ZMIANY MIKROSTRUKTURALNE WAPIENI JURAJSKICH, UŻYTYCH W WYBRANYCH OBIEKTACH ZABYTKOWYCH, JAKO EFEKT ANTROPOGENICZNYCH ZANIECZYSZCZEŃ ATMOSFERY

Cracow is a town of exceptional historical significance. It contains about 3 500 historical buildings, chiefly of a sacral nature, constructed of assorted types of material, including limestone. Owing to the considerable emission of pollutants, both gas and dust, Cracow witnesses a rapid rate of the damage suffered by its valuable objects. Microstructural studies on limestone from houses in 17 and 18 Kanoniczna Street, the church of the Holy Virgin Mary and the Decjusz Villa made it possible to define properly the structure and texture of the stone, its mineral composition and porosity. Furthermore, they permitted an assessment of the susceptibility of limestone to the tempo and nature of destruction leading to the appearance of gaps. One of the methods applied for the reconstruction of such gaps is the use of mineral masses which correspond to the conserved stone not only as regards its outer appearance but also its physical and mechanical properties. Such masses are safe for the health of the users, reversible, and possess appropriate functional qualities. The conservation market offers a special Reno SUPERBET mortar, devised by a group of scientists from the Mining and Metallurgical Engineering Academy in Cracow. This mortar consists of several types of mineral masses employed for supplementing gaps in various types of limestone and sandstone.