A reactive transport model was employed to investigate the influence of multiple hydrate phases during acetic acid attack on Portland cement paste. The simulation accounted for the dissolution of primary cement hydrates like Ettringite, Portlandite and C-S-H, along with the formation of silica gel products impacting diffusivity. The simulations primarily utilized independent material parameters, though the effective specific surface area of C-S-H phases required adjustment, indicating that only a small fraction is active in bulk paste compared to experimental values obtained from powders. Experiments involved exposing hardened cement paste samples to acetic acid (pH = 3) for durations ranging from 35 to 84 days. The model predicted changes in mineral assemblages, porosity, and pore solution chemistry versus degradation depth and time. Comparison of calculated Ca and Si-contents with experimentally obtained values from μXRF analysis demonstrated good agreement of within 6% error, highlighting the importance of considering multiple minerals.

中文翻译：

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硅酸盐水泥浆中乙酸诱导降解的反应性传输模型


采用反应性传输模型研究乙酸侵蚀过程中多个水合物相对波特兰水泥浆的影响。该模拟考虑了 Ettringite、Portlandite 和 CSH 等原生水泥水合物的溶解，以及影响扩散率的硅胶产品的形成。模拟主要利用独立的材料参数，尽管 CSH 相的有效比表面积需要调整，这表明与从粉末中获得的实验值相比，块状糊状物中只有一小部分是活性的。实验包括将硬化水泥浆样品暴露于乙酸 （pH = 3） 中 35 至 84 天。该模型预测了矿物组合、孔隙率和孔隙溶液化学性质随降解深度和时间的变化。将计算出的 Ca 和 Si 含量与 μXRF 分析的实验值进行比较，结果表明误差在 6% 以内，具有良好的一致性，突出了考虑多种矿物的重要性。