Structural tests on 43- and 45-year-old pre-stressed concrete bridge for reinforcement effect of PSC-I girders reinforced by external strand tendons

In this study, the flexural behavior of pre-stressed concrete-I (PSC-I) girders was investigated to intuitively and more accurately evaluate the structural behavior and load-carrying capacity increase of PSC-I girder bridges more than 40 years old and reinforced by the external pre-stressing (PS) tendon reinforcement method. Many bridges in South Korea, which were constructed after the 1960s, exhibit a significantly low load-carrying capacity due to aging and the application of loads that are different from originally designed loads. To improve the load-carrying capacity and working load of these old bridges, reinforcement methods that use external PS tendons have been conventionally used. However, the evaluation of the load-carrying capacity of a bridge and the calculation of the number of external tendons for reinforcement are performed through the vehicle load test within the working load range of the bridge. Most of the studies conducted so far have been limited to the calculation of the loss of the members required for the reinforcement of the bridge or their structural behavior. In this study, a flexural failure verification experiment was performed on PSC-I girder bridges that were constructed based on the standard design of the 1960s to verify the reinforcement effect of PS tendons. The target of the experiment was the girders of PSC-I girder bridges designed more than 40 years ago based on the working loads of DB-18 and DB- 24.