Concrete does not dry — it cures. The hardening is a chemical reaction, not evaporation:

• Tricalcium silicate in cement reacts with water to form C-S-H gel and calcium hydroxide. This reaction produces heat (exothermic)
• C-S-H gel is the glue — a nanoscale matrix of calcium, silicon, oxygen, and water that grows into interlocking fibers
• Full curing takes about 28 days to reach design strength, though the reaction continues for years
• Adding too much water weakens concrete because excess water creates pores. The water-to-cement ratio is the single most critical factor in concrete strength.