In this paper, we are studying the shrinkage and microstructural damages induced by drying in samples exposed to drying at very early ages. We measure for two model mortars the average and local shrinkage through microtomography images subtraction along with microstructure evolution through microtomography radiographs. Our measurements showcase the role played by the kinetics of propagation of drying-induced capillary stresses on shrinkage distribution. They moreover show the existence of two distinct types of microstructural damages in such exposed samples occurring at the onset of the sample desaturation after a period as short as a couple of hours. Our analysis allows for a first-order understanding of the scaling of the main stress, length and time scales of the problem with some material parameters such as compressibility and permeability. We finally extrapolate and discuss the consequences of the above features on standard concrete casting and on concrete 3D printing.

中文翻译：

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暴露在外的新鲜水泥基材料在早期因干燥引起的损坏：从标准铸造到 3D 打印


在本文中，我们正在研究早期干燥的样品因干燥而引起的收缩和微观结构损伤。我们通过显微断层扫描图像减法测量两种模型迫击炮的平均和局部收缩率，并通过显微断层扫描射线照片测量微观结构的演变。我们的测量展示了干燥引起的毛细管应力传播动力学对收缩分布的影响。此外，他们还表明，在短至几个小时后样品去饱和开始时，此类暴露的样品中存在两种不同类型的微观结构损伤。我们的分析可以对问题的主应力、长度和时间尺度与某些材料参数（例如压缩率和渗透率）的缩放有初步的了解。最后，我们推断并讨论上述特征对标准混凝土铸造和混凝土 3D 打印的影响。