Abstract Spalling, which is a phenomenon encountered when high-performance concrete is exposed to high temperature, can lead to large economical damage and can be a major safety hazard. Moisture distribution in concrete during exposure to fire is of paramount importance for understanding the complex mechanism of this phenomenon. To capture in its fullness this mechanism, it is crucial to account for the heterogeneous nature of concrete. In this paper, the first 3D analysis of moisture distribution in concrete at high temperature through in-situ neutron tomography is presented. The world-leading flux at the Institute Laue Langevin in Grenoble, France allowed capturing one 3D scan per minute, which is sufficient to follow the fast dehydration process. The paper describes the experimental setup with the heating system and discusses in detail the framework of the neutron tomography test. Quantitative analysis showing the effect of the aggregate size on the moisture distribution is presented.

中文翻译：

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原位中子层析成像分析高温混凝土中的水分迁移

摘要 剥落是高性能混凝土暴露于高温时遇到的一种现象，会导致巨大的经济损失，并可能成为主要的安全隐患。暴露在火灾中的混凝土中的水分分布对于理解这种现象的复杂机制至关重要。为了完整地捕捉这种机制，重要的是要考虑混凝土的异质性。在本文中，首次通过原位中子断层扫描对高温混凝土中的水分分布进行了 3D 分析。法国格勒诺布尔劳厄朗之万研究所的世界领先通量允许每分钟捕获一次 3D 扫描，这足以跟踪快速脱水过程。本文描述了带有加热系统的实验装置，并详细讨论了中子断层扫描测试的框架。定量分析显示了骨料尺寸对水分分布的影响。