Advances in nano-computed X-ray tomography (nCT), nano X-ray fluorescence spectrometry (nXRF), and high-performance computing have enabled the first direct comparison between observations of three-dimensional nanoscale microstructure evolution during cement hydration and computer simulations of the same microstructure, using HydratiCA. nCT observations of a collection of triclinic tricalcium silicate () particles reacting in a calcium hydroxide solution are reported and compared to simulations that duplicate, as nearly as possible, the thermal and chemical conditions of those experiments. Particular points of comparison are the time dependence of the solid phase volume fractions, spatial distributions, and morphologies. Comparisons made at 7 hours of reaction indicate that the simulated and observed volumes of consumed by hydration agree to within the measurement uncertainty. The location of simulated hydration product is qualitatively consistent with the observations, but the outer envelope of hydration product observed by nCT encloses more than twice the volume of hydration product in the simulations at the same time. Simultaneous nXRF measurements of the same observation volume imply calcium and silicon concentrations within the observed hydration product envelope that are consistent with Ca(OH)₂ embedded in a sparse network of calcium silicate hydrate (C–S–H) that contains about 70% occluded porosity in addition to the amount usually accounted as gel porosity. An anomalously large volume of Ca(OH)₂ near the particles is observed both in the experiments and in the simulations, and can be explained as originating from the hydration of additional particles outside the field of view. Possible origins of the unusually large amount of observed occluded porosity are discussed.

中文翻译：

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硅酸三钙水化的3D实验和模拟的关键比较

纳米计算机X射线断层扫描（nCT），纳米X射线荧光光谱法（nXRF）和高性能计算的进步，使水泥水化过程中三维纳米尺度微观结构演变的观测结果与计算机模拟的首次直接比较成为可能。使用HydratiCA具有相同的微观结构。报道了在氢氧化钙溶液中反应的三斜晶硅酸三钙（n ）颗粒的nCT观察结果，并将其与模拟进行了比较，这些模拟尽可能地复制了这些实验的热和化学条件。比较的特殊点是固相体积分数，空间分布和形态的时间依赖性。在反应7小时后进行的比较表明，模拟和观察到的水合消耗的水在测量不确定度内是一致的。从本质上讲，模拟水合产物的位置与观测值一致，但是通过nCT观察到的水合产物的外部包膜同时包围了模拟中水合产物的两倍以上的体积。相同观测体积的同时nXRF测量表明，观测到的水合产物包络线中的钙和硅浓度与嵌入稀疏的硅酸钙水合物（C–S–H）网络中的Ca（OH）₂一致，其中约70％的闭塞了除孔隙率外，通常将其视为凝胶孔隙率。异常大量的Ca（OH）₂在实验和模拟中都观察到了颗粒附近，并且可以将其解释为源自视场外其他颗粒的水合作用。讨论了异常大量观察到的闭塞孔隙的可能成因。