Definitions for "Pozzolana"
Keywords:  pozzuoli, volcanic, ash, roman, mortar
Volcanic ashes from Pozzuoli, in Italy, used in the manufacture of a kind of mortar which hardens under water.
volcanic dust mixed with lime and used in mortar by the Romans
the volcanic ash of central Italy, named after the region where its properties were first recognized and, when mixed with lime, the material which gave Roman concrete its strength and ability to harden in water