What is a natural pozzolan?

In This Section

Other Sources for Answers

Search other resources on the ACI website for answers to technical questions

Technical Questions

ACI Committees, Membership, and Staff have answered common questions on a variety of concrete related topics.



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