Effect for Environments Factors such as Supplying Water by Carbonation Mechanism on Real Concrete Structures

Abstract

Progress of carbonation of actual structures is greatly affected by material factors such as kind of cement, water cement ratio, mix proportions and environmental factors such as temperature, humidity, carbon dioxide concentration and exposure to rainwater. In this study, we investigated carbonation depth in real concrete structures constructed using blast furnace cement about 50 years ago under various rainwater exposure conditions. In addition, the mechanism of carbonation progression in blast furnace concrete was examined using chemical analysis. The results of this investigation revealed that exposure to rainwater has a remarkable influence on the progress of carbonation, that there is a relationship between pH level and calcium carbonate production, and that the mechanism of carbonation progression thus differs according to the environment.