Survey on Carbonation Rate of Pedestrian Bridge Structures in Chonburi Community Area

Abstract

This study was an investigation on the carbonation depth of pedestrian bridge structures in Chonburi community area. Carbon dioxide (CO₂) concentration and relative humidity (RH) of the environment, and cover thickness, compressive strength and carbonation depth of concrete of pedestrian bridge structures were measured. In this study, the pedestrian bridge structures used 4 bridges in Chonburi community area. The study results were analyzed the occurrence on the carbonation depth of pedestrian bridge structures. The predict for free service life of pedestrian bridge structures in both by Fick's first law of diffusion equation and durability design of carbonation structure of Department of Public Works and Town & Country Planning were considered. The results indicated that the pedestrian bridge structures had the average of the cover thickness and the average of the compressive strength as 31-44 mm and 307-367 kg/cm², respectively. Besides, the average of the carbonation depth and the average of the carbonation coefficient of pedestrian bridge structures were 32-41 mm and 6.4-7.1 mm/year^0.5, respectively. Finally, the proposed method to Fick's first law of diffusion equation and durability design of carbonation structure of Department of Public Works and Town & Country Planning can predict and calculate the free service life of the pedestrian bridge structures exposed to CO₂. The result can be used in the design, planning and maintenance of pedestrian bridge structures faced by the carbonation environment as well as preventing damage that will occur in the future.