Admixture: A chemical or mineral additive incorporated into concrete or mortar to modify performance characteristics.

Admixture is a commonly used term in the construction industry. Admixture refers to a chemical or mineral ingredient added to concrete or mortar, other than cement, aggregate, or water, to alter properties such as workability, setting time, strength, or durability. Common types include water‑reducers, superplasticizers, accelerators, retarders, air‑entraining agents, and silica fume or fly‑ash mineral additives. By adjusting mix performance, admixtures enable cold-weather placement, high-strength columns, reduced permeability, or extended pumpability in high-rise projects. Proper dosage and compatibility are essential; overdosing can cause flash set, segregation, or long‑term strength loss.

Fun Fact: Ancient Roman concrete utilized volcanic ash as a natural pozzolan admixture, lending its marine structures remarkable durability that still impresses engineers today.