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The boeing potential of eleven varieties of Portuguese limestones were studied. Only one variety (Valverde) show evident bowing, reaching values around 9 mm/m after 91 cycles. This variety is also the only one showing hydric dilatation with values around 0.26 mm/m after 24 hours. Residual strain happens only in wet conditions, with values around 0.25 mm/m.

Petrographic observations of this variety highlight the presence of disturbed areas with parallel microstylolites. The microstylolites are of an opaque material, probably accumulations of organic material and clays. Both water and heat may cause the opening and offsetting of the microstylolites causing irreversible deformation.

Further studies are necessary to fully explain this bowing behavior. Meanwhile, this stone should not be used as a cladding material in a humid and warm environment, where bowing behavior can occur more easily.