Mechanical Analysis Of Epoxy Asphalt Steel Bridge Deck Pavement Structure And Experimental Study Of Pavement Interfacial Performance

The stress and deformation level of steel deck pavement is significantly higher than that of ordinary road surfaces.In recent years,the number of long-span bridges using orthotropic steel decks has increased,especially for continuous steel box girder bridges in many river-crossing,sea-crossing and viaduct bridges.For large-scale applications,it is necessary to conduct a comparative study on the difference of the steel deck paving forces of suspension bridges,cable-stayed bridges,continuous beam bridges and other bridges.The investigation of steel bridge deck pavement diseases shows that the transition and delamination between pavement layers caused by insufficient bonding strength or failure of the bonding layer are more typical diseases.It is necessary to further study the factors and mechanisms of the bonding performance between pavement layers.The pavement structure will produce shear stress and tensile stress under the action of vehicle load.It is necessary to grasp the analysis of the stress state of the pavement structure of different bridge types under different temperatures and vehicle loads to provide a basis for the design of paving materials and structures.The bonding layer,as a functional layer for bonding between the pavement layers,the pavement layer and the steel bridge deck,has an important impact on the performance and fatigue life of the pavement structure.Starting from the composite structure system integrating the upper pavement,the bonding layer,the lower pavement and the steel bridge deck,the factors and mechanisms affecting the bond strength of the composite interface are studied and evaluated.Combined with the steel bridge deck paving project of the deep and medium passage project,the finite element software Ansys is used to analyze the stress state of the suspension bridge,cable-stayed bridge and continuous beam bridge involved in the project.The results show that the strain distribution laws of the three bridge types are similar,The strain level of the pavement layer is mainly related to the spacing of the diaphragm,the distribution of the orthotropic bridge deck and the load arrangement,and the strain level of the three bridge types has no significant difference.Combining the theory of interfacial bonding and the mechanism of bonding between pavements,the contact infiltration process of the interlayer adhesive and asphalt mixture is analyzed,and the microscopic morphology of the interfacial bonding layer of the steel bridge deck pavement and the epoxy asphalt mixture is analyzed.The cross-sectional shape of the pavement layer shows that during the paving and compaction process,the bonding layer undergoes a molten state,and infiltrates into the asphalt mixture and penetrates into the mixture along with the voids,forming a complex composite bonding interface.The adhesive forms the interface bonding strength through mechanical occlusion and chemical bonding.The dynamic shear rheological test was used to analyze the rheological properties of the interactive interface material of the pavement structure combination interlayer mixture cement and epoxy resin adhesive.The results show that the interaction between the mixture cement and the epoxy resin adhesive.The effect will reduce the linear viscoelastic range and glass transition temperature of the binder.As the temperature increases,the modulus of the interface material decreases;the interaction between the epoxy asphalt mixture binder and the epoxy resin binder at the interface is closer,and the ability to resist deformation at high temperatures is enhanced.The master curve analysis based on the parameters of the Sigmodal model shows that the interface of the epoxy asphalt pavement structure has good bonding performance,high temperature stability and resistance to shear failure.Through the analysis of the interlayer shear stress and the top surface stress of the continuous beam bridge SMA+EA and EA+EA pavement structure combination,the interlayer and top surface stress of the SMA+EA pavement structure are higher than the EA+EA pavement structure.Top layer EA-10F(fine gradation)+ lower layer EA-10F(fine gradation)pavement structure bonding layer optimal dosage is 0.6kg/m2,upper layer EA-10C(coarse gradation)+ lower layer EA-10F(fine-graded)pavement structure bonding layer optimal dosage is 0.8kg/m2.The effect of fillers on the performance of epoxy asphalt mixture and the bonding performance between pavement layers has been experimentally studied,and it is shown that finer fillers can improve the tensile strength and interlayer bonding performance of epoxy asphalt mortar.In the design of steel bridge deck pavement,it is necessary to comprehensively consider the stress state of the pavement layer and the interlayer bonding effect,and carry out the integrated design of the pavement structure.The use of finer gradation and appropriate amount of bonding layer can increase the bonding strength between pavement structures and increase the integrity and service life of the pavement structure.The research in this paper can provide references for structural analysis of steel bridge deck pavement,epoxy resin waterproof bonding layer design and construction control.