###### Abstract  
Due to insufficient transverse reinforcement, the retrofitting of beam-column joints (BCJs) in existing reinforced concrete (RC) frame structures is commonly required to alter their brittle behavior. The construction industry has extensively embraced carbon-fiber-reinforced polymers (C-FRPs) as near-surface-mounted (NSM) reinforcement. Monitoring the performance of C-FRP retrofitting is crucial due to the wide range of factors influencing its effectiveness. A novel methodology has been implemented to assess the efficacy of the C-FRP retrofitting method in this study. This approach was validated through experimental investigation of full-scale BCJs, which were retrofitted with C-FRP ropes and subjected to cyclic loading. Furthermore, piezoelectric lead zirconate titanate (PZT) patches were placed on the NSM C-FRP ropes, and the electro-mechanical impedance (EMI) method was employed to monitor the retrofitting technique's performance. A combination of the commonly used statistical damage index root mean squared deviation (RMSD) and a hierarchical clustering-based approach (HCA) was used to assess the performance of the C-FRP retrofitting technique. The experimental investigation results strongly indicate the proposed approach's positive impact on the reliable assessment of C-FRP retrofitting performance. Thus, the proposed approach enhances the safety and resilience of retrofitted BCJs in RC structures. retrofitting monitoring; reinforced concrete (RC); beam-column joint (BCJ); carbon-fiber-reinforced polymer (C-FRP) ropes; hierarchical clustering approach (HCA); piezoelectric lead zirconate titanate (PZT) transducers 20 polymers (FRPs) are widely employed to retrofit existing RC buildings despite the various retrofitting methods. Even though there are numerous advantages of FRP retrofitting techniques, the minimal invasiveness and limited work interruption associated with FRP retrofitting are the primary drivers behind the significant increase in their implementation on existing RC structures. Numerous scholars globally have researched the effectiveness of FRP in repairing and strengthening structural elements exposed to seismic loading [7]. Those studies show the merits of using FRP to enhance the structural behavior of RC members, such as beams [8; 9; 10] and columns [11; 12]. Furthermore, studies published in the broad literature investigate FRP retrofitting-associated issues, including debonding failure, related to the interfacial interaction between FRP laminates or sheets and concrete substrates [13; 14; 15]. Recent studies have investigated the use of carbon FRP (C-FRP) as flexible ropes for strengthening RC members with remarkable results. Furthermore, researchers have examined the implementation of C-FRP ropes for strengthening shear-deficient reinforced BCJ. The C-FRP ropes demonstrate a notable capability to alter premature debonding, a primary drawback of FRP retrofitting methodologies, by forming closed stirrups. [PERSON] et al. conducted experiments that showed the efficacy of X-shaped C-FRP ropes used as near-surface-mounted (NSM) reinforcement for the joint's body [5]. Their findings indicate a substantial reduction in the shear deformation of BCJ, consequently enhancing its seismic performance. Furthermore, in terms of ensuring the structural safety of retrofitted RC buildings, it is of utmost importance to prioritize the development of a structural health monitoring (SHM) system capable of assessing the effectiveness of the retrofitting technique used in critical RC members [16]. This research is urgently essential because of the continuous aging of existing RC infrastructures [17]. Within the rapidly advancing technology of SHM, extensive research has been dedicated to damage identification, localization, and assessment of RC members [18]. However, conventional SHM methods are expensive and often insufficient, especially for challenging-to-access structural members, highlighting the importance of cutting-edge monitoring technologies.