Monitoring of reinforced concrete bridges retrofitted by external tendons

Monitoring of reinforced concrete bridges retrofitted by external tendons An established retrofitting method for bridges with deficits in their load bearing capacity is the installation of external tendons to increase the lifespan of the structure. A critical detail of the retrofitting is the anchorage block, where significant forces have to be introduced into the existing superstructure. Therefore, the anchorage blocks of three bridges in Hessen were monitored. They were fitted with extensometers, strain gauges were installed on prestressing rods and the temperature was recorded. Furthermore alert protocols were established, to detect potentially critical situations. The effects of different construction stages were tracked. The influence of short- and long-term temperature changes on the readings was assessed. In summary, the monitoring provided valuable insights into the structural interaction between the existing superstructure and the elements of the retrofitting.