Popouts refers to conical fractures of the concrete surface caused by ice expansion inside porous coarse aggregates (chert, coal, etc) located just below concrete surface. Air entrainment provides freeze thaw protection from the cement paste but not the large coarse aggregates. Popouts are distinguished from mortar flaking by the presence of fractured aggregate in the popout. Some causes for popouts might be: local aggregate sources contain soft, porous material, concrete in a fully saturated condition, concrete hasn’t achieved durability potential due to inadequate curing. Below are some ways to reduce the likelihood of such problems:
-Ensure no porous material is mixed with aggregate
-Ensure proper curing and protection practices to ensure full durability and eliminate poor curing as a possible cause.
-Consider use of sealers to limit the inflow moisture into the concrete