Rehabilitation of Underground Garages—A Risk-Based Decision-Making Process

In recent years, a main research focus has been set on the development of performance-based design concepts for the durability of concrete structures. These concepts are based on three general principles: (1) the use of validated material laws (models); (2) the adequate quantification of the material resistance and the environmental loads; and (3) a safety concept on a probabilistic basis. The latter sets a maximum allowed probability of occurrence of an undesired limit state. Therefore, we analysed numerous well-documented inspections of underground parking garages that underwent rehabilitation works. The focus was set on chloride-induced corrosion since it was the main reason for the rehabilitations. Due to limitations in the available information, we estimated the reliability index using approximate methods. We estimated the reliability index at which both the columns and the walls of the different projects were rehabilitated separately. We afterwards compared the estimated reliability indices to values recommended in the literature and to the used rehabilitation method. The estimated reliability index seems to agree with the recommendations for the target reliability index found in the literature. We did not find a significant difference between the reliability index values for which the two different rehabilitation methods were applied, suggesting that other factors should be considered.