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 the hot mix method of recycling aged asphaltic concrete pavement which has been removed and sized to provide an aged mix including old asphalt and aggregate, the improvement comprising: providing a stream of hot gases moving in a downstream direction from a source, the hot gas stream at an upstre

In the hot mix method of recycling aged asphaltic concrete pavement which has been removed and sized to provide an aged mix including old asphalt and aggregate, the improvement comprising: providing a stream of hot gases moving in a downstream direction from a source, the hot gas stream at an upstream location having a first temperature greater than the destructive temperature of the old asphalt; introducing a quantity of fresh aggregate into the hot gas stream at said location and heating the fresh aggregate to the first temperature by cascading the same across the hot gas stream while moving the fresh aggregate in said direction; employing a portion of the heat of the hot gas stream to separately heat a quantity of aged mix while moving the same in said direction but apart from the heated fresh aggregate to a second temperature less than the destructive temperature of the old asphalt but sufficient to at least begin restoration of its plasticity; combining and mixing the two heated quantities of the fresh aggregate and the aged mix by introducing the heated aged mix into the stream of hot gases and the heated fresh aggregate at a location downstream of said upstream location to produce a heated quantity of combined mix having a third temperature less than the destructive temperature of the old asphalt; and cascading the combined mix across the hot gas stream while continuing to move the same in said direction and adding a quantity of fresh asphalt thereto to produce a recycled mix, the recycled mix being heated by the hot gas stream to a fourth temperature greater than the third temperature but less than the destructive temperature of the old and the new asphalt.