Originally posted by DREDIOCK
whats the difference between the two?
I believe he is talking about seal coat. That is where the hot oil (tar) is sprayed on the ground.
Chip seal is the same, but you sprinkle gravel on top.
Cold roll is a mixture of asphault, sand and gravel and can be applied at room temperature. It does not harden until compacted, but is less stable than hot roll because it contains less oil.
Hot roll is what you see most highways paved with. It is a mixture of asphault, rock, sand and fillers. It is laid in layers with a paver at 300*F. It hardens, compacted or not, as it cools. When compacted it is as hard and dense as concrete. There are several different compounds of hot roll.