基于三维微-细观尺度模型的混凝土力学性能研究

依据水泥种类、水灰比、配合比和骨料级配等信息，在微观尺度上引入CEMHYD3D水化模型重构了水泥浆模型、在细观尺度上发展硬核/软壳模型构建了混凝土模型；研究基于Rankine准则和损伤模型的适用于混凝土微-细观模型的数值均匀化方法，从而提出混凝土力学性能递进分析和预测方法。算例分析表明，提出的方法能够较好地分析和预测混凝土的宏观力学性能；通过老化病害过程微观尺度的模拟，可实现混凝土老化病害机理分析。

Mechanical properties of concrete based on 3D micro-meso scale numerical models

According to the special cement type, water-to-cement ratio, mix proportion, and particle size distribution of aggregates, the CEMHYD3D hydration model was used to rebuild the representative volume element(RVE)model of a microstructure(cement)based on the micro scale, and the hard core/soft shell model was developed to build the RVE model of the mesostructure based on the meso scale. Then, numerical homogenization methods based on the Rankine criterion and the damage model, which are respectively suitable for mico and meso scales, were studied. Hierarchical analysis and prediction methods for concrete mechanical properties are proposed. The results of an example show that the proposed method can satisfactorily analyze and predict the macro mechanical properties of concrete. The developed reconstruction microstructure method can also be used to explore the aging and degradation mechanisms for concrete with simulations of physical and chemical processes at a micro scale.