Atmospheric corrosion behaviors of reinforcement steel in reinforced concrete in a coastal city as Havana was carried out. Concrete quality was characterized before to expose the reinforced concrete specimens in outdoor exposure condition. An outdoor exposure site at a distance of 10 m from the sea was selected in coastal city of Havana, Cuba. Three reinforced concrete specimens (RCS), one for each water/cement ratio 0.4, 0.5 and 0.6 with concrete covering thicknesses 20 mm and 40 mm were exposed to outdoor exposure condition. Corrosivity categories of the atmosphere in the outdoor exposure site were Very high (C5) and Extreme (CX).  Atmospheric corrosion behaviors of reinforcement steel in reinforced concrete specimens served to obtain service life from the sum of Time-to-corrosion-initiation and Time to corrosion with induced cracking in reinforced concrete structures in a coastal city as Havana, Cuba. Compressive strength and ultrasonic pulse velocity are necessary test but not enough in the concrete quality characterization. Percentage of effective capillary porosity should be determined as a deeper factor for concrete quality characterization. Designs conditions for the concrete elaboration with a quality high and more durable were established, before to carry out the building works in a coastal city as Havana City, as well as in all shoreline north and south of Cuba with the purpose to increase the service life in reinforced concrete structures.