Stone masonry arches may be found in a large number of constructions that are mainly historic buildings: housing, places of worship, footways, bridges, aqueducts and waterways, among others. They are all of great functional and architectural importance.

Although relatively solid structures, time has taught us that environmental conditions, as well as their load history, use and possible accidents can lead to their collapse, all of which entails a risk of losing a large amount of our architectural and cultural heritage.

Within the framework of this Doctoral Thesis, a strengthening system for the

rehabilitation of stone arches is investigated, which provides an alternative to the usual reinforcement methods. An effort is made to contribute to the knowledge base on the behaviour of stone arches and the effectiveness of a strengthening system based on basalt fibres embedded in an inorganic matrix (cement‐free mortar modified with polymers) known as Basalt Textile‐Reinforced Mortar (BTRM). Its use is justified by the physical‐chemical characteristics of the materials that constitute the reinforcement (resistance to high temperatures, permeability to water vapour, flexibility, etc.) that make this solution a compatible technology that is easily applied to masonry works and, particularly, to those with a complex geometry (arches, vaults, etc.). The competitive cost of this system in comparison with the costs of current reinforcement methods is also worth mentioning.

The research work was designed with an integral focus on this reinforcement solution and its application to stone masonry (and especially to ashlar masonry). The first stage involved mineralogical and mechanical tests to characterize the materials that constitute the masonry, in terms of each constituent material and the compound as a whole. In order to do so, twenty four half‐scale prismatic specimens were built, changing the composition of the material (stone and mortar) and its layout. The second stage, an in‐depth study of the proposed reinforcement system, involved physical‐chemical tests on the basalt textile, the inorganic matrices and the compound textile‐matrix. In the third stage, twelve arches were tested by means of displacement control up to the point of collapse. These arches were built and strengthened according to different criteria: two building techniques (dry ashlar masonry with and without mortar between the voussoirs) and four different types of strengthening systems (without BTRM, strengthened on the intrados, on the extrados and on both). Finally, different calculation methods were used to conduct an analytical evaluation of the

reinforcement system and its effects.

The experimental results obtained in this Doctoral Thesis demonstrate good physical‐chemical compatibility between the BTRM reinforcement system and the corresponding stone masonry substrate and validate its mechanical effectiveness for the reinforcement of arched structures.