Textile-Reinforced Mortar (TRM) is a modern and compatible strengthening strategy for existing masonry, which consists in plastering the walls by means of mortar layers with embedded grids or textiles made of long fibers. TRM can be very useful for the reduction of the seismic vulnerability of masonry buildings, since the fiber-based reinforcement, carrying high tensile stresses, opposes the widening of cracks and provides “pseudo-ductility” to the masonry. The increasing number of available studies on the subject testifies to its relevance but also the lack of a standardized or well-establish approach to quantify the benefits of these systems on the performance of masonry. The present review is aimed at providing a broad overview of how the study of TRM-strengthened masonry elements has been addressed in the literature. In particular, the main features of the different experimental tests are compared, dealing with both in-plane and out-of-plane behavior. Moreover, the different design methods and numerical modeling strategies are presented and discussed.

The research addressed in the paper is aimed at calibrating a numerical model developed by using a free open-source finite-element code for the assessment of the structural performances of historical masonry buildings strengthened using the textile-reinforced mortar (TRM) technique. TRM is a near-surface-mounted system, which couples inorganic matrices with fiber-based textile or meshes. The main purpose is to develop a multiple-level numerical approach, starting with the detailed modeling of components and interfaces, followed by a computationally efficient intermediate level model, using layered elements, for the calibration of a lumped plasticity-based model suitable for the global analysis of structures. In this paper, the first research results are presented. In particular, a broad literature review concerning the mechanical characterization and analysis of TRM systems is collected. Then, the calibration of the numerical model, the validation through comparison with the results of experimental characterization tests available in the literature (tensile, shear bond, and in-plane shear tests) and a sensitivity analysis are reported. Nonlinear static analyses were performed, considering the nonlinearity of the composite material components and interfaces. The model was capable of accounting for the main parameters affecting the behavior of the composite material, such as the reinforcement ratio and orientation, the mortar characteristics and the wire–mortar interaction and proved to be a valid tool to investigate the optimization of TRM applicative details.