Abstract: A drum aggregate drier and a drum mixer for making asphaltic concrete feature heat shields between circumferentially adjacent flights inside the drum along the radiant zone of the burner flame in order to minimize drum overheating, heat loss and drum wall wear.

Abstract: A drum mixer for recycling old asphalt pavement features a stationary shroud enveloping a series of circumferentially spaced feed ports medially of the drum. The old pavement is introduced tangentially into the shroud and then into a series of "hoppers" within the shroud formed about the feed ports and revolving with the drum. The old pavement falls through the feed ports onto the exterior of a conical inner drum and is directed to the downstream end of the latter by flighting thereon where it joins virgin aggregate emerging from the interior of the inner drum.

Abstract: A method of hot mix recycling of old asphaltic concrete paving heats the old pavement, after it has been removed and sized, to a temperature below its firing point and heats fresh aggregate to a greater temperature before combining the two and adding new asphalt. The method is embodied in a drum-mixer type of apparatus modified by inserting a smaller drum in the upstream portion of the large drum. The burner fires into the smaller drum into which the fresh aggregate only is introduced while the old mix (plus additional fresh aggregate in certain cases) is introduced into the annular space between the two drums, the fresh aggregate and the old mix being thereafter combined in the large drum, new asphalt added and the mix further heated.

Abstract: A method of hot mix recycling of old asphaltic concrete paving heats the old pavement, after it has been removed and sized, to a temperature below its firing point and heats fresh aggregate to a greater temperature before combining the two and adding new asphalt. The method is embodied in a drum-mixer type of apparatus modified by inserting a smaller drum in the upstream portion of the large drum. The burner fires into the smaller drum into which the fresh aggregate only is introduced while the old mix (plus additional fresh aggregate in certain cases) is introduced into the annular space between the two drums, the fresh aggregate and the old mix being thereafter combined in the large drum, new asphalt added and the mix further heated.