Multiscale hydro-thermo-chemo-mechanical coupling: Application to alkali–silica reaction
Multiscale hydro-thermo-chemo-mechanical coupling: Application to alkali–silica reaction
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DOI：
10.1016/j.commatsci.2013.12.029
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发表时间：
2014-03
影响因子：
3.3
通讯作者：
Tao Wu;I. Temizer;P. Wriggers
中科院分区：
文献类型：
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作者：
Tao Wu;I. Temizer;P. Wriggers
碱-硅反应（ASR）是一个影响混凝土结构的复杂化学过程，到目前为止，已经提出了各种机制来解释材料水平上的反应。本研究采用了一种简单的机制，即反应发生在混凝土的微孔处，旨在建立一个多尺度框架来分析混凝土中ASR引起的破坏。为此，硬化水泥浆体（HCP）和嵌入均质水泥浆体基质中的随机分布骨料的三维微ct扫描分别代表混凝土的微观尺度和中观尺度。从HCP的微观尺度开始，分析了ASR引起的变质与化学反应程度的关系。温度和相对湿度影响化学程度。通过计算均质化方法获得ASR有效损伤与化学程度之间的相关性，从而建立起微观尺度损伤与宏观尺度破坏之间的桥梁。建立了基于交错法的混凝土中尺度三维水-热-化学-力学模型，该模型能够反映ASR引起的微尺度劣化。
Alkali–Silica Reaction (ASR) is a complex chemical process that affects concrete structures and so far various mechanisms to account for the reaction at the material level have already been proposed. The present work adopts a simple mechanism, in which the reaction takes place at the micropores of concrete, with the aim of establishing a multiscale framework to analyze the ASR induced failure in the concrete. For this purpose, 3D micro-CT scans of hardened cement paste (HCP) and aggregates with a random distribution embedded in a homogenized cement paste matrix represent, respectively, the microscale and mesoscale of concrete. The analysis of the deterioration induced by ASR with the extent of the chemical reaction is initialized at the microscale of HCP. The temperature and the relative humidity influence the chemical extent. The correlation between the effective damage due to ASR and the chemical extent is obtained through a computational homogenization approach, enabling to build the bridge between microscale damage and macroscale failure. A 3D hydro-thermo-chemo-mechanical model based on a staggered method is developed at the mesoscale of concrete, which is able to reflect the deterioration at the microscale due to ASR.