Secondary Cracks and Mechanical Behavior Prediction of Concrete Segments After FRP Confinement

It is quite challenging to use tunnel segment as a repair experiment object due to its large size, the difficulty of installation, and loading inconvenience. To tackle this problem, a 45° symmetrical-bevel RC plate has been employed to substitute segment and conventional RC plate, and to investigate the mechanical behavior of secondary crack problems for concrete segments after repair by polymeric matrix and fiber reinforcement polymers (FRPs). Moreover, elaborate five numerical models of segments were established by means of experiments and 3D finite element method. The prediction results indicated that the mechanical properties of using 45° symmetrical-bevel RC plate were in good agreement with the concrete segments (81.30%). In contrast, those using conventional RC plate showed a larger disagreement (57.49%). Versus and after repair by PM and FRPs, the secondary cracks of concrete segments were improved by 2.86–29.52% of compressive strength compared with the primary cracks. It demonstrated that the experimental results and the simulation results matched well (close to min. 87.89%).