Curing compound
A liquid sprayed on fresh concrete that forms a temporary film to slow moisture loss. It is the most practical curing method for large flatwork and pavement.
What does curing compound mean?
Compounds come clear, dyed for visible coverage, or white-pigmented to reflect heat on pavements. They only work if applied at the rated coverage rate, since a thin application does not form a continuous film at all. Because they are designed to degrade over time, they are not sealers, and residue left on a slab scheduled for coatings or flooring is a common bond-failure cause.
In practice
On a big pour, one worker walking behind the finishers with a sprayer is doing more for the slab's surface durability than anyone else on the crew.