Fullerenes, Nanotubes and Carbon Nanostructures ( IF 2.3 ) Pub Date : 2021-10-04 , DOI: 10.1080/1536383x.2021.1986485 Anming She 1, 2 , Kun Ma 1 , Wu Yao 1, 2 , Junqing Zuo 3 , Gang Liao 1
Abstract
The Krstulovic-Dabic (KD) hydration kinetic model is often used to study the hydration mechanism of cement-based materials. Based on this model, isothermal calorimetry is usually to study the hydration kinetics of cementitious materials, and the obtained data can describe the hydration process well. In this paper, low-field NMR was used to monitor the hydration process of cementitious materials, and the results were compared with that obtained by isothermal calorimetry. The results showed that KD model was also suitable for Low-field NMR. And the results of the low-field NMR were consistent with those of the isothermal calorimetry, both proving that the hydration stages of the PC and C3S were NG-I-D and NG-D, respectively. The difference was that low-field NMR displayed a faster hydration rate than isothermal calorimetry, which led to a shorter duration of D process. This phenomenon may be due to the fact that low-field NMR (1H in free water) and isothermal calorimetry (hydration heat) are based on different signal sources, and the water consumption rate is faster than heat variation rate in the early hydration period. In summary, low-field exhibits high effectiveness in characterizing the hydration kinetic process of cementitious materials.
中文翻译:
基于低场核磁共振和等温量热法的胶凝材料水化动力学
摘要
Krstulovic-Dabic (KD) 水化动力学模型常用于研究水泥基材料的水化机理。基于该模型,等温量热法通常用于研究胶凝材料的水化动力学,得到的数据可以很好地描述水化过程。本文采用低场核磁共振技术监测胶凝材料的水化过程,并与等温量热法的结果进行了对比。结果表明KD模型也适用于低场核磁共振。并且低场核磁共振的结果与等温量热法的结果一致,都证明了PC和C 3的水化阶段S 分别是 NG-ID 和 NG-D。不同之处在于,低场核磁共振比等温量热法显示出更快的水合速率,这导致 D 过程的持续时间更短。这种现象可能是由于低场核磁共振(游离水中的1 H)和等温量热法(水化热)基于不同的信号源,水化初期耗水率快于热变化率. 总之,低场在表征胶凝材料的水化动力学过程中表现出很高的有效性。