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What is a pozzolan?

Q. What is a pozzolan?


A. A pozzolan is a siliceous or siliceous and aluminous material that in itself possesses little or no cementitious value but will, in finely divided form and in the presence of moisture, chemically react with calcium hydroxide at ordinary temperatures to form compounds having cementitious properties. It is therefore classified as cementitious material. There are both natural (ACI 232.1R) and artificial (fly ash, ACI 232.2R, and silica fume, ACI 234R) pozzolans. Descriptions of various kinds of pozzolans and specifications for them are given in ASTM C618 and ASTM C1240.


References: SP-1(02); E3-13 ; SP-221; ACI CT-23; ACI 232.1R-12; ACI 232.2R-03; ACI 234R-06; ASTM C618; ASTM C1240

Topics in Concrete: Pozzolan; Cementitious Material; Materials in Concrete; Concrete Fundamentals

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