Abstract: Fragmented old asphaltic concrete or the like is recycled into new hot-mix by temporarily separating larger pieces from the smaller fragments, generating heat internally within the large pieces with penetrating microwave energy, separately heating the smaller fragments by exposure to hot gas, and then recombining and remixing the separately heated components. The old concrete can be heated very rapidly, highly uniformly and economically while avoiding asphalt degradation and pollution problems that can be caused by exposure to extreme high temperature and while avoiding the relatively high costs of heating the entire volume with microwave energy.