What process involves the chemical reaction between cement and water that causes concrete to harden?

The chemical reaction that occurs between cement and water, known as hydration, is critical in the process of concrete hardening. During hydration, various compounds in the cement interact with water to form new products that provide strength and durability to the concrete. This process generates heat and leads to the setting and hardening of the mixture over time, allowing it to achieve its structural integrity.

Hydration is essential because it determines the physical properties of the hardened concrete, including its compressive strength and durability. Adequate curing conditions must be maintained to ensure complete hydration, which is vital for the performance of the concrete. By understanding this process, one can effectively evaluate the quality and acceptance of concrete during plant inspections.

The other options, while related to the behavior of concrete in some contexts, do not accurately describe the specific chemical reaction responsible for hardening. Evaporation pertains to the loss of water from the surface, which can negatively affect hydration if not controlled. Solidification generally refers to the phase change from liquid to solid without indicating the specific chemical processes involved. Compaction is a mechanical process that densifies the concrete but does not involve the chemical transformation that occurs during hydration.