Q.: A contractor applied a broom finish to a driveway but because the weather was cold he placed kraft paper over it and covered it with salt hay. In some places the paper became pressed into the surface enough to make the surface smooth. Will these smooth areas be more subject to scaling and spalling?
A.: Air entrainment was not mentioned. If the concrete mix had a sufficient air content and if the concrete was placed at a slump of no more than 4 inches the more critical considerations for freeze-thaw durability have been taken care of. (It would also help if the concrete had a chance to dry for 28 days between the end of curing and the beginning of winter, and if no deicers were applied the first winter.) The smoothness of the surface should have virtually no effect on scaling and spalling.