Bowing of marble slabs: an integrated measurement system to monitor and predict the façade weathering

the bowing of marble slabs, more and more frequent for the new building constructions, is bonnected to the rock weathering. The aim of this work is to suggest a methodology to monitor and predict the bowing of cladding marble slabs. This has been possible by means of in situ and laboratory tests. The evaluation in situ of the decay state has been performed by means of non-destructive tests such as bowing, water absorption and ultrasonic pulse velocity (UPV) measurements directly related to the physical-mechanical properties of the stone. In laboratory, the non-destructive measurements together with a destructive mechanical test have been performed on specimens in natural conditions, on specimens taken from building façade and on specimens subjected to different number of cycles of a Lab - Bow test reproducing on the stone specimens placed on wet sand, the effects of climatic changes (main cause of bowing for natural stones).