ACI 212.3R-10 Report on Chemical Admixtures for Concrete

ACI 212.3R-10 Report on Chemical Admixtures for Concrete. 2.1—Definitions ACI provides a comprehensive list of definitions through an online resource, “ACI Concrete Terminology,” http://terminology.concrete.org. Definitions provided herein complement that resource. admixture—a material other than water, aggregates, cementitious materials, and fiber reinforcement, used as an ingredient of a cementitious mixture to modify its freshly mixed, setting, or hardened properties and that is added to the batch before or during its mixing. admixture, accelerating—an admixture that causes an increase in the rate of hydration of the hydraulic cement and thus shortens the time of setting, increases the rate of strength development, or both. admixture, air-entraining—an admixture that causes the development of a system of microscopic air bubbles in concrete, mortar, or cement paste during mixing, usually to increase its workability and resistance to freezing and thawing. admixture, retarding—an admixture that causes a decrease in the rate of hydration of the hydraulic cement and lengthens the time of setting. admixture, water-reducing—an admixture that either increases slump of a fresh cementitious mixture without increasing water content or maintains slump with a reduced amount of water, the effect being due to factors other than air entrainment. 3.3—Specifications for admixtures The following standard specifications cover the admixture types that make up the bulk of products covered in this report: • Air-entraining admixtures: ASTM C260 and AASHTO M154; • Water-reducing and set-controlling admixtures: ASTM C494/C494M and AASHTO M194; • Calcium chloride: ASTM D98 and AASHTO M144; • Admixtures for use in producing flowing concrete: ASTM C1017/C1017M; and • Pigments for integrally colored concrete: ASTM C979. ASTM recently approved a Type S (specialty admixture) designation that includes admixtures not covered by other ASTM standards. The results obtained from tests done in accordance with ASTM C494/C494M will ensure that these products give values that closely matched those of the untreated reference concrete and therefore meet all the requirements of the standard.ACI 212.3R pdf download.