Hierarchy classification:

1. top of the aat hierarchies
2. Materials Facet
3. Materials (hierarchy name)
4. materials (substances)
5. [materials by composition]
6. inorganic material
7. clay
8. [clay by composition or origin]

Additional parents:

1. top of the aat hierarchies
2. Materials Facet
3. Materials
4. materials
5. materials by function
6. additive

Narrower term/s

• metakaolin

Anotations

Scope note:

A rosy red volcanic clay that has been used as a pigment and a component in cement; pozzolana itself possesses little or no cementitious value, but in finely divided form and in the presence of moisture, it will chemically react with calcium hydroxide at ordinary temperatures to form compounds possessing cementitious properties. Pozzolana is mined at Pozzuoli near Naples, Italy. It has been used since ancient times by the Romans.