Moist curing (wet curing)
Keeping concrete continuously wet with water, wet burlap, or covered plastic sheeting during the early curing period. It is the most effective curing method available.
What does moist curing (wet curing) mean?
Continuous moisture allows hydration to proceed at full rate and produces the densest, most durable surface. The critical word is continuous: intermittent sprinkling that lets the surface dry between wettings cycles the concrete and can cause crazing. Plastic sheeting laid directly on a fresh slab can cause blotchy discoloration, so it is generally used over wet burlap rather than alone on architectural work.
In practice
Wet burlap under plastic for a week is old-fashioned, inconvenient, and still the best result money can buy on a slab that matters.