Semnan University Press Journal of Rehabilitation in Civil Engineering 2345-4415 14 1 2026 02 01 An Innovative FRP Pre-Stressing Device for Retrofitting Reinforced Concrete Beams 9326 10.22075/jrce.2025.36001.2213 EN Kian Aghani Ph.D. in Structural Engineering, Civil Engineering Faculty, Sahand University of Technology, Sahand, Iran Hassan Afshin Associate Professor, Civil Engineering Faculty, Sahand University of Technology, Sahand, Iran Karim Abedi Professor, Civil Engineering Faculty, Sahand University of Technology, Sahand, Iran Journal Article 2024 11 23 Fiber Reinforced Polymer (FRP) composites are commonly utilized for retrofitting concrete members. While this retrofitting approach offers numerous advantages, some challenges remain. Pre-stressing the FRP is a promising strategy to optimize the proficiency of this method by enhancing the effectiveness of the composite and delaying debonding failures. However, conventional pre-stressing methods require specialized equipment and anchorage solutions. This research introduces a device explicitly designed for pre-stressing FRP composites used in retrofitting of concrete beams and slabs. Eliminating the demand for hydraulic jacks, straightforward operation, and being lightweight are among the critical advantages of the device. Furthermore, the device’s dimensions and weight are adjustable to take into account various composite sizes, and desired pre-stress levels, ensuring economic and practical feasibility. This study details the design and construction of the device, followed by an evaluation of its performance in pre-stressing carbon fiber reinforced polymers (CFRP) for retrofitting reinforced concrete T-beams via experimental tests. The results showed the potential of the proposed device for utilization in retrofitting applications. Also, a finite element model of the device and the associated analysis methodology are presented. https://civiljournal.semnan.ac.ir/article_9326_b620f0c74a29d5cd1c8c6f51c25230a1.pdf