Experimental And Theoretical Research On Flexural Behavior Of Prestressed Composite Wall Panels

With the acceleration of China's urbanization process and the continuous reduction of labor resources,it has become a new development direction of the construction industry to use prefabricated buildings to create construction industrialization,reduce environmental pollution,save time limit and save labor force.Steel structure building is more and more popular in the prefabricated building industry because of its features of component factory production and field assembly.The development of floor slab,wall panel and roof panel is the main factor restricting steel structure building.At present,most of the wall panels used in steel structure buildings are block,ALC wall panels and light steel keel wall panels,which have many shortcomings and affect the development of steel structure.Due to its convenient production,high construction efficiency,self-insulation system and many other advantages,composite wallboard has become an ideal wallboard for steel structure building.The weight of composite wallboard directly affects the construction efficiency and time limit.It directly affects the dead weight of the structure,and then the seismic design of the structure.Based on the design of lightweight and high-strength composite wallboard,this paper optimizes the section of traditional flat concrete steel trussed composite wallboard,and makes ribbed concrete composite wallboard to reduce the dead weight of the wallboard.Prestress is applied to the composite wall panel to achieve the design goal of high strength.In order to investigate the performance of a new type of prestressed ribbed concrete composite wallboard,the bending test,theoretical derivation and numerical simulation of the wallboard under uniform loading were carried out.The flexural resistance tests of slab concrete composite wallboard,ribbed concrete composite wallboard and prestressed ribbed concrete composite wallboard were carried out,and the flexural response of composite wallboard including bearing capacity,deflection,failure mode and crack development were investigated,and the influence of weight reduction and prestressing on the mechanical properties of the wallboard was analyzed.The results show that the ribbed concrete composite wallboard can reduce the dead weight of the wallboard while ensuring the bearing capacity of the wallboard.Prestressed ribbed concrete composite wall slab can effectively improve the bearing capacity of wall slab.Compared with the traditional flat composite wallboard,the dead weight of the ribbed composite wallboard with optimized section decreases,and the bearing capacity decreases little compared with the reduced dead weight.While the prestressing wall slab reduces the load,it greatly improves the bearing capacity of the wall slab.Through the analysis of the test data,the change rules of the data of specimen load deflection relationship,concrete strain,steel strain and so on were explored,and the theoretical formula of bending performance of composite wall panel was deduced based on the test phenomenon.Based on the classical elastic beam theory,the theoretical formulas of crack load and crack deflection of composite wall panel are deduced.Based on the theoretical model of flexural member,the ultimate load formula of composite wall panel is derived.According to the formula of minimum error,the coefficient of stress inhomogeneity is put forward.The theoretical value agrees well with the experimental value,which can be used in the application design of composite wall panel.Finite element software was used to simulate the bending state of the specimen,and the test results were compared with the simulation to verify the validity of the model.The optimum design size of composite wall panel is proposed by changing the parameters of concrete model,prestress and concrete panel thickness.