Flexural Strengthening of Reinforced Concrete Beams with Prestressed L-Shaped Sections: A Numerical Investigation

This study introduces and numerically validates a novel method for the flexural strengthening of reinforced concrete (RC) beams using prefabricated, L-shaped prestressed concrete sections. A Finite Element model was developed in Abaqus and validated against existing experimental data for an unstrengthened RC beam. A comprehensive parametric study was then conducted to assess the performance of the strengthened system, focusing on the effects of prestress level and tendon arrangement. The results demonstrate the exceptional efficacy of the proposed technique. The beam's flexural capacity was significantly increased, with the optimal configuration showing a 428.7% enhancement in yield moment compared to the reference beam. Furthermore, the method substantially improves the structure's ductility and energy dissipation capacity, with inelastic energy dissipation increasing by up to 59.9% and damage-related energy dissipation by up to 191%. A direct comparison revealed that the proposed method's performance is approximately 2.5 times greater than strengthening with advanced Ultra-High Performance Fiber Reinforced Concrete (UHPFRC) jackets. This numerical proof-of-concept confirms that the proposed technique is a highly promising and efficient solution for structural retrofitting.