The principle of curing is to keep a small amount of water for 7 days-14 days. After concrete pouring, it should be kept at about 20 degrees according to the season and temperature. After a few hours, water the concrete regularly and keep it moist, so that the cement has enough water during the hardening process. If the curing is not good, it will greatly affect the strength of concrete. But earthwork can be backfilled after 7 days.