Study On Ice Thawing Of Electrothermal Asphalt Concrete On Bridge Deck

Snow led to ice in winter which greatly reduces the friction coefficient of the pavement.It is of growing significance to ensure the safety of road traffic and transportation.Moreover,bridge is the thoroughfare between the two places,which is of great significance.It is the vital to ensure the bridge is unobstructed.The study of snow melting and deicing on bridge deck became a hot toptic.Electrothermal asphalt concrete is a better method for deicing and snow melting,which has the characteristics of green environmental protection and timely snow melting.At present,the research of electrothermal asphalt concrete is focused on the materials instead of its application to bridge deck pavement.Therefore,it is necessary to study on the properties of electrothermal asphalt and its interlayer mechanical properties with cement concrete.A certain amount of graphite and carbon fiber were mixed into asphalt concrete for mix proportion design.The road performance of electrothermal asphalt concrete was tested by indoor test.Then,Outdoor snowmelt and ice melting tests were carried out to obtain the electrothermal performance.Based on that,the temperature stress between the paving layer electrothermal asphalt concrete and the underlayer cement concrete was studied.Finally,numerical simulation was applied to analyze the interlayer stress of electrothermal asphalt concrete bridge deck.The main conclusions are as follows:(1)Graphite and carbon fiber can both play a filling role in the asphalt mixture.Graphite will reduce the overall stability of the asphalt mixture,and carbon fiber can enhance its overall stability.A certain amount of carbon fiber can improve the road performance of asphalt concrete,while graphite will weaken the road performance of asphalt concrete to a certain extent.(2)The resistivity of asphalt concrete can be reduced to a certain extent by adding different proportions of carbon fiber and graphite.The resistivity of the electric asphalt concrete with 0.2%carbon fiber mass and 30%graphite volume is lowest,which can achieve a good electric heating effect with 59.54%heating efficiency.(3)The temperature stress of nodes increases gradually with the increase of temperature.The maximum interlayer temperature stress comes to 0.6MPa after electrified 4 hours.The interlayer temperature stress is higher when the temperature is low.Besides,the faster temperature stress increases when the voltage is higher.The larger wind speed is,the interlayer temperature stress smaller is.(4)With the increase of the surface thickness,the interlaminar tensile stress gradually decreases,the interlaminar shear stress increases gradually,and the temperature growth rate decreases.It is recommended to select the ordinary asphalt concrete 4cm of upper layer and 6cm of lower layer for the surface thickness plan.