Effect of Saline Exposure on the Bond Performance of TRM Composites

Textile Reinforced Mortar (TRM) has emerged as a widely adopted solution for strengthening existing structures, particularly masonry and historical heritage buildings, due to its favorable mechanical and durability properties. As TRM systems become more prevalent in structural strengthening, it is crucial to develop a comprehensive understanding of their long-term performance. Although extensive research has been carried out on TRM durability under various environmental conditions, there remains a need for detailed experimental investigations focusing on bond behavior, especially in saline environments. A significant gap also exists in formulating standardized aging procedures that simulate the effects of salt-induced degradation. This study addresses that gap by examining the bond performance of TRM composites subjected to saline exposure for 1000 and 3000 h. Two commercially available textiles—glass and basalt fibers—were embedded in a lime-based mortar, and the experimental campaign included compressive and flexural tests of the mortar, as well as single-lap shear tests for evaluating bond behavior. Results indicate that saline conditioning can temporarily enhance bond strength in basalt-TRM, but ultimately leads to greater brittleness and mechanical property degradation, whereas glass-TRM shows a more consistent, gradual decline in performance. These findings underscore the importance of adopting tailored protective strategies and extending exposure durations in future research to capture the full range of degradation effects, thereby ensuring the long-term reliability of TRM systems in chloride-rich environments.