| Road deicing has always been a hot issue by domestic and foreign traffic maintenance departments.In winter,the ice and snow cover reduces the friction coefficient of the road surface and the vehicle braking effect is insufficient,which leads to frequent traffic accidents in winter.In order to effectively solve the problem,the electromagnetic induction heating technology is introduced,and the applicability of new deicing technology for asphalt pavement is systematically evaluated.In this paper,steel wool fiber was selected as induction heating material to be mixed into asphalt mixture,and the road performance and deicing performance of steel wool fiber asphalt mixture based on induction heating were studied.Firstly,the influence of the length and content of steel wool fiber on the high temperature stability,low temperature crack resistance and water stability of asphalt mixture was studied.Secondly,with electromagnetic induction heating equipment and reasonable setting of test parameters,the paper analyzed the influence of the length and content of steel wool fiber,ice thickness,output current,ambient temperature and other factors on the deicing performance of asphalt mixture under induction heating.The significance of the factors affecting the average melting ice rate of asphalt mixture was determined by using the method of grey entropy analysis,on this basis,a prediction model for deicing rate of steel wool fiber asphalt mixture based on BP neural network was constructed.Finally,the effect of different slopes on the deicing efficiency of induction heating of asphalt mixture was simulated,and the deicing mechanism of induction heating of steel wool fiber asphalt mixture was further explained.The results show that the steel wool fiber can improve the high-temperature stability and low-temperature crack resistance of asphalt mixture,the water stability is slightly decreased but still meet the requirements of current specifications,and the road performance of 5mm steel wool fiber asphalt mixture with 4%content is the best.The steel wool fiber asphalt mixture heated by electromagnetic induction obtained satisfactory result according to engineering test,and the average melting ice rate of asphalt mixture containing 6%steel wool fiber with length of 5 mm is the highest,0.47℃·s-1.The length and content of steel wool fiber,ambient temperature and output current have positive correlation with the average melting ice rate of induction heating,while the thickness ice layer thickness has negative correlation with the average melting ice rate.The influence degree of five factors on the average melting ice rate of asphalt mixture is as follows:fiber content,fiber length,output current,ambient temperature,and ice thickness.BP neural network model is feasible to predict the change rule of the average melting ice rate of asphalt mixture under different influence factors,and the prediction result offers some reference value.The deicing time decreased with the increase of simulated slope,and the minimum deicing time is 4.6min at25°slope,which improved the deicing efficiency by 43.9%.The mechanism of deicing by induction heating is that the heat generated by induction heating of steel wool fiber in asphalt mixture is finally transmitted to the interface between asphalt mixture and ice layer by means of heat transfer,so as to reduce the adhesion between the ice layer and the surface of asphalt mixture,and then deicing can be easily carried out.The research results provide a new way to solve the problem of driving safety of asphalt pavement caused by winter snow cover. |
