Mesoscopic simulation method of concrete carbonation process
Mesoscopic simulation method of concrete carbonation process
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DOI：
10.1080/15732479.2011.605370
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发表时间：
2012-02
影响因子：
3.7
通讯作者：
X. Ruan;Z. Pan
中科院分区：
文献类型：
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作者：
X. Ruan;Z. Pan
大气中的混凝土结构可能遭受碳化过程引起的钢筋腐蚀问题。以往对混凝土碳化问题的研究大多是在宏观尺度上进行的。这些研究没有考虑团聚体的影响，这应该涉及到中尺度。为了将混凝土碳化问题的研究从宏观扩展到细观，提出了一种改进的混凝土随机骨料结构（RAS）模拟方法。该方法可分为两个步骤：三维模型的RAS过程和横截面的数值分析过程。在该方法中，分析了随机性对RAS结果的影响。基于质量守恒定律和化学反应动力学模型，建立了混凝土碳化的简化数值模型。讨论了模型中CO2有效扩散系数和碳酸化反应常数等关键参数的影响。并对混凝土碳化过程的宏、细观模拟进行了比较。最后介绍了该方法在实际工程中确定混凝土合理组成的应用。
Concrete structures in the atmosphere may suffer from the problem of steel corrosion induced by the carbonation process. Most of previous research on concrete carbonation problems has been performed on the macro-scale. These studies did not consider the influence of the aggregates, which should be involved on meso-scale. In order to extend the present studies on the problems of concrete carbonation from macro-scale to meso-scale, an improved method to simulate the random aggregate structure (RAS) in concrete has been proposed. This method can be divided into two steps: the process of RAS in a three-dimensional model, and the process of numerical analysis in a cross-section. In this method, the effect of the randomness on the results of RAS is analysed. Based on the mass conservation law and kinetic model of chemical reactions, a simplified numerical model of concrete carbonation is developed. The effect of the key parameters in this model such as effective diffusion coefficient of CO2 and carbonation reaction constant is discussed. The comparison of the simulations of concrete carbonation process on macro-scale and meso-scale is discussed as well. Finally, an application of the method to determine the proper composition of concrete in the practical engineering is presented.