Abstract: A unit for heating initially solid asphaltic material to provide asphaltic concrete in a condition suitable for application. The unit is operated to heat initially cold material to a temperature between 275.degree. and 300.degree. F. and to maintain it at that temperature until it is used. A thermostatic control system produces heated air intermittently in accordance with a predetermined schedule, and the heated air is used to heat the asphaltic material.

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 air flow around the walls of the inner enclosure, infrared energy sources within the latter space for heating air, heating chambers projecting upwardly from the floor of the inner enclosure above the infrared 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 side walls of the inner enclosure for conducting the heated air from the heating chambers to the aforementioned passages. Heat-shielding means are interposed between the infrared sources and adjacent portions of the inner enclosure to prevent local overheating of the material.