Which chemical ice melters harm or even discolour concrete?
Some ice melters containing the additives of ammonium nitrate or ammonium sulphate will rapidly disintegrate concrete and therefore should not be used. Discolouring, however, is primarily caused by calcium chloride. It does this by accelerating the hydration process, but yet having a retarding effect on the hydration of the ferrite compound in Portland cement. This ferrite phase normally would become lighter with hydration. However in the presence of calcium chloride, the retarded un-hydrated ferrite phase remains dark. Concrete scaling Concrete scaling and flaking is the loss of surface mortar. It is primarily a physical action caused by hydraulic pressure from water freezing within the concrete, and not by a chemical corrosive action. It is for this reason that it is necessary to extend the thaw/freeze cycle as long as possible. It is best NOT to use calcium chloride based ice melters, as they have the shortest thaw/freeze cycle. Concrete spalling Spalling is a surface defect that is
