In the context of cement and concrete, “surface area” primarily refers to the specific surface area of the cement particles, which is a critical factor influencing the hydration, setting, and hardening processes. The surface area of cement particles determines the rate at which water can hydrate the cement, impacting both the early and long-term strength development of concrete. A higher surface area generally leads to faster hydration reactions, as more particle surface is available for water–cement interaction. This is particularly important under severe environmental conditions, where the rate of hydration can be altered by temperature extremes, moisture availability, and chemical exposures. In conditions such as cold weather, a higher surface area can compensate for the slower hydration reaction rates, aiding in maintaining setting times and strength development schedules (Powers 1968).