การประเมินความเสียหายและการเสื่อมสภาพเนื่องจากคาร์บอเนชันของอาคารคอนกรีตเสริมเหล็กในเขตเมืองของจังหวัดชลบุรี

Abstract

Reinforced concrete (RC) structures exposed to carbon dioxide environment causes rust of the reinforcing steel. Consequently, it reduces the ability to withstand loads and shortens the service life of the concrete structures. Therefore, the assessment of the risk of rust caused by carbonation can be used for designing, planning, and maintaining RC structures. This research aimed to investigate carbonation depth of RC buildings in urban area of Chon Buri province. Carbon dioxide (CO2) concentration and relative humidity (RH) of the environment, cover thickness and compressive strength of RC buildings, and carbonation depth of RC buildings were measured. The samples of RC buildings in urban area of Chon Buri province were used for this study. The data were used to analyze the risk of rust caused by carbonation and to predict repair-free service life of RC buildings using Fick's First Law of Diffusion Equation and durability design of carbonation structure of Department of Public Works and Town & Country Planning (DPT 1332-55). The research results revealed that the RC buildings had the average cover thickness and the compressive strength of 31-43 mm and 225-367 kg/cm2, respectively. Besides, the average carbonation depth and coefficient of RC buildings were 5-53 mm and 0.18-2.73 mm/ year0. 5, respectively. Finally, the proposed method of Fick's First Law of Diffusion Equation and DPT 1332-55 could predict and calculate the repair-free service life of RC buildings exposed to CO2. The results of this study could be used for designing, planning and maintaining RC building exposed to the carbonation environment as well as preventing damages that would occur in the future.