Freezing of partially saturated air-entrained concrete: A multiphase description of the hygro-thermo-mechanical behaviour
Freezing of partially saturated air-entrained concrete: A multiphase description of the hygro-thermo-mechanical behaviour
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DOI：
10.1016/j.ijsolstr.2018.07.004
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发表时间：
2018-11-01
影响因子：
3.6
通讯作者：
Ansell, Anders
中科院分区：
文献类型：
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作者：
Eriksson, Daniel;Gasch, Tobias;Ansell, Anders
尽管加气混凝土通常用于位于寒冷气候、暴露在潮湿环境中的混凝土结构，但在检查过程中经常发现冻害。然而，通常很难评估损害的程度和严重性。因此，需要更好的工具和辅助手段来补充已经建立的评估方法。多项研究已成功表明，基于孔隙力学和多相方法的模型可用于描述加气混凝土的冻结行为。然而，这些模型通常仅限于空气孔隙系统的规模。因此，很难在涉及真实结构的应用中使用。本研究提出了一种湿热机械多相模型，该模型描述了结构尺度上部分饱和加气混凝土的冻结行为。该模型以通用有限元代码实现，并提供了两个数值示例来验证和显示该模型的功能。第一个涉及加气水泥浆体的一系列实验测试，而第二个旨在展示模型解释水分初始不均匀分布的能力。虽然模型预测低估了测量应变的大小，但结果仍然表明该模型可以捕捉结构尺度实验测试中观察到的一般冻结行为。此外，结果表明该模型能够描述由不均匀湿度分布引起的冻结引起的变形。 (C) 2018 Elsevier Ltd. 保留所有权利。
Even though air-entrained concrete is usually used for concrete structures located in cold climates that are exposed to wet environments, frost damage is frequently detected during inspections. However, it is often hard to assess the extent and severity of the damage and. thus, there is a need for better tools and aids that can complement already established assessment methods. Several studies have successfully shown that models based on poromechanics and a multiphase approach can be used to describe the freezing behaviour of air-entrained concrete. However, these models are often limited to the scale of the air pore system arid. hence, hard to use in applications involving real structures. This study proposes a hygro-thermo-mechanical multiphase model which describes the freezing behaviour of partially saturated air-entrained concrete on the structural scale. The model is implemented in a general FE-code and two numerical examples are presented to validate and show the capabilities of the model. The first concerns a series of experimental tests of air-entrained cement pastes, whereas the second aims to show the capability of the model to account for an initial non-uniform distribution of moisture. While the model predictions underestimate the magnitude of the measured strains, the results still show that the model can capture the general freezing behaviour observed in the experimental tests on the structural scale. Furthermore, the results demonstrate that the model is capable of describing freezing induced deformations caused by non-uniform moisture distributions. (C) 2018 Elsevier Ltd. All rights reserved.