Mortar flaking refers to dislodging of small distinct delaminations of concrete overtop of the coarse aggregate particles (exterior concrete). Typically occurs in exterior concrete that was not properly cured during the first 7-28 days. Mortar directly on top of the aggregate was allowed to dry out and not properly cured. Excess water present in the concrete is forced to travel around aggregate particles as it rises to the surface and the mortar directly above fails to develop appropriate strength. Some causes for Mortar Flaking might be: concrete placed during periods of rapid surface drying, concrete not cured at all, curing compound applied too late after concrete placement (i.e. the following day). Below are some ways to reduce the likelihood of such problems:

-Proper curing procedures should eliminate the problem completely

-If rapid surface drying occurs use evaporation retardants or plastic sheeting cover between finishing

-Wet curing methods or fog spraying systems can help during severe hot or dry curing periods