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What is a natural pozzolan?

Q. What is a natural pozzolan?


A. A natural pozzolan is a raw or calcined pozzolan that is found in natural deposits. A material is referred to as “calcined” when it has been heated below the temperature of fusion to alter its composition or physical state. A raw pozzolan is a natural material that has pozzolanic properties, such as volcanic tuffs or pumicites, opaline cherts and shales, clays, and diatomaceous earths.


References: SP-1(02)E3-13SP-221; ACI 232.1R-12

Topics in Concrete: Pozzolan; Cementitious MaterialMaterials in ConcreteConcrete Fundamentals

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