Study On Deicing Performance Of Salinized Asphalt Mixture

Road icing in winter will seriously affect road safety,and solving the problem of road icing is the focus of road workers.Salinized asphalt mixture is to add granular or powdered salinized material into asphalt mixture as fine aggregate or filler.Under the influence of vehicle rolling and capillary compaction,the salt is analyzed to reduce the freezing point on the road and solve the problem of road icing.In this paper,the salt materials were evaluated by scanning electron microscope（SEM）and thermogravimetric analysis（TG）,and the chloride content,hygroscopicity,and heat resistance index of the salt materials were tested.The results show that:the content of chloride ion is 46.5%,the heat resistance index is 0.12%,and the moisture absorption rate of the material is 0.4%when it is placed in an 85%constant humidity environment for 2 hours;SEM analysis shows that there is a layer of shell wrapping the slow-release inorganic salt core material on the surface of the polymerized material,which plays a role of slow-release;TG test of N₂and O₂shows that there is no obvious mass loss when the purge gas is N₂;when the purge gas is O₂,there is no obvious mass loss When the temperature is 289℃,the mass loss of the material is the largest,about3.8%,and the material has good thermal stability.Salt material is added to asphalt mixture with equal volume instead of mineral powder,and the optimal mix proportion of salt asphalt mixture is determined by controlling the key index porosity.The high-temperature stability,low-temperature crack resistance,water stability,and ice melting performance of salinized asphalt mixture were tested.The results show that the high-temperature stability of salinized asphalt mixture increases obviously,and the low-temperature cracks resistance and water stability decrease in varying degrees;the salinized asphalt mixture has the effect of reducing freezing point and melting ice and snow.ISE method was used to measure the chloride ion release concentration of saline asphalt mixture,and the release characteristics of effective components of saline asphalt mixture were evaluated by cumulative release concentration and chloride ion precipitation percentage.The influence of asphalt type,void ratio,temperature,and salt content on salt analysis characteristics under static water is explored;the precipitation rate of salt in asphalt mixture under freeze-thaw cycle is studied according to the simulated rainfall scouring the upper surface of the specimen;the results show that different void ratio,temperature,and salt content have a great influence on chloride analysis rate,and asphalt type has less influence on precipitation rate Under the freeze-thaw cycle,the rate of salt analysis is accelerated.Through the bond test device in the MTS loading system,the interfacial bond strength of the saline asphalt mixture is tested.The concentration of ice with the same interfacial bond strength of saline asphalt mixture and common asphalt mixture is taken as the critical release concentration,and the critical chloride ion concentration of saline asphalt mixture is 0.0009mol/L.The long-term performance model of salinized asphalt mixture is established by using the natural soaking method to simulate natural rainfall,heating soaking method to simulate summer rainfall,and freezing-thawing cycle to simulate the influence of winter snowfall.The service life of salinized asphalt mixture is estimated and analyzed according to the rainfall and snowfall in various regions.The minimum service life of salinized asphalt mixture is 1.65 years in Harbin,and the longest service life is in Nanjing 3.52 years.To verify the snow melting and deicing performance of anticoagulant ice material,the test section of the Jiyang expressway was paved.After the alternation of winter and summer,it can play the role of snow melting and deicing.