Heating characteristics of microwave-absorbing asphalt mixture
As a kind of industrial waste, steel slag contains some metal oxides, especially transition metal oxide Fe2O3, and has strong microwave absorption ability. This not only can effectively improve the utilization rate of steel slag to avoid environmental pollution, but also can significantly enhance the absorbing ability of asphalt mixture. CIP is a kind of magnetic metal powder, obtained by pentacarbonyliron decomposition. CIP has the characteristics of high magnetic permeability, low coercive force and cheap price (Zivkovic & Murk 2012). Besides, CIP has large specific surface area and good temperature stability, so that it can guarantee the warming
Early damage occurs in asphalt road due to environmental effects and heavy loads after a few years open to traffic. And it will accelerate if there is no repair in time. The majority of damage is the result of material properties themselves instead of the road structure. For this reason, a perfect timing to make preventive repairs can prolong the service life of road effectively. As an organic polymer, asphalt has reversible thermal properties of dissolution and precipitation, which explains the self-healing of asphalt. Study shows (Little & Bhasin 2007) that healing occurs after the load that generated the damage has been removed, because of the diffusion of the molecules between the two sides of the crack. It is also well known that the amount of healing increases when the material is subjected to a higher temperature during the rest period (Daniel & Kim 2001). Heating can lead to better healing of asphalt road. Conventional method is the infrared heating through heat conduction. The penetration depth is shallow and the temperature distribution is not uniform. The pavement surface may be overheated and result in fatal asphalt fumes (Terrel et al.1997).