细观层面的混凝土碳化过程数值模拟

Numerical Simulation of Concrete Carbonation Process on Meso scale

摘要:

为在细观层面上研究混凝土碳化问题，首先建立了基于积累分布函数的三维球形骨料生成方法，分析了随机性对模拟结果的影响，对骨料最大粒径、最小粒径和体积分数的选取原则进行了讨论.建立了简化的混凝土碳化数值模型，分析了骨料对宏观层面混凝土碳化行为的影响.结果表明，骨料的稀释效应和扭曲效应将降低混凝土的碳化深度；骨料在水泥浆中的非均匀分布将导致宏观上混凝土碳化深度的非均匀性.

Abstract:

In order to study the problem of concrete carbonation on meso scale, a 3D spherical aggregate generation method based on the cumulative distribution function (CDF) is established. The influence of randomness in this method on the simulation results is analyzed. The principle of how to determine the parameters such as maximum diameters, minimum diameters and volume fraction of aggregate is discussed as well. Based on the previous method, a simplified numerical model of concrete carbonation is further proposed. The influence of aggregates on the concrete carbonation process on macro scale is analyzed. The results show that the dilute effect and tortuosity effect caused by aggregate can decrease the concrete carbonation depth. Besides, the nonuniform distribution of aggregates in cement paste will result in the inhomogeneity of concrete carbonation depth on macro scale.