Concrete typically takes about 24 to 48 hours to dry enough on the surface to be walked on or to handle light foot traffic

. However, this initial drying does not mean the concrete has reached its full strength or is fully cured. Full curing of concrete, which is the process where it gains its maximum strength and durability, generally takes about 28 days

. During this curing period, the concrete undergoes chemical reactions that harden it internally. After 7 days, concrete usually reaches around 65-70% of its full strength, and by 28 days, it is considered fully cured and ready for heavy loads or construction work on top of it

. The drying and curing processes are different: drying refers to the evaporation of moisture from the concrete surface, while curing is the chemical hydration process that strengthens the concrete

. Several factors influence drying and curing times, including:

• Ambient temperature: Higher temperatures speed up curing, while lower temperatures slow it down

• Humidity and moisture levels: Proper moisture retention is critical for curing; drying too quickly or losing moisture can weaken the concrete

• Concrete mix composition and water-to-cement ratio: More water increases drying time; the right balance is essential for proper curing

• Thickness of the concrete slab: Thicker slabs take longer to dry and cure fully

In summary:

• 24 to 48 hours : Surface dry and set enough for walking.
• 7 days : About 65-70% cured, can support moderate loads.
• 28 days : Fully cured, maximum strength achieved.

For best results, concrete should be kept moist during curing to prevent premature drying and cracking

. Drying beyond 28 days can continue as excess water evaporates, especially in thicker slabs

. This timeline applies to typical concrete used in sidewalks, slabs, and foundations but may vary with special mixes or environmental conditions.