Assessment of Corrosion in Offshore R.C. Piers and Use of Microsilica to Reduce Corrosion Induced Oxidation (A Case Study of Wharves 11 and 12 in Imam Khomeini Port, Iran)

Deterioration due to corrosion is an important issue affecting the durability, strength, and sustainability of buildings and structures. Many cities are located in coastal areas and many reinforced concrete structures in these areas are exposed to chloride aggressive marine environments. Therefore, it is important to provide protection and offer appropriate repair methods of buildings vulnerable to the degrading effects of corrosion. The present study sets out to identify and evaluate the causes and extent of corrosion observed in Piers 11 and 12 in Imam Khomeini port, Iran. The microsilica is used to reduce corrosion. In order to achieve the above-mentioned goals, a number of experimental field tests were performed to determine the level of concrete condition in terms of reinforcement corrosion. Some tests were conducted to determine the conditions of concrete piers in terms of reinforcement corrosion. Then a reinforcement corrosion current density test is performed using a potentiostat involving a placement process; with different water-to-cement ratios and superplasticizers, the microsilica content was 5%, 10%, and 15%. Microsilica can serve as an alternative to cement and was measured according to the ASTM standards. Microsilica was exposed to aggressive conditions at different periods and a concrete compressive strength test was performed. The results showed that the compressive strength and corrosion resistance of the concrete increased for concrete mixture containing 10% microsilica with a water-to-cement ratio of 34% and a superplasticizer ratio of 6%.