Expansion and deterioration of concrete due to ASR: Micromechanical modeling and analysis
Expansion and deterioration of concrete due to ASR: Micromechanical modeling and analysis
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DOI：
10.1016/j.cemconres.2018.08.001
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发表时间：
2019-01-01
影响因子：
11.4
通讯作者：
Meschke, Guenther
中科院分区：
文献类型：
--
作者：
Iskhakov, Tagir;Timothy, Jithender J.;Meschke, Guenther
提出了一个多尺度细观力学模型来描述碱-硅酸反应(ASR)引起的混凝土膨胀和劣化。ASR引起混凝土典型基本体积(REV)劣化的机理是通过分布微裂缝和平均场均匀化的综合来模拟的。在微观尺度上，采用线弹性断裂力学框架模拟了ASR-凝胶压力诱导的微裂纹在活性骨料内部和周围的扩展。在多个尺度上的平均场均匀化被用来获得材料的整体膨胀和退化。通过指定加压凝胶的空间分布，可以模拟与“慢”和“快”反应聚集体相关的两种不同的ASR机制。随着宏观膨胀的作用，混凝土退化的实验数据被发现位于表征集料或水泥浆体中凝胶分布的理论上下限内。
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.