Full-Scale Experimental Study of Shear and Flexural Behavior of 16-m Retired Reinforced Concrete T-Beams

Most of the existing engineering structures were built in the last century and have been in service for decades. However, environmental degradation may lead to a reduction in structural performance and service life. The mechanical property data of full-scale structures, such as bridges, are essential for structural health monitoring. For this purpose, five (half) reinforced concrete (RC) T-beams were removed from a retired 31-year-old bridge and subjected to destructive testing. Two loading points were employed, and the flexural and shear capacities of the retired T-beams were studied. The results showed that all the retired beams held high load capacities (exceeding 1400 kN). The two flexural test beams exhibited a high ductility, and the three shear test beams all failed. In addition, the existing cracks in the flexural test beams reopened when the load exceeded 200 kN, while it was 300 kN for the shear test beams. The load-carrying capacity experimental values of the test beams were compared with the ones calculated according to Chinese code JTG-3362-2018; it was shown that the retired T-beams still maintained a high degree of safety margins despite initial defects. The experimental results are expected to provide a reference for the assessment of in-service RC bridges.