Study On Mechanical Properties Of Polyurethane-based Fiber-reinforced Elastic Concrete And Its Application In Continuous Structure Of Bridge Deck

This study takes the continuous structure of simply-supported bridge deck as the object,carries out the research based on the mechanical properties of polyurethane-based fiber-reinforced elastic concrete and its application in the continuous structure of bridge deck.Through the mix proportion design and mechanical test of polyurethane-based fiber-reinforced elastic concrete,the influences of different influencing factors on its mechanical properties are analyzed,and the best mix proportion is finally determined.Through the finite element analysis of continuous structure of polyurethane concrete bridge deck,the stress and deformation characteristics under different working conditions are obtained,and the feasibility of using polyurethane-based fiber-reinforced elastic concrete as material for continuous structure of bridge deck is verified,and the sensitivity of parameters for continuous structure of bridge deck is analyzed.This paper mainly studies the preparation and mechanical test of polyurethane-based fiber-reinforced elastic concrete,the mix proportion design of polyurethane-based fiber-reinforced elastic concrete and the finite element analysis of continuous structure of polyurethane concrete bridge deck.Firstly,the compositions of polyurethane-based fiber-reinforced elastic concrete are introduced.According to the two-component synthesis characteristics of polyurethane and its reactivity with water,the preparation process of polyurethane-based fiber-reinforced elastic concrete specimen is set.Taking the compressive strength,flexural strength and workability as evaluation indexes,and referring relevant specifications,the mechanical test methods of polyurethane-based fiber-reinforced elastic concrete are defined.Secondly,the best mix proportion of polyurethane-based fiber-reinforced elastic concrete is designed by considering the three factors of glue-bone ratio,cement proportion and fiber content.A comprehensive experimental design is adopted to carry out the two factor mix proportion design of polyurethane-based fiber-reinforced elastic concrete,and the influences of glue-bone ratio and cement proportion on the strength and deformation performance of polyurethane-based fiber-reinforced elastic concrete are analyzed.The orthogonal experimental design is adopted to carry out the three factor mix proportion design of polyurethane-based fiber-einforced elastic concrete.The influences of glue-one ratio,cement proportion and fiber content on the strength and deformation performance of polyurethane-ased fiber-einforced elastic concrete are analyzed.The rules of mechanical properties are summarized,and the best mix proportion is finally determined.Finally,the finite element analysis of the continuous structure of polyurethane concrete bridge deck is carried out.Taking the prefabricated post tensioned prestressed concrete simply-upported hollow slab bridge as the engineering background,referring to the relevant specifications and existing design,the model of the continuous structure of polyurethane concrete bridge deck is established by using ABAQUS finite element software.Through the finite element analysis of continuous structure of polyurethane concrete bridge deck,the stress and deformation characteristics of continuous structure of bridge deck under different working conditions are obtained,and the feasibility of using polyurethane-based fiber-reinforced elastic concrete as material for continuous structure of bridge deck is verified,and the sensitivity of parameters for continuous structure of bridge deck is analyzed,the rules of parameters are summarized and the design suggestions are put forward.