Reconstruction of a stone masonry building with a new technology of fair-face double leaf masonry wall

Fair-face rubblestone masonry is a very common masonry typology in old buildings and it characterizes the architecture of many hamlets in Italy and abroad. Past earthquakes have shown its high vulnerability, especially when built with multiple-leaf masonry walls, which fail by leaf separation and/or the disintegration of individual stones under out-of-plane seismic actions. The severe damage caused by earthquakes to this type of buildings highlights the need of retrofitting them. Due to the difficulties of achieving a significant capacity enhancement, demolition and reconstruction often results the preferable option. To this purpose, appropriate technologies are needed, which are sustainable, durable, easy to realize and guarantee the seismic safety and energy efficiency typical of new buildings, safeguarding, at the same time, the architectural asset of pre-existing urban context. A new technology was developed to meet all these needs, consisting of a double leaf masonry wall: the internal leaf is made of reinforced clay masonry and the external one is made with fair-face stone masonry. The two leaves are connected through a pre-cured glass fibre reinforced polymer mesh. The effectiveness of this new technology in providing the wall with a monolithic behaviour was verified by means of shake table tests (topic of a dedicated paper in the present Conference). This paper presents the field application of the proposed innovative technology to a two-storey building located in a high seismic hazard site, which underwent reconstruction and seismic/energetic upgrade. The design phases are described, considering global and local analyses carried out to check that monolithic behaviour is ensured under out-of-plane seismic actions. The case study shows the effectiveness and the high safety level of the new technology developed for fair-face rubblestone masonry in earthquake prone areas.