Rehabilitation and consolidation of high-value "camorcanna" vaults with FRP.

This paper deals with the topic of the mechanical compatibility of interventions carried out with fibre-reinforced plastic (FRP) on light vaults (camorcanna) made up of plaster and reed laths hanging from wooden centrings that feature stucco decorations and pictorial cycles of high artistic value. A series of experimental tests and numerical analyses showed that such interventions must be considered with extreme caution as concerns the preservation of high-value intradoses. Practical criteria for suitable rehabilitation actions are also provided. As a matter of fact the research results showed that an extensive use of FRP at the extrados brought about both unwanted mechanical effects and—under the same conditions—the development of tensile stress at the intrados—and consequently cracking—on the paintings and decorations, while the stress was not there before consolidation.