Temperature Control Strategies for Microwave Hot In-Place Recycling of Asphalt Pavements

In order to realize the optimal temperature control for microwave hot in-place recycling of asphalt pavements, the electric field in heating process was solved based on the radio propagation principle, and the equation of heat flow control was established by the theory of permeability plate. The temperature control model was built through coupling between the two equations. The exact solution of the nonhomogeneous linear differential temperature control equation was studied by mathematical analysis method according to the boundary condition during the heating. Effect of electromagnetic and structure parameters on temperature distribution were systematically analyzed. The result indicates that the area ratio between solid and flow dielectric constant have little effect on temperature distribution. However, dielectric loss factor and the value of maximum field strength have remarkable effect on the uniformity of temperature. Temperature field in the asphalt mixtures changes more significant when the parameters are larger. The optimal objective function is built and operation control strategies are researched in two aspects: electrical field, heating method. The result indicates that using 2M210 as heating port is more reasonable than using 2M211. It also shows from experiment that the heating method with 0.5 min's intermission can improve effect of recycling asphalt mixtures.