Adsorption in the context of cement and concrete refers to the process where molecules from a liquid or gas phase adhere to the surface of solid materials used within the concrete mix, such as cement particles, aggregates, or additives. This can significantly influence the hydration reactions, setting, and curing of cement. Adsorption occurs due to physical forces (physisorption) or chemical bonds (chemisorption), with varying implications on the material properties depending on the nature of the adsorbate and the substrate.