Optimization Design Research On Deck Surfacing Materials & Structure For Steel-box Girder Bridge

Steel deck pavement is one of the key technologies in the construction of large-span steel girder bridge and has been highly valued and concered by the world of academics and engineers at home and abroad.The construction craze has started since 90s of the 20th century in domestic.However, effective paving materials and pavement structure has not been formed up to now according to the service conditions of dozens of bridges.Up to less than lifespan,it happened slipping,bulge and breakage disease problems etc. Steel box girder pavement is still a global technological problems.The paper first summarized the domestic and foreign steel girder bridge pavement technologies, and penetratingly analysized the loading characteristics, functional requirements, common failure modes and diseases of the steel girder bridge pavement .On this basis, two new types of materials and structures was put forworded for steel-box girder bridge pavement programs. Flexible surfacing materials pavement program ,specificly includes the two-layer high viscosity modified asphalt SMA and roughing inerface, the below-layer of mastic high viscosity modified asphalt concrete and the top-layer of high viscosity modified asphalt SMA13, below-layer of epoxy asphalt concrete and top-layer of high viscosity modified asphalt SMA13. Rigid surfacing materials pavement program based on high-toughness lightweight concrete lower-layer, shear connectors, reinforced net, good overall deformation performances.Established a 3-D finite element model of mechanics analysis by finite element analysis software ANSYS to the above two types of steel box girder deck pavement, and did feasibility analysis to the pavement program in theory presented in this paper. Using the maximum horizontal tensile stress (σ_xmax) of the surface pavement and the maximum horizontal shear stress (τ_xmax) between the lower-layer pavement and the steel bridge deck as mechanical controlling norms and combining indoor interface pullout and the vertical shear test results, this pavement program has good adaptability.Utilizing the high viscosity of modified asphalt and mix fiber strengthening and toughening technology , improved the high-temperature stability , low-temperature cracking, water stability and other road performance of the SMA asphalt mixture. Optimized the asphalt mixture that can meet long-span steel box girder bridge pavement design requirements.Utilizing steel fiber, organic fiber,polymer and other advanced cement based composite toughening means, aiming to the predominant problem of large brittle of lightweight concrete, did toughening and its basic physical mechanical properties and performance research, preparaed one kind of high toughnees and lightweight concrete that can meet the requirements of the steel bridge pavement and combine the structure and function together. Studied the static load test and fatigue performance tests of the small composite trabecular, qualitative forecasted and analysized the long-term application performance of the pavement program.This pavement programs have successfully carried on the Wuhan Baishazhou steel bridge pavement partial restoration project, Wuhan City Central Link steel girder viaduct bridge, has taken good economical and social efficiency.