Schade Tim, Middendorf Bernhard
Department of Structural Materials and Construction Chemistry, University of Kassel, 34125 Kassel, Germany.
Materials (Basel). 2021 Sep 25;14(19):5573. doi: 10.3390/ma14195573.
This paper presents a model to calculate the sulphate agent amount and sulphate agent ratio for fine grounded and fast hardening Portland cement clinker. Despite sufficient knowledge about the influence of calcium sulphate on the hydration process of cement, the sulphate agent amount is mostly adjusted empirically. As a result, often a wide and unfeasible experimental matrix has to be tested. In this work, Design of Experiments (DoE) was used in combination with in-situ X-ray diffraction (XRD) tests to accurately adjust the sulphate agent of different finely ground cement by calculation. With only 42 tests, it was possible to analyse in total the influence of the sulphate agent, the grinding fineness and the use of C-S-H-seeds for the use in fast-hardening Portland cement-based systems. In addition, it was found that a hemihydrate to anhydrite content of 25/75 leads to a stabilisation of the hydrated system in the first 24 h of hydration. A model for the optimisation of the sulphate agent composition in dependency of the cement fineness could be determined. Furthermore, it was shown that the DoE also provides optimal results in material sciences in a resource-saving way.
本文提出了一种计算细磨快硬波特兰水泥熟料中硫酸盐外加剂用量和硫酸盐外加剂比例的模型。尽管对硫酸钙对水泥水化过程的影响已有足够了解，但硫酸盐外加剂的用量大多是凭经验调整的。因此，常常需要测试一个宽泛且不可行的实验矩阵。在这项工作中，实验设计（DoE）与原位X射线衍射（XRD）测试相结合，通过计算准确调整不同细磨水泥的硫酸盐外加剂。仅通过42次测试，就能够全面分析硫酸盐外加剂、粉磨细度以及使用C-S-H晶种对快硬波特兰水泥基体系的影响。此外，发现半水石膏与硬石膏含量为25/75时，可使水化体系在水化的前24小时内保持稳定。可以确定一个根据水泥细度优化硫酸盐外加剂组成的模型。此外，结果表明实验设计还能以节省资源的方式在材料科学中提供最佳结果。
