Reliability and cost analysis of selected repair methods of the new TR Instandhaltung

Abstract

In Germany, the new Technical Specification for Maintenance (TR Instandhaltung) forms the basis for planning, management, and implementation of maintenance measures on reinforced concrete structures. In the case of chloride‐induced corrosion, different concrete repair methods are specified therein for defined depth‐dependent chloride concentrations in relation to the concrete cover, following thus a prescriptive approach. In contrast, a full‐probabilistic, performance‐based approach sets limits to the so‐called “reliability index” (β). These limits are related to a maximum accepted probability of occurrence of an unwanted event, which in the case of chloride exposure, is the corrosion of the reinforcement. Since the value of β depends inherently on the depth‐dependent chloride concentration and the concrete cover, the limits set on them by the TR must be related to an implicit value of β. Therefore, in this contribution, these limits were analysed and evaluated. Additionally, the resulting costs of each method were estimated and analysed in terms of β at the time of the repair. Both the limits and the resulting costs provide helpful information in the context of a performance‐based approach for the through‐life management of reinforced concrete structures.