Title: Effect of Temperature on Chloride Diffusion in Saturated Concrete
Author(s): B. Touil, F. Ghomari, A. Bezzar, A. Khelidj, and S. Bonnet
Publication: Materials Journal
Volume: 114
Issue: 05
Appears on pages(s): 713-721
Keywords: activation energy; coefficient of migration of chlorides; pozzolan; temperature
Date: 9/1/2017
Abstract:
The degradation of reinforced concrete (RC) structures exposed to marine environments is largely due to the transfer of chloride ions through the material. The prediction of the penetration of these ions in the concrete by the diffusion coefficient is a fundamental indicator for the characterization of its durability. Tests simulating chloride diffusion in saturated areas are developed at a constant temperature; however, in reality, the temperature fluctuates with the seasons and diurnal variations. To simulate the coupled temperature diffusion of chloride in RC structures in permanent contact with the Mediterranean Sea, an experimental program was developed in the laboratory to assess the migration coefficients of a pozzolanic concrete (CPZ10) and compared to ordinary concrete (OC). The tests of migration are made under an electric field, at different temperatures, from 5 to 50°C (41 to 122°F). Also, a study of the activation energy was made and compared with the Arrhenius theory. The test results showed that the migration coefficient of concrete increases with increasing temperature. The activation energy values of natural pozzolan incorporated concretes were lower than OC.
The degradation of reinforced concrete (RC) structures exposed to marine environments is largely due to the transfer of chloride ions through the material. The prediction of the penetration of these ions in the concrete by the diffusion coefficient is a fundamental indicator for the characterization of its durability. Tests simulating chloride diffusion in saturated areas are developed at a constant temperature; however, in reality, the temperature fluctuates with the seasons and diurnal variations. To simulate the coupled temperature diffusion of chloride in RC structures in permanent contact with the Mediterranean Sea, an experimental program was developed in the laboratory to assess the migration coefficients of a pozzolanic concrete (CPZ10) and compared to ordinary concrete (OC). The tests of migration are made under an electric field, at different temperatures, from 5 to 50°C (41 to 122°F). Also, a study of the activation energy was made and compared with the Arrhenius theory. The test results showed that the migration coefficient of concrete increases with increasing temperature. The activation energy values of natural pozzolan incorporated concretes were lower than OC.
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