This paper deals with the assessment of remaining service life of a cooling water intake concrete structure (CWICS) subjected to corrosion due to chloride attacks. Field and laboratory tests were performed to determine the current existing condition of the structure. Both destructive and nondestructive tests were employed to obtain the parameter needed for the assessment. Based on the current condition and test results, structural analysis was carried out and the remaining safety factor of CWICS was determined. From the analysis, it was found that most concrete elements of CWICS had safety factor greater than unity and might fulfil its intended service life up to the year 2033. However, fewer elements require immediate strengthening to extend their service life. 1. Introduction Corrosion of reinforcing steel due to chloride attack is considered to be the primary cause of concrete deterioration of reinforced concrete structure [1]. This factor combined with poor practice in detail design, bad supervision, and bad construction execution lead to early deterioration of concrete structures. Concrete structures built 30–40 years ago often do not comply with the present day and more modern code requirement for durability. For example, most of the present day concrete codes specify that the minimum cover for concrete structures built in marine environment is 65？mm [2], whereas the corresponding minimum concrete cover during that time is around 50？mm. Furthermore, theoretical foundation of chloride penetration in concrete structure was not yet fully developed and well understood at that time. This lack of knowledge and understanding on concrete deterioration mechanism lead to nonintended faulty concrete practices. Therefore, it is not surprising that older concrete structures often has durability problem before their design life has expired. It is also expected for concrete structures built in a tropical country such as Indonesia to have higher corrosion rate than that of concrete structures built in temperate or cold region [3]. This higher corrosion rates are caused by higher average temperature and higher humidity experience by concrete structures along the years. Furthermore, workmanship and construction practice in Indonesia is not as good as those in a developed country. All of these factors may lead to early deterioration of concrete structures and shorten the service life of concrete structure. 2. Case Study This paper presents a study of remaining life assessment [4] of cooling water intake concrete structure (CWICS) at Indonesia. The study is comprised
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