Temperature field of asphalt mixture based on microwave heating

To improve regeneration quality of asphalt mixture through microwave heating, the main parameters that influence temperature field distribution is explored by analysing horn antenna radiation electromagnetic field and heat conduction model of the asphalt mixture. Seven types of horn antenna with different aperture plane sizes and lengths were used for simulation. The results are as follows: (1) the more similar the lengths of the aperture plane's long and short sides are, the more average temperature field distribution is, and (2) the antenna lengths in H and E planes have minimal influence on temperature field distribution. The microwave heating experiments with different powers revealed that after improving the microwave power, the speed of elevated temperature becomes more obvious, but the temperature field distribution becomes less uniform. A comparison of continuous microwave heating and intermittent microwave heating experiments shows that the intermittent heating method could improve the uniformity of temperature distribution, but energy loss is more than that of continuous microwave heating. The findings have a guiding significance for the choice of structure perfection of horn antenna and heating method, which finally could improve the regeneration quality of the asphalt mixture.