what are the admixtures needed for pervious concrete
Chemical admixtures are used in pervious concrete to obtain special properties, as in conventional concrete. Because of the rapid setting time associated with pervious concrete, retarders or hydration-stabilizing admixtures are commonly used. Use of chemical admixtures should closely follow manufacturerâs recommendations. Air-entraining admixtures can reduce freeze-thaw damage in pervious concrete, and are used where freeze-thaw is a concern. ASTM C 494 governs chemical admixtures, and ASTM C 260 governs air-entraining admixtures.