Analysis of Reclaimed Asphalt Pavement Heating with Microwave Radiation

The research focuses on the analysis of potential use of microwave radiation as alternative Reclaimed Asphalt Pavement (RAP) heating method. Material characteristics and the microwave heating possibility for the production of Hot Mix Asphalt (HMA) were verified. The research focused on testing HMA with different content of RAP and RAP of different moisture containing unmodified bitumen and modified bitumen with styrene-butadiene-styrene (SBS) polymer. Tests for density, bulk density, air void content and the Indirect Tensile Strength were carried out. The test results confirmed the possibility of using microwaves to heat the HMA without adversely affecting its basic properties. The research also shows the possibility of heating the RAP in the process of HMA production, especially with the RAP of a moisture content above 3%. In addition, the tests of HMA did not reveal any negative impact of microwave heating in the case of using moist RAP for the production of HMA. The susceptibility of the SBS polymer to microwave radiation was indicated by comparing the behavior of the two HMA types under its influence. HMA containing modified bitumen appears to achieve higher temperatures than HMA with unmodified bitumen after the same time of microwave heating.