ABSTRACT
Due to their advantages, many reinforced concrete road bridges were built according to the Gerber scheme in which the so-called half-joints represent a key structural component. Besides their advantages, some drawbacks can be found in this type of bridge, mainly related to the deterioration process of the half-joints that leads to reinforcement corrosion and consequent concrete cracking and spalling. Therefore, many bridges may need over time specific retrofit interventions to guarantee the required level of safety. This paper first describes the retrofit techniques currently available in the literature. Numerical simulations are then carried out to investigate the effectiveness of a specific technique based on post-tensioning. Refined nonlinear finite element models were used to characterize the post-tension effects on the load-bearing capacity of a case study half-joint also in presence of simulated chloride-induced corrosion, and to outline the optimal prestress level to be used to obtain the wanted performance improvements.
