Theoretical And Experimental Research On Hollow Slab Beam Bridge Reinforced By Steel Plate And Fiber Modified Polymer Concrete

At present,a large number of old Bridges in China have exposed many defects,some even have safety risks,causing serious bridge collapse accidents.In the process of strengthening,new materials and techniques can improve the effect of strengthening.MPC modified polymer concrete is an advanced material with excellent properties.Using the combination reinforcement of steel plate and concrete for reference,replacing the wooden mold with steel mold,and combining with MPC to reinforce the old bridge,not only can have the effect of rapid construction,but also the steel plate can further improve the bending bearing capacity.In this study,the mechanical properties of MPC polymer materials were improved by adding fiber to them to form fiber polymer composite materials,and the flexural bearing capacity and the improvement effect of the overall performance of hollow plate girder bridge reinforced by steel plate-fiber polymer concrete were studied.In this paper,the appropriate fiber type is firstly selected to increase the strength and ductility of MPC polymer material,and the mixing ratio of fiber polymer composite material is designed: the mixing amount of liquid raw material A,liquid raw material B,special Portland cement and fiber;The determination of mechanical properties of fiber polymer composites mainly includes flexural strength,compressive strength and failure mode,as well as the observation of working properties.The structure form of steel plate and solid,the connection mode between steel mould and original beam,the splicing position between steel plates and the rapid assembling technology are designed.Then,the ultimate bearing capacity of hollow slab beam is deduced by analyzing the stress of single beam.The finite element analysis model of prestressed concrete hollow slab beam reinforced by steel plate and fiber polymer concrete was established by ABAQUS,and the parameters such as steel plate thickness,composite material thickness,reinforcement length and width were optimized to analyze the reinforcement effect.The section analysis is carried out by MATLAB program,and the reinforcement scheme is proposed for hollow slab beams with different spansThen,the finite element analysis model of prestressed concrete hollow slab beam reinforced by steel-fiber polymer concrete with damaged hinge joints is established with ABAQUS,and the comparison is made between the model of prestressed concrete hollow slab beam bridge with damaged hinge joints and the model of unreinforced hollow slab beam bridge,so as to analyze the improvement effect of the reinforcement scheme on the transverse distribution performance of the bridge.