Q.: If concrete is frozen, does strength come back? What does freezing do to the finish?
A.: If concrete is frozen before the strength has reached about 500 psi, the strength is likely never to reach its full potential. Freezing does not harm the finish if it occurs after the concrete has reached about the same level of strength—500 psi. If the concrete is frozen before it has attained any significant amount of strength, ice crystals are likely to destroy the finish.