Mechanics Research On UHPC-RC High Performance Composite Sandwich Panal

Prefabricated panel is a basic component of precast buildings,an important direction for the development of wall energy conservation,and an inevitable need for the development of building industrialization.It is essential to develop wall panels with light weight,high strength and durability as well as matched heat-insulating connectors that are suitable for composite sandwich panels.Therefore,the shear performance test of FRP-CB thermal insulation connectors,the bending performance test of composite sandwich panels and the numerical simulation of temperature stress of panels under different conditions are carried out for high performance composite sandwich panels in this paper,.First,the FRP-CB insulation connector is designed,and the shear performance tests are carried out on the interface containing the connectors of the composite sandwich panel.The results show that the loading process can be divided into five parts: elastic stage,decline stage,platform stage,strengthening stage and destruction stage.As the number of connectors increases,the overall stiffness of the interface,the elastic phase load capacity,the ultimate bearing capacity,and the ultimate displacement increase.The connector has good overall ductility.Except for the L1-C1 test specimen,the average first peak bearing capacity of each connector is about 13.46kN;the second peak bearing capacity of the connectors has increased by up to 61% compared to the first peak,thus has a certain safety space.When the interface contains a multiple of connectors,each connector is in a part-whole working state,and has a certain spatial effect,so the number of connect ors in each direction when arranging them should not be less than two.Then,the bending performance tests of the full-scale composite sandwich panel with hole on it under the positive pressure and negative pressure is carried out,and the failure mode of the panel is summarized.The plastic limit analysis method using the yield line way of the two-way plate is used to obtain the calculation formula of the flexural capacity of the common UHPC-RC composite panels and UHPC-RW-RC sandwich panels with hole in the middle of them.The performance of the composite sandwich panels is therefore analyzed.The results show that the panel has large bearing capacity and excellent ductility under positive and negative pressure.This composite sandwich panel meets the crack and displacement limitation for the serviceability limit state and the ultimate limit state under normal wind loads.The FRP-CB insulation connector used in the wall panel is not damaged and can meet the bending performance requirements of the wall panel.The failure mode of the wall panel conforms to the failure mode of the four-sided simply supported two-way plate,and has a similar crack development.For UHPC-RW-RC sandwich panels,the calculation number of bearing capacity is 0.31 times of the test results under positive pressure and 0.33 times under negtive pressure by method one,the calculation number of bearing capacity is 1.03 times of the test results under positive pressure and 1.26 times under negtive pressure by method two.Finally,the FEA software ABAQUS was used to simulate the temperature field and stress field of the sandwich panel under high temperature-watering and heating-freezing conditions.Under the influence of environment,the temperature of outer layer changes greatly,while the temperature of inner layer hardly changes.Due to the temperature stress,there is stress concentration at the position where the connector and the wall are intersected and the structural measures need to be strengthened there.The rest of the panel has not reach cracking stress.In addition,the connection between the panel and the main structure should be a flexible structure,which has absorption capability to the temperature deformation of the panel and the connectors.