This study aims to quantitatively evaluate the initial performance, critical performance, and effect of repairs for the reuse of RC beams by a roadmap model, focused on the conditions that cause the highest degrees of deterioration. First, as a method of grasping the load-carrying capacity and deformation performance after repairs, a static loading test was carried out after the repair was performed. At the same time, to investigate the effect of repairs using a nondestructive inspection method, the natural frequency was measured by impact vibration testing at each loading stage. Next, to examine the results of impact vibration tests, eigenvalue analyses were conducted using deterioration conditions and spring constant values as parameters, and where local reduction of bending stiffness to the beam could be considered rationally. In addition, by confirming the influence of spring constant value, which is a boundary of the beam during the process of eigenvalue analysis, it was possible to adopt a vibration mode that better reflects the condition of the frame, which was used as the evaluation index. Then, based on the index, mechanical behavior in several conditions and the evaluating result of repairs focusing on reuse were organized. Based on these results, we examined recommended countermeasures according to each situation and prototyped a roadmap model for maintenance.