Abstract The effect of increasing sulfate contents on the hydration of white cement was studied with a multi-technique approach. Quantitative X-Ray Diffraction (XRD) revealed that adding more gypsum in the cement resulted in more ettringite formation. Combining isothermal calorimetry, advanced in-situ 1H nuclear magnetic resonance (NMR) and early scanning electron microscopy (SEM) observations, it was possible to correlate the depletion of the gypsum with a change in C-S-H morphology, from needle-like to agglomerated C-S-H, together with a change in C-S-H gel pore content. Nevertheless, the content of C-S-H interlayer water remained similar and no change in C-S-H pore sizes were observed when increasing the sulfate content. The data allowed to calculate the volume composition of hydrated cement pastes at 3 days of hydration. The more gypsum was added to the cement, the lower was the bulk C-S-H volume due to lower gel pore content and the higher was the content of capillary porosity.

中文翻译：

---

硫酸盐对幼年 CSH 的影响

摘要 采用多技术方法研究了增加硫酸盐含量对白水泥水化的影响。定量 X 射线衍射 (XRD) 显示，在水泥中添加更多石膏会导致更多钙矾石形成。结合等温量热法、先进的原位 1H 核磁共振 (NMR) 和早期扫描电子显微镜 (SEM) 观察，有可能将石膏的消耗与 CSH 形态的变化相关联，从针状到凝聚的 CSH，连同 CSH 凝胶孔含量的变化。尽管如此，CSH 夹层水的含量保持相似，并且当增加硫酸盐含量时，没有观察到 CSH 孔径的变化。该数据允许计算水化 3 天时水化水泥浆体的体积组成。