Moisture diffusion influences the durability and long-term performance of concrete and whilst it predominantly occurs via the cement matrix and Interfacial Transition Zone, most existing models consider concrete to be homogeneous. This paper introduces a novel micro-meso model that employs random packing and Voronoi tessellation. Rayleigh-Ritz pore distribution and Brunauer-Skalny-Bodor models are combined to determine the radius and fraction of various pores. The results indicate that relative humidity diffuses faster with increasing temperature, decreasing ambient relative humidity and tortuosity. Ambient relative humidity has a greater influence on diffusion compared to temperature and tortuosity. Numerical and experimental comparisons demonstrate that the proposed methodology effectively captures relative humidity distribution across various scenarios. Furthermore, explicit pore network modelling incorporates key parameters for a more accurate analysis. Integrating the proposed methodology into a fully coupled hygro-mechanical framework can potentially yield more accurate predictions of mechanical behaviour; enhancing the reliability of long-term performance assessments and enabling more durable concrete design.

中文翻译：

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一种用于混凝土中水分扩散中尺度建模的创新方法


水分扩散会影响混凝土的耐久性和长期性能，虽然它主要通过水泥基体和界面过渡区发生，但大多数现有模型认为混凝土是均匀的。本文介绍了一种采用随机堆积和 Voronoi 镶嵌的新型微细观模型。将 Rayleigh-Ritz 孔分布和 Brunauer-Skalny-Bodor 模型相结合，以确定各种孔的半径和分数。结果表明，相对湿度随着温度的升高而扩散得更快，环境相对湿度和弯曲度降低。与温度和迂曲度相比，环境相对湿度对扩散的影响更大。数值和实验比较表明，所提出的方法有效地捕获了各种情况下的相对湿度分布。此外，显式孔隙网络建模结合了关键参数，以实现更准确的分析。将所提出的方法集成到完全耦合的湿机械框架中可能会产生更准确的机械行为预测;提高长期性能评估的可靠性，实现更耐用的混凝土设计。