If you are like me, every time I think of applying salt or an ice melt product on my concrete driveway, I ask myself if it will hurt the concrete. After some research and years of experience, my answer to this question is not an easy yes or no. It depends on the age of the concrete, the quality of the concrete, the installation of the concrete, the ice melt used, and whether the driveway has been sealed. Concrete is naturally very porous and readily absorbs water. When water soaks into the concrete and it freezes, it expands and tries to expand and crack the concrete. When the concrete is of a low quality and has a low amount of cement, the surface can crack and pop off. Also, some of the ice melts are more harsh than others on concrete. Some ice melting chemicals, over time, will break the bond between the cement, sand, and gravel. Without going into all of the detail and chemistry for each ice melt, I will provide my recommendation on using ice melts.
To start, prevent as much moisture as possible from soaking into your concrete surface by applying a good quality concrete sealer. This has to be done when the temperature of the concrete is 65F or above. Sealers are sold at local hardware stores. A concrete sealer will prevent much of the water and ice melt chemical from soaking into your driveway/walk. The best overall ice melt product to use is calcium chloride. It melts ice well, is less harmful to plant life, and is less corrosive to concrete. Try to use the calcium chloride as sparingly as possible and still get the job done. Ice melts are intended to break the bond between the ice and the concrete surface so it can be removed easily. It is not meant to be applied and reapplied to melt and dry the surface all by itself. Calcium chloride is more expensive than most of the other products, but when you think of the cost to replace a concrete driveway, ice melt is very cheap.