If you can blast it off with a power washer, go for it. I hope you are successful, because pulling the old stuff off is going to be a major pain, unless it didn't stick well in the first place. If it did, just get it as clean as you can, smear on the new cement and forget it. If you have thick clumps of old glue, you're going to have to chip or grind unless you don't care about a lumpy carpet.

Geez, don't you need to go fishing? \:\)
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Agendas kill truth.
If it's a crop, plant it.