Concrete structures are generally designed on the assumption that they will require no maintenance during their service life. The experience with reinforced concrete structures in the severe marine environment shows that this assumption is not valid. Almost everywhere in the world it is possible to find coastal structures, even some relatively new ones, which contain cracked or spalled concrete usually involving corrosion of the reinforcement. For most concrete structures, the typical situation during operation of the structures is that maintenance and repairs are mostly reactive, and the need for taking appropriate measure is usually realized at a very advanced stage of deterioration. For chloride-induced corrosion, repairs at such a stage are both technically difficult and disproportionately expensive compared to carrying out regular condition assessments and preventive maintenance. Therefore, for all concrete structures where high safety, performance and service life are of special importance, regular condition assessment and preventive maintenance should be carried out including chloride profiles, potential mapping, local inspection, etc. For all concrete structures in chloride-containing environments, however, special procedures for monitoring and control of chloride penetration during operation of the structures are needed. The establishment of such procedures should always be an impartment and integral part of the durability design. In this paper, some procedures for the preventive maintenance are described and discussed in more detail.
