I am desperate! We have a new asphalt driveway, and walkway (with red streetprint) that has been stained by a spill of powdered concrete that got wet and hardened.
Is it possible to remove the thin coating of dried concrete that makes the walkway especially look dirty all the time. There are two areas about 3 ft X 3 ft. to be removed.
I think that I would try a sample spot using HCL. Pour some on in a small area and let it stand for a few minutes and flood generously with water. If this disolves the cement without affecting the asphalt surface, tackle the rest of the spill. You can usually purchase hydrocloric acid at home supply stores or pool supply outlets.
.
