Seismic Strengthening of Masonry Vaults with Abutments Using Textile-Reinforced Mortar

Innovative materials and technologies have been developed to limit the effects of earthquakes on structures, and the use of composite materials has been shown to be effective in existing buildings. In view of this background, experimental tests can provide a contribution to the interpretation of available strengthening interventions. The results of experiments with an innovative strengthening system are presented herein. The strengthening technique used is based on a textile-reinforced mortar (TRM) system coupled with traditional strengthening approaches, and was applied to a type of full-scale masonry vault that is typically found in the roofs of religious buildings. The experiments consisted of several shaking table tests, both before and after the application of the strengthening system. The seismic behavior of the vault after strengthening was significantly improved. The instrumental response of the vault started to change before the initial visible damage, which only occurred when the peak ground acceleration (PGA) was almost doubled. The seismic capacity of the unreinforced vault was more than doubled when the strengthening was applied, with the vulnerability moving from the curved element to the masonry abutments. As a consequence, additional interventions should focus on lateral abutments. There was no debonding between the TRM and the masonry substrate, and the strengthening strategy (combination of innovative and traditional approaches) was effective in preventing the failure of the vault.