Experimental Study On Fiber Toughening Technology Of Epoxy Asphalt Mixture For Long Span Steel Bridge Deck

Epoxy asphalt mixture is mainly used in the pavement of long span steel bridge decks.Heavy load traffic and orthotropic structural characteristics of steel bridge decks proposed high requirements for the deformation performance,material strength,and fatigue performance of epoxy asphalt mixture.The pavement of epoxy asphalt mixture has problems such as cracking,fatigue damage etc.Therefore,this paper reinforces epoxy asphalt mixture to meet the requirements of anti-cracking,anti-fatigue etc.,and study the reinforcing effect of different fibers(basalt fiber,glass fiber,polyester fiber)on the epoxy asphalt mixture.Firstly,viscosity and tensile tests were conducted on epoxy asphalt to determine its construction temperature and elongation at break.Through Marshall test,the mixture design of EA-10 epoxy asphalt mixtures with basalt fiber,glass fiber,and polyester fiber and without fiber were carried out to determine the mineral composition and optimal oil-stone ratio of four types of EA-10 epoxy asphalt mixture.The research results show that the retention time and tensile strength of epoxy asphalt meet the engineering requirements,and the optimal oil-stone ratio of the epoxy asphalt mixture without fiber and with basalt fiber,glass fiber,polyester fiber is 6.5%,6.7%,6.6%,and 6.8%.Secondly,the road performance of four types of EA-10 epoxy asphalt mixtures was studied through rutting tests,low-temperature small beam tests,immersed Marshall tests,freeze-thaw splitting tests,oil and corrosion resistance tests,and slip resistance tests.The results show that compared with the mixture without fiber,fibers have good effects on improving high-temperature rutting and low-temperature crack resistance,and their water stability performance is also enhanced to a certain extent.It indicates that fibers can improve the road performance of the mixture,and basalt fiber has the best improvement effect.Then,through impact tests,fatigue tests,and ultraviolet(UV)aging small beam bending tests were adopted to analyze the toughening effects of four types of EA-10 epoxy asphalt mixtures.The results show that the impact toughness of epoxy asphalt mixtures was significantly affected by medium and low temperatures and fiber types.The fatigue life of epoxy asphalt mixtures under 1000με decreases significantly.The maximum bending tensile strain of the epoxy asphalt mixture decreases to a large extent after 21D days of ultraviolet aging.Adding fibers can increase the impact toughness,high strain fatigue life,and delay the attenuation of ultraviolet aging of the epoxy asphalt mixture.Finally,the influence of fibers on the crack resistance of epoxy asphalt mixture was studied through semi-circular bending tensile test,digital image technology,and environmental scanning electron microscopy test.The results indicate that temperature and fiber type can affect the cracking mode of epoxy asphalt mixture.At low temperatures,fibers can enhance the stiffness of epoxy asphalt mixture,delay the fracture time,and at medium temperatures,fibers can decrease the crack propagation rate after cracking and hinder the original crack propagation path.The research results of this article provide scientific basis for guiding the application of fibers in epoxy asphalt mixtures,and provide reference for the research on fiber toughening technology of epoxy asphalt mixtures.