Fang Yunhui, Zhang Xiaofang, Yan Dongming, Lin Zhijun, Ma Xiuxing, Lai Junying, Liu Yi, Ke Yuliang, Chen Zhanhua, Wang Zhaopeng
Polytechnic Institute, Zhejiang University, Hangzhou 310015, China.
College of Civil Engineering and Architecture, Zhejiang University, Hangzhou 310058, China.
Materials (Basel). 2023 Jun 2;16(11):4168. doi: 10.3390/ma16114168.
To investigate the effects of Reference cement (RC) and Belite cement (LC) systems, different molecular structures of polycarboxylate ether (PCE) were prepared through the free radical polymerization reaction and designated as PC-1 and PC-2. The PCE was characterized and tested using a particle charge detector, gel permeation chromatography, a rotational rheometer, a total organic carbon analyzer, and scanning electron microscopy. The results showed that compared to PC-2, PC-1 exhibited higher charge density and better molecular structure extension, with smaller side-chain molecular weight and molecular volume. PC-1 demonstrated enhanced adsorption capacity in cement, improved initial dispersibility of cement slurry, and a reduction in slurry yield stress of more than 27.8%. LC, with its higher CS content and smaller specific surface area compared to RC, could decrease the formation of flocculated structures, resulting in a reduction in slurry yield stress of over 57.5% and displaying favorable fluidity in cement slurry. PC-1 had a greater retarding effect on the hydration induction period of cement compared to PC-2. RC, which had a higher CS content, could adsorb more PCE, leading to a greater retarding effect on the hydration induction period compared to LC. LC and PC-2, on the other hand, exhibited inhibition during the hydration acceleration period. The addition of PCE with different structures did not significantly affect the morphology of hydration products in the later stage, which was consistent with the trend of K variation. This indicates that the analysis of hydration kinetics can better reflect the final hydration morphology.
为研究基准水泥（RC）和贝利特水泥（LC）体系的影响，通过自由基聚合反应制备了不同分子结构的聚羧酸醚（PCE），分别命名为PC - 1和PC - 2。使用颗粒电荷检测器、凝胶渗透色谱仪、旋转流变仪、总有机碳分析仪和扫描电子显微镜对PCE进行了表征和测试。结果表明，与PC - 2相比，PC - 1表现出更高的电荷密度和更好的分子结构伸展性，其侧链分子量和分子体积更小。PC - 1在水泥中的吸附能力增强，水泥浆的初始分散性提高，浆体屈服应力降低超过27.8%。与RC相比，LC的C₃S含量更高且比表面积更小，可减少絮凝结构的形成，导致浆体屈服应力降低超过57.5%，且在水泥浆中表现出良好的流动性。与PC - 2相比，PC - 1对水泥水化诱导期的缓凝作用更强。C₃S含量更高的RC可吸附更多的PCE，因此与LC相比，其对水化诱导期的缓凝作用更大。另一方面，LC和PC - 2在水化加速期表现出抑制作用。添加不同结构的PCE对后期水化产物的形貌没有显著影响，这与K变化趋势一致。这表明水化动力学分析能更好地反映最终的水化形貌。
