How long should a freshly poured concrete surface exposed to air be cured?

Curing freshly poured concrete is a critical step that ensures the proper hydration of the cement, which is essential for achieving the desired strength and durability of the concrete. When concrete is cured properly, it can help prevent issues such as cracking, shrinkage, and surface scaling.

Typically, the general rule for curing concrete exposed to air is to maintain it in a moist condition for at least 7 days after pouring. This allows the concrete to hydrate effectively and achieve its maximum potential strength. During this period, the chemical reaction between the water and cement continues, solidifying the mixture and integrating the aggregates.

Although shorter curing times may be sufficient for some specific mixes or under certain conditions, adhering to the 7-day guideline is a widely accepted practice in many guidelines, including those from the American Concrete Institute. This recommendation provides a buffer to ensure that the concrete can withstand environmental factors like wind, heat, and low humidity that may accelerate moisture loss. Thus, for optimal results in most situations, a curing period of 7 days is essential.