Resumen
Harsh environmental conditions create an added challenge to the durability of structures in Middle Eastern regions such as the United Arab Emirates (UAE) and Qatar. Engineers in this region must take into account the effect that corrosive conditions will have on new build structures and find a way to counteract these elements to achieve a substantial service life. Common challenges include high temperatures, high humidity, salt spray near coastal areas, high water tables with extremely saline water, and soils with chloride deposits. All these elements above and below ground combine to make a highly corrosive environment that fosters accelerated deterioration of reinforced concrete structures. To address these challenges, engineers specify corrosion-inhibiting admixtures to slow the corrosion and eventual deterioration of reinforced concrete structures. One common admixture is calcium nitrite, but it tends to accelerate concrete set time and increase shrinkage. As projected chloride exposure levels increase, so does the required dosage rate and, along with it, undesirable side effects. Calcium nitrite also isn?t considered safe for use in potable water structures, making it inappropriate for such applications. An alternative corrosion inhibitor gaining popularity in Middle East structures is based on amine carboxylate Migrating Corrosion Inhibitor (MCI) technology developed by Cortec Corp., a U.S. company that has patented several variations of this technology. MCIs can be applied to protect new and existing structures via admixtures, surface treatments, repair mortars and other media. MCI diffuses through concrete pores from areas of higher concentration to areas of lower concentration, adsorbing on embedded steel reinforcement. This protective layer guards the metal from interacting with corrosive species (e.g., moisture and chlorides) at both the anode and cathode of a corrosion cell. The MCI layer delays the initiation of corrosion and significantly reduces corrosion rates once started.