Corrosion of reinforced concrete has been usually associated with chloride ions. However, another cause of rebar corrosion is carbonation of concrete. Carbonation-induced corrosion tends to develop later, proceeds at slower rates than chloride-induced corrosion, and leads to uniform steel corrosion that would accelerate the crack formation and decrease the structure service life. In tropical environments away from the chloride influence, carbonation-induced corrosion would be the main
corrosion mechanism in reinforced concrete. The objective of this investigation was to study the effect of carbonation on concrete buildings located in urban environments. Preliminary results based on the
analysis of the carbonation depth, concrete strength, porosity, electrical resistivity, and water absorption shows an influence with the elevation. The results are compared with those obtained in a previous
investigation in concrete buildings located in tropical marine zones. Estimates of the length of the corrosion initiation period based on the measured carbonation coefficients, and implications on current
design criteria are presented.
Keywords" Carbonation, Compressive strength, Concrete, Corrosion, Porosity.