Deepening Research On Performance Test Of Polyurethane Elastomer Used In Bridge Expansion Joint

Polyurethane(PU)elastomers have excellent fatigue properties and low temperature flexibility.They have good bonding properties with concrete substrates,excellent aging resistance and weathering resistance,good cost performance and easy to be constructed.Furthermore,bridge expansion joints are the most easily damaged structural parts of bridge structures.Therefore,the construction codes should be fully valued and improved in real time.Based on the theoretical research on the properties of polyurethane elastomers,this paper optimizes the ultraviolet aging test and low cycle fatigue test for the temporary technical conditions of elastic joints of TJ/GW 120-2013 railway concrete bridge,and optimizes the construction process of polyurethane elastomer expansion joints based on theoretical research.The polyurethane expansion joint technology is further developed.Based on the analysis of the experimental requirements for artificial weathering and ultraviolet aging in the interim technical conditions,based on the analysis of aging principle,material characteristics and test instruments,the paper puts forward suggestions for optimization of the test conditions.Combined with the theoretical analysis of the bridge expansion capacity,the optimization scheme for the low cycle fatigue test of the polyurethane elastomer expansion joint is obtained.The low-temperature properties and glass transition temperature T_g of polyurethane elastomers were theoretically studied.The glass transition temperature T_g of polyurethane elastomers was experimentally obtained,and the low-temperature fatigue properties of polyurethane elastomers were prospected.Through on-site investigation,through sorting out problems and solutions in construction,the construction process of polyurethane elastomer concrete expansion joint is sorted out.Based on the investigation and study of engineering practice,combined with the factors that affect the durability of elastomer material of polyurethane elastomer expansion joint,several suggestions for optimizing the construction technology of polyurethane elastomer expansion joint are put forward.