Preparation And Properties Of Semi-flexible Conductive Pavement Materials

Asphalt pavement is widely used in the modern traffic engineering,highway and airport runway and other traffic arteries are often closed in cold weather due to snow icing,causing a lot of economic losses.However,the commonly used de-icing measures cannot remove the snow and ice in time,and the highly concerned conductive asphalt concrete cannot be effectively applied because the conductive phase materials weaken its pavement performance.Based on the research of traditional conductive asphalt concrete,the semi-flexible conductive pavement material with excellent properties was prepared by pouring conductive cement slurry into the open graded conductive asphalt concrete,the change rule of its electrical properties was studied,and the ice-melting effect was verified.Firstly,by optimizing the composition and performance of graded conductive asphalt concrete and conductive cement slurry,the semi-flexible conductive pavement material was prepared by using large-porosity conductive asphalt concrete and highfluidity conductive cement grouting material(fluidity >11s),and the road performance was tested.The results show that the semi-flexible conductive pavement material has good water damage resistance,low temperature crack resistance and high temperature stability.Secondly,the conductivity of semi-flexible conductive pavement materials and its influencing factors are studied.The results show that the resistivity of semi-flexible conductive pavement material is about 1.80% of that of the matrix material.When the temperature rises to a critical value,the resistance of the specimen mutates.When the temperature drops to a certain degree,the resistance of the specimen tends to be constant.In the 0-90 s after electrification,the resistance of the specimen decreases with the increase of electrification time.After electrification of 90 s,the resistance of the specimen increases.The resistance of the specimen decreases with the increase of voltage.When the voltage increases to the breakdown voltage,the resistance of the specimen decreases to the minimum.When the voltage is greater than the breakdown voltage,a large amount of heat generated within the specimen within a short period of time will lead to the destruction of the conductive path,which will lead to the increase of the specimen resistance.Finally,the surface and internal temperature changes of the specimen during the electrification process were studied by using the infrared thermal imager and the fiber Bragg grating temperature sensor,and the ice-melting effect was verified.The results show that the electric heating process of semi-flexible conductive pavement material can be divided into three stages: rapid heating stage,slow heating stage and heat preservation stage.When the input power was 14.4w,the surface ice of Marshall test piece could be completely melted within 1.5h,and when the input power was 9.9w,the ice completely separated from the test piece at 50 min,indicating that the semi-flexible pavement material had a good ice-melting effect.The semi-flexible conductive pavement material prepared in this study can give consideration to both the conductivity and pavement performance of the pavement material,and can significantly improve the stability of electrical properties of the semiflexible conductive pavement material,which has important practical value for road self-melting ice.