Durability design of reinforced concrete structures with stainless steel reinforcement

Stainless steel reinforcing bars can be a suitable choice to guarantee the target service life of reinforced concrete structures exposed to aggressive chloride-bearing environments. Usually the choice of the stainless steel grade is based on experts opinion or practical codes, whilst the adoption of performance-based approaches would allow to quantify the service life of a structure and hence to quantify benefits in relation to the life cycle costs. Unfortunately, in many of the nowadays available performance-based approaches, especially the Model Code for Service life design proposed by the fib, designers fail in finding any indication for the application of stainless steel bars. In this paper a proposal for implementing the use of stainless steel reinforcement in the fib Model Code is presented. In particular, a procedure to estimate the critical chloride threshold for stainless steels, which takes into account the role of the factors which can affect it, is suggested.