Using rock salt, like Buckman's ROCK SALT 20KG BAG, on concrete can be effective for melting ice, but it does come with some risks. Over time, rock salt can cause spalling and pitting damage, where small pieces of concrete break off, and surface erosion. It can also lead to corrosion of reinforcing steel within the concrete and deterioration of joint materials. If you're looking for a safer alternative, you might consider using calcium chloride, magnesium chloride, or potassium acetate, which are less damaging to concrete surfaces.