Q.: We finished an air-entrained concrete ramp at a truck loading dock and left it uncovered late one evening. It rained shortly afterward and surface mortar was washed off. We didn't try to refinish the surface then. What can be done to repair it now?
A.: Repair may not be necessary. Because you didn't attempt to refinish the surface, which would have worked water back into it, the only damage is loss of surface mortar. The slab now has an unplanned exposed aggregate surface. Because it's air-entrained and sloped to drain well, the slab will probably resist freezing and thawing cycles. Repair would ordinarily involve light grinding and scoring to improve traction, but the grainy texture you now have should be adequate for traction. Unless appearance is a problem, which seems unlikely for a loading dock, you may have produced exactly what the owner needs.