Abstract A multi-scale micromechanics model is proposed to describe the expansion and deterioration of concrete due to Alkali-Silica Reaction (ASR). The mechanics of ASR induced deterioration of a Representative Elementary Volume (REV) of concrete is modeled through a synthesis of distributed microcracking and mean-field homogenization. At the microscale, ASR-gel-pressure induced microcrack growth in and around the reactive aggregates is modeled using the framework of linear elastic fracture mechanics. Mean-field homogenization across multiple scales is used to obtain the overall expansion and degradation of the material. By specifying the spatial distribution of the pressurizing gel, two different ASR mechanisms associated with “slowly” and “rapidly” reactive aggregates can be modeled. Experimental data for concrete degradation as a function of the macroscopic expansion is found to lie within the theoretical upper and lower bounds that characterize the distribution of the gel in the aggregate or the cement paste.

中文翻译：

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ASR 引起的混凝土膨胀和劣化：微观力学建模和分析

摘要 提出了一种多尺度微观力学模型来描述由于碱硅反应（ASR）引起的混凝土膨胀和劣化。ASR 引起的混凝土代表性基本体积 (REV) 退化的力学通过分布式微裂纹和平均场均质化的综合进行建模。在微观尺度上，使用线弹性断裂力学的框架对反应性聚集体内部和周围的 ASR 凝胶压力诱导的微裂纹生长进行建模。跨多个尺度的平均场均化用于获得材料的整体膨胀和降解。通过指定加压凝胶的空间分布，可以模拟与“缓慢”和“快速”反应聚集体相关的两种不同的 ASR 机制。