Author
G. DE CASA and G. SAPPA University “La Sapienza”, Rome.

Abstract
The long history of this widely used building stone and its architectural uses in historic buildings are briefly described. The growing need for technical intervention for conservation and rehabilitation requires greater knowledge of its characteristics. The results of petrographic .studies, and mechanical and simulated weathering tests are given, including freeze/thaw, saturated salt solutions and cycles of wetting and drying.