What is the primary function of admixtures in concrete?

The primary function of admixtures in concrete is to enhance performance characteristics. Admixtures are materials added to the concrete mix to modify its properties, which can include workability, strength, setting time, and durability. For example, water-reducing admixtures can improve the workability of concrete without increasing water content, leading to higher strength and lower permeability. Other admixtures can accelerate setting or hardening times, provide resistance to freezing and thawing, or increase resistance to chemical attacks.

While additives can influence color or aesthetic aspects and may have cost implications, the main purpose remains to optimize and improve the overall performance of the concrete in various applications. This is crucial in achieving desired structural qualities and meeting specific environmental challenges.