Durability of textile-reinforced mortar in acidic environments: effects of acidity level and exposure time on tensile performance

Textile Reinforced Mortar (TRM) systems are gaining attention as an innovative solution for structural reinforcement, particularly in masonry structures. While their short-term mechanical performance is well-documented in the literature, significant gaps remain in understanding their long-term behavior, especially under extreme environmental conditions. In particular, the effects of high-intensity acidic environments on TRM composites are largely unexplored. To address this gap, this study investigates the long-term durability and mechanical performance of TRMs through an accelerated aging campaign under varying acidic conditions. Using a lime-based mortar and a glass-fiber textile, a total of 315 specimens, including TRM tensile coupons, textile reinforcement, and mortar samples, were exposed to sulfuric acid solutions with pH levels of 1.5, 2.0, and 3.0 for durations of 1000, 3000, and 6000 h. Reference conditions included water immersion and climatic chamber environments. Material characterization tests, such as compressive and flexural tests on the mortar and direct tensile tests on TRM coupons and textile reinforcement, were conducted to examine deterioration mechanisms and the mortar-textile interaction. Results show that acidic intensity and exposure duration significantly affect TRM performance, with high acidity leading to pronounced degradation and moderate acidity exhibiting slight strength gains. These findings bridge a critical knowledge gap, providing insights into the design and application of TRM in aggressive environments, particularly for masonry reinforcement.