Abstract: A unit for heating initially solid asphaltic material to provide asphaltic concrete in a condition suitable for application, including an inner enclosure defining a volume for containing the material to be heated, an outer enclosure surrounding and spaced from the inner enclosure to define a space beneath the inner enclosure and passages for heated air flow around the walls of the inner enclosure, a screw disposed in an open-top channel at the floor of the inner enclosure to move heated material, an opening in the inner enclosure floor in communication with a passage in the outer enclosure floor for delivery of heated asphaltic material moved by the screw to the unit exterior, heating chambers projecting upwardly from the floor of the inner enclosure above the heating sources to provide regions through which hot air rises from the sources, and flues extending transversely from the upper portions of the heating chamber to the end walls of the inner enclosure for conducting the heated air from the heating chamb