Examples of the Use of Non-Invasive Techniques for the Evaluation of Stone Decay in Portugal

Abstract

Today experts agree that precise damage diagnosis is the key to comprehensive characterization, interpretation, rating and prediction of stone damage. It provides vital information for monument conservation and sustainable preservation. Better understanding of the stones used in monuments and the factors, processes and characteristics involved in stone decay is therefore essential to the sustainable preservation of cultural heritage. A frequent and major obstacle to studying stone decay in monuments is the impossibility of touching or obtaining samples for study in the laboratory or even in-situ. The aim of this paper is to present the results of three non-invasive geophysical (3-D electrical resistivity and seismic refraction) and geochemical (soluble salts typology and distribution) techniques, that were used to diagnose stone damage in case studies involving Portuguese cultural heritage. Different techniques were applied based on decay typology or observed phenomena.