___ are materials added to a concrete mix to achieve specific properties.

___ are materials added to a concrete mix to achieve specific properties.

• A. Admixtures
• B. Reinforcements
• C. Finishes
• D. Aggregates

Answer: (A)

Admixtures are materials added to a concrete mix to achieve specific properties. They’re used in small amounts to modify things like workability, setting time, durability, and resistance to weather or water. For example, plasticizers or superplasticizers improve flow without adding extra water, accelerators speed up hardening in cold weather, retarders slow it in hot weather, and air-entraining agents help withstand freeze–thaw cycles. In contrast, reinforcements (like steel bars) provide strength under load, finishes are applied after mixing and curing to change appearance or surface qualities, and aggregates (sand and gravel) form the bulk of the concrete and influence strength and volume but aren’t added to achieve specific properties through chemical modification.

Admixtures are materials added to a concrete mix to achieve specific properties. They’re used in small amounts to modify things like workability, setting time, durability, and resistance to weather or water. For example, plasticizers or superplasticizers improve flow without adding extra water, accelerators speed up hardening in cold weather, retarders slow it in hot weather, and air-entraining agents help withstand freeze–thaw cycles. In contrast, reinforcements (like steel bars) provide strength under load, finishes are applied after mixing and curing to change appearance or surface qualities, and aggregates (sand and gravel) form the bulk of the concrete and influence strength and volume but aren’t added to achieve specific properties through chemical modification.