Efecto de la difusión de ión cloruro en el comportamiento de acero galvanizado en estructuras de hormigón armado. Resultados preliminares

Galvanized steel behavior in concretes of different types of cement is very important for new mega construction projects with requirements of durability in highly aggressive environments such as sea water, in harbor structures as in mining projects that use sea water in their processes. To emulate conditions of this type of project, it was used W/C ratio 0.45. Measurements of mechanical and physical properties of concretes based on Pure Portland cement and Pozzolanic Portland cement were made: compressive strength, capillary absorption, total porosity and capillary absorption coefficient, resistance to water penetration, capillary absorption and effective porosity were calculated. The specimens made with ordinary steel and galvanized steel were subjected to drying semi-immersion cycles in 2.56M sodium chloride solution, and measurements of corrosion potential, polarization resistance, corrosion current, analysis of chlorides and pH were made periodically. The results justify the conclusion that regardless of type of cement used in concretes investigated, galvanized steel shows passivity to 19 drying semi-immersion, and ordinary steel is active from cycle 16. After the cycle 19 galvanized steel 19 in concrete made with pozzolanic Portland cement begins to show activity in a saline environment. However, the high salt conditions are not yet enough to activate the galvanized steel in concrete with ordinary Portland cement.