Service-life assessment of existing precast concrete structure exposed to severe marine conditions

Abstract

The overall performance of a concrete structure is considered to be a key issue when determining its service life. The widespread use of precast concrete and consideration of durability as a design parameter in most of the international codes have the goal of achieving concrete structures with better durability. Nevertheless, the early deterioration of concrete is still common in a large number of concrete structures, which reduces the service life. This paper presents a case study of an existing precast concrete cooling tower for a thermal power station subjected to severe marine exposure conditions, which showed symptoms of serious deterioration after operating for three years. The main goal of this study was to clarify the origin of the accelerated deterioration of the structure. Wetting-drying cycles were identified as the main cause of the early deterioration of the structure. Furthermore, estimations on its remaining service life were made considering the accelerating effect of the wetting-drying cycles. Finally, the variation in the safety factor of the main structural elements was evaluated.