Sandstone decay: from historical buildings to laboratory tests

Sandstone is a sedimentary rock whose composition is determined by the depositional environment. The large family of sandstone covers, therefore, stones showing a great variability in grains, porosity, cement or matrix, compactness, chemical composition etc., some times this variability can be found in the same quarry too: in historical buildings often can be observed stones coming from the same quarry showing a different decay behaviour. This study is focused on some Italian sandstones with the goal of assessing the main intrinsic factors connecting with their durability and of optimizing the test methodologies for the decay evaluation. The results of durability tests on sandstones with different petrographic and mineralogical properties have been analysed. Moreover all the durability tests have been performed following the EN standards methodology. From the results some indication have been obtaining concerning: - the effectiveness of the durability tests to reproduce the sandstone decay; - the effectiveness of the evaluation methodology to assess the induced decay.