Study of Deterioration of Concrete Structures in Port Sudan

Concrete structures in coastal areas are exposed to sever environmental conditions, such as high temperature and humidity, which influence strength, durability and behavior. This work is intended to represent and investigate the deterioration of concrete structures in Port Sudan, review and study the methods of repair used in Port Sudan and evaluate their effectiveness as well as suggest the proper procedure to avoid deterioration in new constructions at the design, and construction stages, and suggest the proper repair methods. The study reviewed durability of concrete and the causes of deterioration in concrete structures and how they can be prevented as well as diagnosis of causes and methods of repair. The study defined the problem by constructing a questionnaire which showed that (41.76%) of samples were deteriorated structures, and Althaora, Hadal and Hialkhaleeg are the most affected regions. Corrosion of steel reinforcement is a major cause of concrete deterioration where (75.5%) of deteriorated samples showed cover spalling, and (66.67%) presented longitudinal cracks parallel to reinforcement steel. Slabs were the most affected members (76%), while columns were (38%) and walls (64%). (68.89) of the rehabilitation was improper and this lead to annual repair where (55.6%) of rehabilitation was repeated 4 to 6 times in the last 10 years. Three building have been taken from the most affected regions; and the corrosion damage was investigated and diagnosed by visual 5 assessment, field test and laboratory test. Source of constituent material (fine aggregate and water), and soil form foundation were tested also, so as to support the field test. It shows as follow: Chloride ion and carbonation process are direct reasons of concrete corrosion damage as result of poor construction quality, low strength and inadequate cover to preventing the harmful environment and this is clear from comparing it by British Standard Specification (BS8110). The study recommends to ensure durability of concrete structures under the harmful environment, care must be taken in construction, especially cover depth, concrete density, and concrete placing as stated in British Standard Specification (BS8110). Also sulphate resistant cement should be used in foundations, as well as taking some other preventive measures. The study also recommends for future study of the behavior of different admixture use for concrete in Red Sea area. In addition to that new techniques should be used in preventing corrosion such as using bar coating by epoxy resins and Fiber reinforced polymers (FRP) as reinforcement