Abstract: Annular lands are mounted on the inner periphery of the tubular shell of a drum for an asphalt mixing apparatus of the type wherein the drum is disposed on a slant and rotated so that flighting arranged about the inner periphery of the drum lifts and drops aggregate and asphalt across the drum to transport the aggregate and asphalt toward the lower end of the drum. Portions of the flighting are mounted in the inner periphery of the shell and portions are mounted on the annular lands. The lands reduce the inside diameter of the drum in selected regions thereof to establish differing advance rates of aggregate and asphalt through the drum in different regions thereof so as to selectively vary the density of veils of asphalt and aggregate across the drum with axial location within the drum.

Abstract: An improved method and apparatus for producing hot mix asphalt wherein flights provided in a mixer drum for cascading aggregate and asphalt across the mixer drum are constructed to establish a plurality of cascade zones, having differing cascade densities, in different portions of the mixer drum. High density cascade zones are provided to maximize the transfer of heat to aggregate; to shield cooler portions of the drum from hotter portions thereof, and to capture fines which would otherwise pass through the drum.

Abstract: An improved method and apparatus for producing hot mix asphalt utilizing new aggregate and a previously manufactured and laid asphalt mix which has been reduced to form recyclable aggregate, wherein the new aggregate is fed into the input end of a rotating mixer drum and cascaded repeatedly through a flame extending from the input end of the mixer drum to a first medial portion thereof and the recyclable aggregate is fed radially into the mixer drum at a second medial portion thereof intermediate the first medial portion and the output end of the mixer drum, the new aggregate shielding the mixer drum from the flame and confining the flame to the portion of the mixer drum between the input end and the first medial portion thereof.