Research On The Steel Bridge Deck Pavement Based On High-performance Modified Asphalts

Steel bridge has been pursued by more and more engineers due to its beautiful shape,high strength,convenience of industrial manufacture and standard construction.In order to reduce the construction cost of steel bridge deck pavement,double-layer modified asphalt concrete paving is selected as the research object,and two high-performance modified asphalt binders are used to increase the service life of the paving system.Firstly,the performance of high-strength asphalt(HSA)and high-elasticity asphalt(HEA)are compared with SBS modified asphalt from the perspective of asphalt binder.The temperature sweep test,multi-stress creep recovery test,bending beam rheological test and linear amplitude sweep test are used to research the high temperature performance,low temperature performance and fatigue performance of three modified asphalts.The results show that the high-temperature performance of HSA is outstanding,the low-temperature performance and fatigue performance of HEA is better than the other two asphalts.Secondly,the gradation of the wearing coarse and protecting layer is selected preliminarily according to the characteristics of each layer.The design void of different mixture is determined on the basis of new design concept.The optimum asphalt content is determined based on the Superpave design method.Thirdly,various properties of different high-performance modified asphalt mixtures are studied.The high-temperature anti-rutting performance,low-temperature anti-cracking performance,medium-temperature anti-cracking and fatigue performance are discussed by uniaxial dynamic creep test,trabecular bending test,monotonic load semi-circular bending(SCB)test and dynamic load SCB fatigue test,respectively.Steel bridge deck structure combination designs are proposed for three typical climate zones in China.The recommended paving plans are as followed: the area with harsh high temperature environment could use double-layer HSA concrete,the severe cold area could use double-layer HEA concrete,the area faced with extremely hot and cold weather simultaneously could use ‘HSA concrete wearing coarse + HEA concrete protecting layer’ structure.Finally,the material of waterproof bonding layer is selected and the optimal content is determined through the research of ‘steel plate-waterproof bonding layer’ and ‘waterproof bonding layer-protecting layer’ interfaces.The high-temperature performance and fatigue property of three composite structures are verified by the multi-sequenced repeated load test and five-point loading fatigue test,respectively.The results show that double-layer HSA concrete performs better when dealing with the coupling effect of high temperature and heavy load.The crack resistance performance of the composite structure which use HSA AC-13 as wearing coarse is better,but cracks propagate more rapidly.