabricated AAC masonry wallboard and the formula of the out of plane bearing capacity of assembly AAC masonry infilled wall are put forward in this paper.Then compare to the calculation value and the test value can be obtained:the calculation bearing capacity is smaller than the test bearing capacity.Considering the cause of error,the calculation bearing capacity is in good agreement with the test bearing capacity;in addition,the calculation bearing capacity and the test bearing capacity change trend is completely.Rationality of the formula is verified.(5)On the basis of the formula of bearing capacity,the design method of assembly AAC masonry infilled wall is given in this paper.The realization process of the design method is illustrated by an example of checking and designing.The results show that assembled AAC masonry infilled wall designed through the design method can meet the corresponding seismic performance requirements.The design method can be effectively applied to engineering.