A Study on Electron Probe Microanalysis of Concrete Deterioration in Aging Open Channels in Cold Regions

Abstract

Synopsis: Open channels made of reinforced concrete are subject to freeze-thaw cycles when used in cold regions for a long period. We conducted electron probe microanalysis to analyze surface elements of core samples from the exposed parts of channel sidewalls, and examined the deterioration of the concrete on the inner and outer surfaces of the sidewalls. Our study revealed that freeze-thaw cycles cause cracks in the outer surfaces that serve as passageways for water, and that the leaching of calcium around the cracks and the penetration of carbon dioxide into them cause calcium recrystallization and sulfur diffusion. Our study also showed that the calcium that leaches into the air voids near the inner surfaces of cracks recrystallizes, causing blockage of air voids.