Ali, Jamal IbrahimUnal, Alptug2026-02-102026-02-1020261735-05222383-3874https://doi.org/10.1007/s40999-025-01181-2https://hdl.handle.net/20.500.13091/12985Unal, Alptug/0000-0003-2945-8325In reinforced concrete industrial structures under seismic and service loads, unexpected critical damage may occur in areas where secondary beams are connected to main beams. Under these loads, secondary beams may cause localized damage to the main beam or partial collapse of the structure. In this experimental study, two methods were investigated for preventing the damage caused by secondary beams to main beams, especially in industrial buildings. In the first method, the main beam was strengthened with carbon fiber-reinforced polymer (CFRP) and glass fiber-reinforced polymer (GFRP) textile types to prevent any damage to the main beam caused by the secondary beam, with a design replicating existing industrial structures. In the second method, the potential for damage to main beams due to secondary beams in newly constructed industrial buildings was addressed through the implementation of a novel reinforcement arrangement during the project design phase. Thus, the effect of the combined use of horizontal bent-up bars and reduced stirrup spacing, rarely seen in the literature, was investigated. Additionally, rather than applying fiber-reinforced polymer (FRP) confinement along the entire length of the beam, as is often seen in the literature, the effectiveness of a more practical, material-efficient strengthening strategy was examined. This strategy involved applying FRP only to the critical areas of the region where the secondary and main beams were connected. A total of six test specimens were examined, including one reference specimen, two strengthened specimens, and three specimens with a novel reinforcement arrangement. These specimens were subjected to monotonic loading in a three-point bending apparatus. The load-displacement, stiffness, and energy consumption curves of the tested elements were drawn; the ductility values were determined; the crack distributions were examined; and the failure modes were identified. The results showed that strengthening the area where the secondary beam intersected the main beam with FRP textiles increased the main beam's load-carrying capacity, initial stiffness, and cumulative dissipated energy by 36.84%, 72.11%, and 3.90%, respectively. Additionally, reducing the stirrup spacing and using a horizontal bent-up bar increased the main beam's load-carrying capacity, initial stiffness, cumulative dissipated energy, and ductility by 18.97%, 38.19%, 53.81%, and 6.31%, respectively. This study reveals that both the FRP strengthening methods and the combined reduction of the transverse reinforcement spacing and use of horizontal bent-up bars are suitable methods achieving significant improvement of the behavioral properties of test elements compared to reference specimens.eninfo:eu-repo/semantics/closedAccessSecondary BeamMain BeamStrengtheningCFRPGFRPHorizontal Bent-Up BarArticle10.1007/s40999-025-01181-22-s2.0-105026386618