基于余能原理基面力元法的轻骨料混凝土骨料均匀性分析

Analysis of Aggregate Uniformity of Lightweight Aggregate Concrete Based on the Complementary Energy Principle and Base Force Element Method

摘要: 本文提出一种轻骨料混凝土骨料均匀度评价方法及相应的评价指标，并运用余能原理基面力元法建立轻骨料混凝土模型并进行细观损伤分析，同时探究轻骨料混凝土中骨料分散均匀性对轻骨料混凝土性能的影响。得到的结论为：基于余能原理基面力元法的轻骨料混凝土模型能够很好的进行轻骨料混凝土试件静态单轴受压以及受拉的模拟计算，同时清晰的展现了轻骨料混凝土试件加载后的损伤破坏过程。轻骨料混凝土试件轴心受压承载力受轻骨料分布均匀性影响较为明显，且均匀性指标值在1.6左右时，试件力学性能较好，当均匀性指标低于1.4时，轻骨料混凝土试件由于强度较弱的轻骨料相分散性较好试件整体的力学性能较差，而当大于1.6时随着数值增大试件中出现较多骨料聚集存在较多薄弱区域，试件的整体性能也在降低，同时轻骨料混凝土试件受压承载性能会随水灰比的增高明显降低。

Abstract: In this paper, an evaluation method of aggregate uniformity of lightweight aggregate concrete soil and corresponding evaluation indexes are proposed, and a model of lightweight aggregate concrete is established by using the residual energy principle based surface force element method to conduct mesoscopic damage analysis, and the influence of aggregate dispersion uniformity on the performance of lightweight aggregate concrete is explored. The conclusion is that the light aggregate concrete model based on the fundamental surface force element method of the complementary energy principle can well simulate the static uniaxial compression and tension of light aggregate concrete specimens, and clearly show the damage and failure process of light aggregate concrete specimens after loading. The axial compression capacity of light aggregate concrete specimens is significantly affected by the uniformity of distribution of light aggregate, and when the uniformity index value is about 1.6, the mechanical properties of the specimens are better; when the uniformity index is lower than 1.4, the mechanical properties of the specimens as a whole are worse because the light aggregate with weak strength has better phase dispersion. When the value is greater than 1.6, there are more weak areas of aggregate aggregation in the specimen, and the overall performance of the specimen is also decreased with the increase of the value. Meanwhile, the compression bearing performance of the light aggregate concrete specimen decreases significantly with the increase of the water-cement ratio.