Investigation On Properties Of Steel Wool Fiber Reinforced Asphalt Mixture Based On Induction Heating

The electromagnetic induction heating type asphalt mixture is a new type of asphalt pavement construction material,and it has excellent properties such as crack self-healing,snow melting and ice melting.It has broad application prospects and its research is in the ascendant.At present,the technology still has issues such as the applicability and selection of conductive materials,the preparation process of mixed materials,the electromagnetic induction heating characteristics of asphalt mixtures,and the evaluation of comprehensive road performance.In view of this,systematically researching the composition design and performance improvement of the electromagnetic induction heating asphalt mixture has important practical significance.The paper selected steel wool fiber as a conductive material to be incorporated into the asphalt mixture so that the asphalt mixture achieves the purpose of electromagnetic induction heating.By changing the type and amount of fiber,the wheel tracking test,beam bending test,freeze-thaw splitting test were used to study the mixing process and road performance of steel wool fiber asphalt mixture,and the best fiber type based on road performance was recommended.The high-frequency electromagnetic induction heating equipment,infrared temperature measurement and imaging technology were used for heating characteristics analysis.Asphalt mixture electromagnetic induction heating temperature,temperature distribution,induction heating temperature cooling law,longitudinal temperature gradient and so on were quantitatively evaluated.Finally,the comprehensive performance of the asphalt mixture was optimized and improved by using the steel wool fiber / brucite fiber composite method.The road performance and electromagnetic induction heating performance of the prepared composite particle fibers were evaluated,and finally the economic benefits were comprehensively analyzed.The results showed that when the steel wool fiber length was 5cm and the amount was4%(occupied by the volume fraction of asphalt),asphalt mixture had the best road performance.Influence of steel wool fiber content on the heating rate of the asphalt mixture was distinct.During the induction heating process,the asphalt mixture shows a temperature gradient along the longitudinal direction,and the gradient becomes more pronounced with theincrease of the induction heating time.When the induction heating stops,the gradient gradually weakens with the time extending until the temperature tends to be consistent.In the initial period of cooling,temperature in upper layer of the asphalt mixture decreased significantly,while the temperature in lower layer firstly showed a slightly increase process,and then temperature difference got close from the top to the bottom.The whole process of heating up to cooling was affected by the fiber length and volume.When steel fiber and brucite fiber volume ratio is 6/4,mixture had the best performance for optimizing the performance of steel wool fiber asphalt mixture.Based on the electromagnetic induction heating characteristics of steel wool fiber asphalt mixture,the paper aims at the improving of comprehensive performance,optimizing the design from the perspective of material composition,proposing an improved method for existing problems,and verifying the applicability.The research results can provide important reference for the application and promotion of electromagnetic induction heating steel wool fiber asphalt mixture in asphalt pavement engineering.The incorporation of brucite fibers makes the road performance of asphalt mixture further improved,but the electromagnetic induction heating performance is reduced.The composite fiber asphalt mixture has the greatest road performance advantages,its cost is lower than that of the single-blind steel wool fiber,and the cost performance advantage is significant.