Existing buildings are often in need of strengthening interventions, and several technical solutions have been recently developed for this purpose. Among them, the use of textile-reinforced mortar (TRM) composites has gained consensus as a technically viable and economically convenient option. Moreover, TRM has the potential to be employed as a reversible and sustainable strengthening technique for masonry buildings. In this context, the present paper aims to investigate the mechanical properties of TRM systems consisting of sustainable phases, such as lime-based matrices and natural fabrics produced by waiving fibers obtained from plants, such as Jute or Flax. This class composite system can be referred to as natural TRM and is denoted by the acronym NTRM. The present study moves from the geometric and mechanical characterisation of fibres and fabrics and, after having also investigated the properties of the mortar, it reports the results of tensile tests carried out on specimens of the NTRM systems under consideration, with the main aim of providing the empirical bases of the relationships between the geometric and physical properties of the constituents and the resulting mechanical response of the composite system. The obtained results show that the considered Flax-TRM system has an apparent composite behavior, as its response to tension is clearly characterised by the well-known three stages corresponding to the elastic response, the formation of cracks, and the reinforcement response up to rupture. Conversely, the Jute-TRM system needs to be further improved in terms of balance between the properties of the matrix and the internal reinforcement. Further studies will be devoted to this specific aspect and, more generally, to investigating the relationships between constituents’ properties and the NTRM behavior.

The paper analyses the problem of assessing the seismic capacity of walls subjected to seismic loading, with particular emphasis to out‐of‐plane loads, before and after reinforcement. A new retrofitting method, consisting in the use of high strength steel strands embedded in the mortar bed joints was studied. The proposed method allows to preserve the fair-faced aspect of the masonry, while improving the out-of-plane capacity of the building’s wall panels perpendicular to the direction of the seismic action (face-loaded walls). An experimental investigation using full-scale masonry specimens was carried out in an attempt to assess the walls’ structural response when these are subject to out-of-plane loads. Test results demonstrated that it is possible to increase the out-of-plane capacity of the walls with the proposed method. However, it is shown that the out-of-plane capacity of face-loaded walls is sensitive to several parameters, which are usually affected by strong uncertainty when assessing an existing building, namely the boundary conditions, the tensile strength of the mortar and the wall-to-wall connections.

The sequence of major earthquakes that has affected Italy in recent decades has required the use of materials and innovative techniques for the security of damaged buildings. Fibre Reinforced Polymer (FRP) represents a novelty in the field of seismic improvement techniques applicable also to historical masonry buildings. The use of composite materials can respect the conservation principles of the monumental buildings. This study describes the effectiveness of the seismic improvement techniques carried out by means of FRP in the Spoleto cathedral (Italy) after the 1997 Umbria-Marche earthquake. The strengthening work concerned the making safe of damaged vault structures by means of gluing fibreglass bands (GFRP). After 20 years, during the 2016 Amatrice-Norcia earthquake, near Spoleto, the cathedral reinforced with the GFRP bands has not suffered any damage demonstrating the effectiveness of the seismic strengthening techniques.