Influence of thick mortar joints on the early and late mechanical behaviour of Byzantine constructions

Stack-bond prisms built with joints 40mm thick, reproducing the type of masonry used for the Byzantine Basilica of St. Vitale in Ravenna (Vth Cent. AD) were tested under compression by the authors at different time of curing (28, 60, 90, 180, 365 days). The results show a high influence of the joint thickness on the mechanical behaviour of the masonry, particularly at an early age. The use of thick joints in brick and stone masonry seems to prove that the Byzantine masonry was an intelligent material highly suitable to react towards possible stresses occurring during the structure long life-span, e.g. allowing for large soil settlements without the development of important crack patterns.