Condition Assessment and Preventive Maintenance of Concrete Structures in Severe Marine Environment

Abstract

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.

Chloride ion transport mechanism in concrete due to wetting and drying cycles

“…Chloride ion-induced corrosion of concrete reinforcement is one of the primary factors affecting the durability of concrete structures [1][2][3]. This effect is particularly pronounced in environments with wetting and drying (W-D) cycles (e.g.…”

Effect of Sulfate Concentration on Chloride Diffusion of Concrete under Cyclic Load

“…The existence of chloride ions and sulfate ions in salt lakes and saline soils in northwestern China leads to the corrosion and deterioration of road and bridge structures. For structures in the north region, the large amount of usage of deicing salts and the existence of dynamic vehicle loads in winter aggravate the structural damage, which, in turn, influence the internal pores and microcracks of concrete, further affects the transport behavior of chloride ions in concrete [ 1 , 2 ], and induces corrosion issues of the reinforcing steels during the regular service life [ 3 ].…”