The Groin Vaults of St. John Hospital in Jerusalem: An Experimental Analysis on a Scale Model

The St. John Hospital is part of a larger complex of buildings known as the Hospitallers Quarter, located south of the Holy Sepulchre in Jerusalem. At present, the hospital looks like an irregular volume both in height and in plan; it is covered by ten groin vaults resting on very stocky pillars. Each vault is formed by intersecting double curvature surfaces. In order to verify the effectiveness of continuous carbon fiber reinforced polymer sheets reinforcement, bonded at the extrados of vaults, laboratory tests were carried out on a 1:5 scale model, built with materials and construction techniques similar to those of the real building. Experimental tests were performed on the unstrengthened and strengthened vault. The experimental results shown that the strengthening system is able to increase the collapse load of the vault, without substantial variation of the initial stiffness.