This paper reports the influence of submicron hydrophilic fibers on the hydration and microstructure of Portland cement paste. Submicron fibrillated cellulose (SMC) fibers was prepared by the acid hydrolysis of cotton fibers in H₂SO₄ solution (55% v/v) for 1.5 h at a temperature of 50 °C. The SMC fibers were added into cement with a dosage of 0.03 wt. %, and the effect of SMC on the hydration and microstructure of cement paste was investigated by calorimeter analysis, XRD, FT-IR, DSC-TG, and SEM. Microcrystalline cellulose (MCC) fibers were used as the contrast admixture with the same dosage in this study. The results show that the addition of SMC fibers can accelerate the cement hydration rate during the first 20 h of the hydration process and improve the hydration process of cement paste in later stages. These results are because the scale of SMC fibers more closely matches the size of the C-S-H gel compared to MCC fibers, given that the primary role of the SMC is to provide potential heterogeneous nucleation sites for the hydration products, which is conducive to an accelerated and continuous hydration reaction. Furthermore, the induction and bridging effects of the SMC fibers make the cement paste microstructure more homogeneous and compact.

中文翻译：

---

棉花亚微米原纤化纤维素纤维对硅酸盐水泥浆体水化和微观结构的影响


本文报道了亚微米亲水纤维对波特兰水泥浆体水化和微观结构的影响。亚微米原纤化纤维素(SMC)纤维是通过将棉纤维在H ₂ SO ₄溶液(55% v / v )中在50℃的温度下酸解1.5h来制备的。将SMC纤维添加到水泥中，用量为0.03wt. %，并通过量热分析、XRD、FT-IR、DSC-TG和SEM研究了SMC对水泥浆体水化和微观结构的影响。本研究使用微晶纤维素（MCC）纤维作为相同剂量的对比混合物。结果表明，SMC纤维的加入可以加快水泥水化过程前20 h的水化速度，并改善后期水泥浆体的水化过程。这些结果是因为与 MCC 纤维相比，SMC 纤维的尺寸与 CSH 凝胶的尺寸更接近，因为 SMC 的主要作用是为水化产物提供潜在的异质成核位点，这有利于加速和连续水合反应。此外，SMC纤维的诱导和架桥作用使水泥浆体的微观结构更加均匀和致密。