I must assume you are talking about old hot mix asphalt (HMA)millings or chunks which have been crushed in a crusher. HMA weights vary greatly but 148 lbs per cubic foot is a good average.
If it does weigh 148 lbs/cf, there are 27 cubic feet in one cubic yard, so 27 times 148 would be 3,996 lbs or just about 2 tons per cubic yard. You would need 84 tons (4 large ten wheel dump trucks) to get 42 cy. Check with the supplier for the weight per cubic foot and verify. It could be much lighter depending on where it came from. Compacting the material will also reduce its volume.
If it does weigh 148 lbs/cf, there are 27 cubic feet in one cubic yard, so 27 times 148 would be 3,996 lbs or just about 2 tons per cubic yard. You would need 84 tons (4 large ten wheel dump trucks) to get 42 cy. Check with the supplier for the weight per cubic foot and verify. It could be much lighter depending on where it came from. Compacting the material will also reduce its volume.