Gibbons, P. Pozzolans for lime mortars. 1997

HOME DIRECTORY ARTICLES BOOKSHOP WHAT S ON Pozzolans for Lime Mortars Pat Gibbons Materials which enable lime mortars to set more rapidly include ash and brick dust. Known as pozzolans after the volcanic additives used by the Romans, these materials... More

HOME DIRECTORY ARTICLES BOOKSHOP WHAT S ON Pozzolans for Lime Mortars Pat Gibbons Materials which enable lime mortars to set more rapidly include ash and brick dust. Known as pozzolans after the volcanic additives used by the Romans, these materials are widely found in the lime mortars used in old buildings and monuments. Where conservation work is required, new mortars ought to match these mortars, not only to ensure continuity with the past, but also to ensure that the new work is both visually and physically compatible with the old. It is therefore important that we know more about the performance of these additives. A simple everyday definition of pozzolan could be a finely powdered material which can be added to lime mortar (or to Portland cement mortar) to increase durability and, in the case of lime mortars, to provide a positive set . A more formal definition is given by ASTM(1) C618 as a siliceous or siliceous and aluminous material which, in itself, Less