Light vaults with frescoes or stuccoes strengthened by gfrp, the role of the reinforcement on intrados strains: first experimental data

In many historical buildings built between the 16th and 19th centuries, light vaults are present made by wooden structures and mats of reeds and plaster carrying frescoes or stuccoes of architectural and historical value on the lower surface. Some of these structures today are in a precarious state of conservation, and a wide program of rehabilitation has started, especially with the use of glass fiber-reinforced polymer (GFRP) bandages on the upper surface. This article experimentally evaluates the effect that GFRP extrados bandages may have on the mechanical behavior of this system. In particular, the main issue is to evaluate how GFRP extrados reinforcement affects the intrados surface strains of the fresco or stucco plaster. Results show that GFRP reinforcement changes the mechanical behavior of the original system. In particular, under a particular load condition, intrados plaster surface — and thus frescoes or stuccoes — may deform more in the reinforced case than in the original case. Thus, looking forward to have more experimental results, GFRP strengthening should be carefully applied to this historic system to avoid frescoes and stuccoes on the intrados surface that could more easily crack for loads that were carried with no fissures before GFRP strengthening.