Noun
pozzolan (plural pozzolans)
Any material which, when combined with calcium hydroxide, exhibits cementitious properties; often used as an extender with Portland cements.
Common stabilization materials include pozzolan cement grout and polyurethane. Source: Internet
There is evidence that the Minoans of Crete used crushed potshards as an artificial pozzolan for hydraulic cement. Source: Internet
They are similar to pozzolan lime cements in their properties. Source: Internet