Carbonation profile of old and new reinforced concrete structures in Intramuros, Manila

Carbonation of structure is inevitable through the years. It is a condition where structures deteriorate due to the penetration of carbon dioxide to the reinforced concrete. A carbonation profile would be beneficial in the maintenance and retrofitting of structures as it provides the carbonation condition of structures needed in determining its service life. The purpose of this study is to determine the carbonation profile of Intramuros, Manila. The carbonation profile will aid the Civil Engineers in predicting the service life of the structure. In addition to that, this will help them determine the carbonation depths of the structure thus making it easy for them to identify the structures that need to be retrofitted. The specimens were extracted from selected structures in Intramuros, Manila. These specimens were tested for its moisture content using the conventional oven drying method and Phenolphthalein Solution using Phenolphthalein powder. The results showed that the age does not affect the carbonation depth of the structure given that it is well maintained (i.e. repainted regularly). Several factors also affect the carbonation depth of the structures. The presence of moisture content is necessary for the carbonation of concrete. It was found out that moisture content was the leading cause of carbonation, however, too much moisture impedes the carbonation of a structure. Moreover, the proximity of the structure to the coast affects its carbonation depth structures near the coast experience increase on carbonation depth. The carbon dioxide concentration surrounding the structures was identified and it was found out that higher amount of carbon dioxide increase the carbon depth of the structures. On the other hand, temperature and humidity have little effect on the increase of carbonation depth. In addition to that, this study also shows that elevation has little effect on the rate of carbonation