| 1. |
- Jin, Hesong, et al.
(författare)
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Iodide and chloride ions diffusivity, pore characterization and microstructures of concrete incorporating ground granulated blast furnace slag
- 2022
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Ingår i: Journal of Materials Research and Technology. - : Elsevier BV. - 2238-7854. ; 16, s. 302-321
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Tidskriftsartikel (refereegranskat)abstract
- Innovative approaches are under research to study the resistance of chloride ion penetration in concrete containing chloride ions, to minimize the impact of chloride ion penetration test errors in coastal reinforced concrete (RC), which is helpful to the design of coastal RC structures. In this study, the diffusion depth, free ion concentration and diffusion coefficient of chloride, iodide ions with different curing ages and GGBFS content were measured by the Rapid Chloride Migration Test (RCM) and Rapid Iodide Migration tests (RIM). The SEM-EDS and MIP were used to analyze the microstructures, pore size distribution and the hydrated products. The results show that the performance of GGBFS concrete against the diffusion of corrosive ions is affected by the curing age and the content of GGBFS. With the increase of GGBFS content, especially concrete with 60% GGBFS, the influence of chloride, iodide ion penetrating into concrete gradually becomes smaller. The long-age curing system is more conducive to the concrete resistance to the migration and diffusion of chloride, iodine ions. Compared with the ordinary concrete, the total porosity of concrete mixed with GGBFS is lower, the internal microstructures have fewer cracks and defects, the density is better, and the diffusion coefficient of chloride and iodide ions is also lower. In addition, using the concept of corrosive ion adjustment coefficient (conversion coefficient of diffusion between chloride ion and iodide ion) and applying the data regression analysis (DRA), it is found that there is a good quadratic parabolic function relationship between the GGBFS content and the ions adjustment coefficient.
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| 2. |
- Liu, Jun, et al.
(författare)
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Electrically driven ionic transport in the RCM and RIM: Investigations based on experiments and numerical simulations
- 2022
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Ingår i: Construction and Building Materials. - : Elsevier BV. - 0950-0618. ; 331
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Tidskriftsartikel (refereegranskat)abstract
- In this work, the rapid chloride migration test (RCM) and the rapid iodide migration test (RIM) were utilized to investigate ionic transport in concrete with the aid of an externally applied electric field. Unlike most existing work, this study establishes computational models of ionic transport in chloride-contaminated and chloride-free concrete. The model is validated by the consistency between the numerical and experimental chloride profiles. It is found that the chloride migration depth in the RCM test is obviously affected, and the results for chloride-contaminated concrete are 50% larger compared with those for chloride-free concrete. However, the difference between the two kinds of concretes is only 5% when measured using the RIM test. Thus, the results of the RIM test are more accurate and provide a better choice for applications to characterization of chloride-contaminated concrete.
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