Strength degradation analysis of an aging RC girder bridge using FE crack analysis and simple capacity-evaluation equations

•An FE crack analysis of an aging reinforced concrete bridge with presence of cracks was performed.•A simple capacity-evaluation equation was also proposed.•Depending on the type of cracking, the existing cracks may have serious structural effects.•Shear cracks may greatly reduce the load-carrying capacity and should be carefully monitored.

Aging reinforced concrete (RC) bridges require regular evaluation of structural integrity taking into account the actual deterioration of materials. This study selected a multi-span RC girder bridge with a service life of almost 80 years and used a mixed modeling approach for FE crack analysis and a simple capacity-evaluation equation to examine its severely cracked central girder, focusing on the effects of existing cracks on the structural behavior and load-carrying capacity. The study shows that depending on the type of cracking, the existing cracks may have serious effects on the structural integrity of the bridge. For a simple support girder, while the effects of central cracks can be ignored in principle, shear cracks may greatly reduce its load-carrying capacity and may even cause brittle failure of the structure.