ABSTRACT
Increased use of RAP in asphalt mixtures has brought forth a need for quantifying the production of RAP mixtures in asphalt plants accurately. Inadequate drying and heating of virgin aggregate in asphalt plant may lead to moisture stripping of RAP mixtures. This study investigates the temperature and moisture evolutions of virgin aggregate in a drum dryer at the particulate scale. This is done by incorporating models of drying and heating for the virgin aggregate into the coupled computational fluid dynamics with discrete element method. The simulation results show that the inlet gas temperature and inclination angle of the drum dryer are the two factors that significantly influence the heating and drying of virgin aggregates, whereas a faster drum rotational speed is beneficial to heat and dry virgin aggregates uniformly. The developed methodology is a promising way to quantify the drying and superheating of virgin aggregate in a drum dryer.
