Design of the out-of-plane strengthening of masonry walls with textile reinforced mortar composites

Masonry walls are particularly vulnerable against out-of-plane seismic actions. Textile Reinforced Mortar (TRM) composites, made of high strength fabrics embedded inside inorganic matrices, can be efficiently integrated with traditional strengthening techniques to improve their seismic capacity, as demonstrated by a number of experimental investigations. Nevertheless, apart from the ACI 549.4R-13 guidelines, no design instructions addressed to practitioners have been developed so far. This paper proposes an approach for the evaluation of the out-of-plane flexural capacity of masonry walls reinforced by externally bonded TRM systems. The mechanical properties of the reinforcements are derived by combining the results of tensile tests on textile specimens and TRM-to-substrate shear bond tests. The bending strength is evaluated through a cross-sectional analysis based on strain limit states to fulfil compatibility. Analytical predictions are in good agreement with experimental results, indicating that the method is suitable for engineering design purposes.