The influence of secondary reinforcement on a strut‐and‐tie model for the design of reinforced concrete corbels

In precast concrete structures, optimizing the design of corbels by considering the contributions of secondary reinforcement elements can significantly improve construction economy, especially when corbels are repeated multiple times. This paper proposes a strut‐and‐tie model for reinforced concrete corbels subjected to vertical and/or horizontal loads, focusing on the effective utilization of secondary reinforcement, which is often neglected in conventional load capacity calculations. The proposed model was validated using experimental data from 397 corbels reported in the technical literature. Additionally, a comparative analysis was performed with three reference models to evaluate its performance. Key parameters, such as the horizontal‐to‐vertical load ratio and corbel aspect ratio, were analyzed for their influence on corbel strength. The results demonstrated that the proposed model provides a broader and safer application range compared to the reference models, with approximately 99% of the tested corbels aligning with its predictions. Furthermore, incorporating secondary reinforcement in the proposed model enhanced structural efficiency, yielding a mean strength improvement of approximately 22% based on the tie‐yielding failure criterion. These results highlight the model's potential to achieve both safety and economic viability in the design of precast concrete corbels.