Jasielec Jerzy J, Stec Jakub, Szyszkiewicz-Warzecha Krzysztof, Łagosz Artur, Deja Jan, Lewenstam Andrzej, Filipek Robert
Faculty of Materials Science and Ceramics, AGH University of Science and Technology, Al. Mickiewicza 30, 30-059 Krakow, Poland.
Materials (Basel). 2020 Dec 3;13(23):5522. doi: 10.3390/ma13235522.
A non-equilibrium diffusion-reaction model is proposed to describe chloride transport and binding in cementitious materials. A numerical solution for this non-linear transport with reaction problem is obtained using the finite element method. The effective chloride diffusion coefficients and parameters of the chloride binding are determined using the inverse method based on a diffusion-reaction model and experimentally measured chloride concentrations. The investigations are performed for two significantly different cements: ordinary Portland and blast furnace cements. The results are compared with the classical diffusion model and appropriate apparent diffusion coefficients. The role of chloride binding, with respect to the different binding isotherms applied, in the overall transport of chlorides is discussed, along with the applicability of the two models. The proposed work allows the determination of important parameters that influence the longevity of concrete structures. The developed methodology can be extended to include more ions, electrostatic interactions, and activity coefficients for even more accurate estimation of the longevity.
提出了一种非平衡扩散-反应模型来描述水泥基材料中氯离子的传输和结合。利用有限元方法得到了该非线性传输与反应问题的数值解。基于扩散-反应模型和实验测量的氯离子浓度，采用反演方法确定了有效氯离子扩散系数和氯离子结合参数。对两种显著不同的水泥（普通硅酸盐水泥和高炉水泥）进行了研究。将结果与经典扩散模型和适当的表观扩散系数进行了比较。讨论了在应用不同结合等温线时，氯离子结合在氯离子整体传输中的作用，以及两种模型的适用性。所提出的工作可以确定影响混凝土结构耐久性的重要参数。所开发的方法可以扩展到包括更多离子、静电相互作用和活度系数，以便更准确地估计耐久性。
