Saturday, October 30, 2004


Also spelled �pozzuolana�, or �pozzolan� hydraulic cement discovered by the Romans and still used in some countries, made by grinding pozzolana (a type of slag that may be either natural - i.e., volcanic - or artificial, from a blast furnace) with powdered hydrated lime. Roman engineers used two parts by weight of pozzolana mixed with one part of lime to give strength to mortar and concrete in bridges and other masonry