Durability design of reinforced concrete bridges using time-dependent reliability

This paper presents an innovative approach to designing the durability of reinforced concrete (RC) bridge beams, emphasising time-dependent reliability. Unlike traditional deterministic methods, this new procedure integrates the probabilistic aspects of material wear, environmental effects and varying loads over a bridge’s lifespan. It highlights the necessity of durability design for sustaining the long-term performance of RC structures and promotes reliability-based design solutions. The method considers initial resistance variability, resistance degradation, increasing traffic loads and a realistic minimum safety reliability target. Using real data, it models time-dependent traffic loads and resistance, and sets a minimum reliability index for bridge construction based on safety and actual bridge conditions. A case study shows the practicality of the new procedure, indicating significant improvements over conventional methods. The study also points to areas for future research, such as developing more accurate models.