This study established a new transport model by using the COMSOL-IPHREEQC interface to simulate the changes in the morphology of hydrated cement paste due to the diffusion of carbon dioxide and chloride ion. A series of constitutive models such as the cement hydration model (to compute the dissolution rate of each clinker mineral), thermodynamic model (to perform the hydration reaction, reaction due to transport of ions, chemical and physical adsorption of chloride ion during the chloride ion ingression and dissolution rate of calcium-silica-hydrate (C–S–H) simultaneously with portlandite for the carbonation), porosity determination, and COMSOL Multiphysics (for the calculation of transport problems) were integrated using MATLAB language to determine the pore solution chemistry, hydrates assemblage, and porosity of the cement paste exposed to aggressive environments. During the diffusion of carbon dioxide gas, the decalcification of C–S–H was realistically considered by assuming that the Ca/Si ratio of C–S–H decreased from 1.67 (Jennite type C–S–H) to 0.67 (Tobermorite C–S–H), and then from 0.67 to 0 (silica gel). The proposed integrated platform was well verified with different sets of reported and raw experimental results and existing models, indicating a realistic predictability for chloride ion ingression and carbonation. The developed model discloses the effect of coupling the progression of hydration with reaction due to the transport of ions by using the free chloride ion profile and phase assemblages during the chloride ion ingression.

本研究利用 COMSOL-IPHREEQC 接口建立了新的输运模型，模拟二氧化碳和氯离子扩散引起的水化水泥浆体形态变化。一系列本构模型，如水泥水化模型（计算每种熟料矿物的溶解速率）、热力学模型（进行水化反应、离子传输反应、氯离子在氯离子过程中的化学和物理吸附）使用 MATLAB 语言集成硅钙水合物 ( C –S–H) 的侵入和溶解速率以及用于碳酸化的硅酸钙石）、孔隙率测定和 COMSOL Multiphysics（用于计算输运问题），以确定孔隙溶液化学性质、水合物组合以及暴露于侵蚀性环境的水泥浆体的孔隙率。在二氧化碳气体扩散过程中，通过假设C –S–H 的Ca /Si 比从 1.67（Jennite 型C –S–H）下降到 0.67（托贝莫来石C ），实际考虑了 C –S–H 的脱钙。 –S–H)，然后从 0.67 到 0（硅胶）。所提出的集成平台得到了不同组报告和原始实验结果以及现有模型的良好验证，表明氯离子侵入和碳酸化的现实可预测性。所开发的模型揭示了通过使用氯离子侵入期间的游离氯离子分布和相组合，由于离子传输而将水合进程与反应耦合的效果。