The Source Materials for Lime Production in the Monte Pisano Area (NW Tuscany, Italy)

Abstract

In the Monte Pisano area (north-western Tuscany, Italy) several limestones outcrop and some of them are carbonate-rich rocks that were used for air-hardening lime or hydraulic lime production. Since Roman times, carbonate rocks outcropping in the Monte Pisano area have been used for that purpose. Monte Pisano is a mountainous system of modest size that is part of the Tuscan Apennine, located in the north-western part of Tuscany, and it separates the two cities of Pisa and Lucca. As an obvious consequence of the presence of good source rocks useful for the production of lime, in the surroundings of Monte Pisano there was a great use of carbonate rocks for the production of aerial lime and hydraulic lime. In fact, the monumental buildings in the Middle Ages were built making extensive use of binding materials obtained by firing rocks belonging to formations of the Tuscan metamorphic sequence: the Monte Pisano marble and the Selciferous Limestone. Several famous monuments in Pisa’s Miracle Square and in Lucca’s historical centre were built by using air-hardening lime and hydraulic lime obtained by firing these rocks. The aim of this work is to characterize samples from the Monte Pisano quarries, where the aforementioned carbonate-rich stones were quarried to produce air-hardening lime and hydraulic lime, by mean of chemical, mineralogical and petrographic studies and by determining their physical and mechanical properties. These same properties will also be determined on handmade mortar samples made up of self-produced binders and normalised sand to evaluate the best uses, and the optimum time and temperature of stone firing.