초록 ▼

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-mix

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.

대표청구항 ▼

In apparatus for use in hot mix recycling in which aged asphaltic concrete pavement is removed and sized to provide an aged mix, then heated to a temperature less than the destructive temperature of its old asphalt but sufficient to at least begin its rejuvenation, and thereafter combined with heate

In apparatus for use in hot mix recycling in which aged asphaltic concrete pavement is removed and sized to provide an aged mix, then heated to a temperature less than the destructive temperature of its old asphalt but sufficient to at least begin its rejuvenation, and thereafter combined with heated fresh aggregate and fresh asphalt, the apparatus including a first drum having upstream and downstream axial ends, means for supporting the first drum in an attitude inclining downwardly in a direction from its upstream to its downstream end, means for rotating the first drum about its axis effective together with said inclination to move material introduced into the first drum adjacent its upstream end in said direction to adjacent the downstream end, means to assist retention of material introduced therein as aforesaid on and its elevation by the first drum interior walls during said material movement, and means disposed adjacent the downstream end of the first drum for removal of material therefrom, the improvement comprising: a second drum having corresponding upstream and downstream ends, a downstream portion of the second drum extending into an upstream portion of the first drum through the upstream end thereof, the downstream end of the second drum opening into the first drum, said upstream portion of the first drum spacedly enveloping said downstream portion of the second drum, materiAl in the first drum being introduced into the space between said upstream and downstream portions of the first and second drums, the second drum being supported for rotation about its axis and for movement in said direction of material introduced into the second drum adjacent its upstream end to its downstream end and into the first drum for combination with material in the first drum; and means carried by the interior walls of the second drum effective to assist retention of material introduced therein as aforesaid on and its elevation by the second drum interior walls during said material movement.