Monitoring of Textile Reinforced Composites Externally Bonded to Existing Concrete Substrates Through NDTs

Externally bonded reinforcement (EBR) systems are widely used for strengthening and repairing existing structures, since they can provide significant performance enhancements without significantly affecting geometry, mass and stiffness of the considered structure. In the last years, among others, textile/fabric reinforced cementitious composites (Textile Reinforced Mortar (TRM), Fabric Reinforced Cementitious Matrix (FRCM), Textile Reinforced Concrete (TRC), etc.) are getting more popular as a retrofitting material. However, the effectiveness of EBR systems depends not only on the reinforcement strength but also on several bond related factors that can affect the reinforcement exploitation and their failure modes. Understanding these failure modes is important both for the design and for the assessment and monitoring of retrofitting interventions. To address this issue this paper will present some preliminary results on textile reinforced composites-to-concrete substrate bond behavior, investigated for different failure modes, and monitored through nondestructive techniques (NDTs) including digital image correlation and acoustic emission.