Final answer:
Concrete should be kept moist for a minimum of 7 days after finishing for proper curing, with the process sometimes extending to 28 days for certain applications to ensure that the concrete achieves its designed strength and durability.
Step-by-step explanation:
After finishing concrete, it should be kept moist for at least 7 days. This process is known as curing and is critical for the concrete to achieve its designed strength and durability.
The curing period can extend up to 28 days for some types of concrete or for structures which will bear heavy loads. During the initial stages of curing, it's imperative to ensure that the concrete does not dry out, as this can lead to cracking and weaken the structure.
The purpose of keeping concrete moist during the curing process is to allow the cement particles to continue to hydrate, which is necessary for the chemical reaction that causes the concrete to harden and gain strength. Effective curing methods include spraying or misting the concrete with water, covering the concrete with wet burlap or a curing blanket, or using a curing compound that seals in moisture.