Study On Mechanical Properties Of Composite Sandwich Insulation Wall Board

With the promotion of the "13th Five-Year Plan",prefabricated buildings have become an important trend in the development of future building technology,and precast concrete sandwich insulation wall panels are more and more widely used in prefabricated buildings.Connector is the most important component of concrete slab on both sides of connecting wall board.The mechanical performance of connecting piece is related to the safety of sandwich wall board.The joint parts in the precast concrete sandwich insulation wall board mainly include metal joint parts and non-metal joint parts.Metal connector pull solid but large heat loss,non-metal connector small heat loss but low shear strength,and the price is high.Therefore,it is urgent to develop a new connection mode with both mechanical properties and thermal properties to meet the requirements of the structural properties and thermal properties of the wall.The new connector made of FRP material has good mechanical properties,and the material itself has poor thermal conductivity,which effectively reduces the cold and hot bridge effect in the wall board.The groove form is a new type of connecting the internal and outside concrete slab to reduce the hot bridge.This thesis,based on key research and development project in Hebei province: the prefabricated ultra-low energy consumption building technology system development(21374502D),developed a new material of concrete sandwich insulation wall plate connection,the integrated use of experimental research and theoretical analysis of the mechanical properties of the connection and configuration of the structure of precast concrete sandwich insulation wall plate performance of the system.And ABAQUS software is used to model the experiment,the main research work and achievements of the thesis are as follows:1.Developed a new type of material insulation wall board —— polyurethane composite sandwich insulation wall board,wall board using lightweight aggregate concrete and modified polyurethane insulation material composite.According to the characteristics of the wall board,the matching modified I-type FRP connector combines the advantages of steel bar and fiber reinforced composite material,and has the advantages of high shear tensile strength,strong anchorage ability,small thermal conductivity,simple processing technology,mass production,convenient construction and so2.Starting from the anti-pull performance,the rod connectors of three different FRP materials,sheet connectors and I-type connections were compared with the same conditions,and the composite material of the insulation wall panels suitable for new materials was selected,and the setting of I-type FRP connector was completed.In addition,the connection mode of the groove form is designed as the wall panels.3.For two different connection mode of such new material insulation wall plate in the shear mechanical performance test study,using I-type FRP connection and groove form respectively,obtained the test load-displacement curve,shear limit bearing capacity,damage form test results,analyzed the damage mode,the mechanical properties influence factors parameter analysis,based on the concrete cone failure of FRP joint bearing capacity and groove connection form of shear bearing capacity calculation formula,and verify the test results.According to the research results of the mechanical properties of the connections,the design method of different connection modes of the composite insulation wall board is put forward for the reference in the design of the I-type connection parts and the groove connection form.In the shear test of composite sandwich insulation wall board,there are three forms of wall board failure:the fracture of the fiber layer of the connector,the fiber fracture of the joint anchor and the anchorage failure,which is the concrete failure of the joint anchor and the concrete failure of the groove.The shear test,the limit load of normal use and bearing capacity of the wall board are 53.257 k N,43.56 KN respectively.The safety evaluation results of the connections prove that the bearing capacity of the wall board and the deformation size of the connections both conform to the specifications,and the safety is high.However,the I-type FRP connector has greater carrying capacity and better anchorage effect.4.The 3 D model of the precast composite sandwich insulation wall board unit was established by ABAQUS software,and the stress and deformation of the new connector were analyzed under shear conditions,and the stress and deformation of the inner and outer leaves were studied.It is concluded that the stress and deformation rules of the single connectors in the whole wall panel unit are basically the same,and the shear bearing capacity of the new connectors in the prefabricated composite sandwich insulation wall board is greatly improved,and the simulation results are compared with The shear bearing capacity has been improved,and the numerical simulation results and the theoretical test results are analyzed to verify the accuracy of the theoretical test.5.Finally,we summarize the mechanical properties of the two connection methods used in the test,analyze the factors that may affect the bearing capacity of composite wall panels,give suggestions,and point out the next research content of the connection method of such composite insulation wall panels.