Corrosion initiation period for stainless steel reinforcement in concrete structures

Abstract

The designed service life of reinforced concrete structure is often shortened when disposed in aggressive environments. In certain situations, stainless steel reinforcement may be an appropriate replacement to attain a higher level of durability. This paper presents the findings of an experimental study conducted to determine the critical chloride threshold for two types of stainless steel reinforcement (UNS S40977 and UNS S32001). For each steel grade, a prediction model for the corrosion initiation period was obtained, applying the electrochemical test data in a Monte Carlo analysis. Results show that if the initiation period is taken as the corresponding for a 7% corrosion probability, that will occur at 6.5 years of age for carbon steel and over 150 years for UNS S32001 stainless steel.