Linearno toplotno širenje građevinskog kamena poreklom iz plutonskih magmatskih kompleksa Eksterne vardarske zone Srbije

Abstract

Thermal properties of the building stone used for cladding and flooring, especially in exteriors, are significant for durability and lifespan of buildings' surfaces covered with it, but also their aesthetic properties in the sense of integrity. Linear thermal expansion of natural stone units is determined in laboratory examinations, aiming to provide the value of yield between the units as free space for their dilatation and contraction upon temperature oscillations. Where this space is not provided, diurnal changes, especially temperature increase, create stone expansion and tension which can lead to deformations of stone units and mar units' and covered surfaces' integrity and aesthetics. Data on linear thermal expansion values of natural stone, especially from Serbia, are very rare in the literature, so our aim is to contribute to this type of knowledge. Examination of thermal dilatation of stone originating from eight plutonic massifs in External Vardar zone of Serbia has shown that the values are very small, parts of millimetres, and lower than those of the similar rock types originating from China, Brazil and Eastern Serbia. A clear grouping of the values of thermal expansion of the stone according to the genetic groups to which the plutons belong to can be observed. Mineral composition, grain size and presence of metallic minerals in samples have shown no clear influence on thermal dilatation values, but fabric inhomogeneity appears to cause the increase of these values.