In-Plane Cyclic Performance of Masonry Walls Retrofitted with Flax Textile–Reinforced Mortar Overlays

Abstract

This paper investigates the performance of flax textile–reinforced mortars (FTRM) as a retrofitting solution for unreinforced masonry. Six medium-scale walls were subjected to in-plane cyclic shear tests. Four of the specimens were retrofitted on both sides with one or two layers of flax textiles embedded in lime-based mortar. One bare wall and one wall strengthened only with lime-based mortar were examined as reference samples. FTRM provided up to 118% higher shear load and ultimate drift and promoted the development of energy dissipation mechanisms, while ensuring structural integrity. Based on the experimental evidence, the contribution of individual shear resisting mechanisms was assessed and existing design models were found to overestimate the stress that can be developed in the flax textile when two layers were applied. A new design model that adopts a more rational limiting strain value and accounts for the contribution of the mortar and the unique mechanical performance of FTRM systems was proposed and validated against an experimental database, including natural and advanced textile-reinforced mortar systems.