Laser speckle correlation for monitoring building stone efflorescences

Salt weathering affects rocks, building stones, mortars, bricks and paintings. The aim of this paper is to present a digital speckle system that allows to study efflorescence mechanisms on stone samples and, at the same time, to measure the damage due to salt crystals accumulated inside the material. Some tests have been performed on quarry samples with characteristics similar to those of some ancient artifacts of L'Aquila, submitted to accelerated salt crystallisation (NaCl) cycles; preliminary experiments have been effected.