骨料粒径对混凝土劈拉性能及尺寸效应影响的细观数值研究

发布时间：2018-03-21 06:59

本文选题：混凝土　切入点：劈裂抗拉强度　出处：《工程力学》2017年09期 　论文类型：期刊论文

【摘要】：混凝土材料宏观力学行为的非线性及尺寸效应根源于其内部组成的非均质性。考虑材料细观结构非均质性的影响,建立由骨料颗粒、砂浆基质和界面过渡区组成的混凝土细观尺度力学模型。对尺寸为150 mm、250 mm、350 mm和450 mm的混凝土立方体模型劈裂抗拉破坏行为进行细观数值模拟,探讨骨料粒径(最大粒径分别为:10 mm、20 mm、30 mm和40 mm)的影响机制,并与试验结果进行对比分析。结果表明:1)混凝土材料的劈裂抗拉强度随着骨料粒径增大而略微降低,最大骨料粒径达到30 mm左右时,强度降低趋势变缓;2)四种骨料粒径下混凝土立方体劈裂抗拉强度均存在尺寸效应现象,相比于大骨料试件,小骨料试件的破坏更具脆性,因而其尺寸效应更显著;3)混凝土劈裂抗拉强度尺寸效应行为与Ba?ant和Weibull提出的尺寸效应理论相吻合。
[Abstract]:The nonlinearity and size effect of macroscopic mechanical behavior of concrete materials are rooted in the heterogeneity of internal composition. A mesoscale mechanical model of concrete composed of mortar matrix and interfacial transition zone. The crack and tensile failure behavior of the concrete cube model with the dimensions of 150 mm ~ 250 mm ~ 350 mm and 450 mm is simulated. The influence mechanism of aggregate particle size (the maximum particle size is: 10 mm / 20 mm ~ 30 mm and 40 mm) is discussed and compared with the experimental results. The results show that the splitting tensile strength of concrete material decreases slightly with the increase of aggregate particle size. When the maximum aggregate size is about 30 mm, the decreasing trend of strength decreases slowly. (2) the cube splitting tensile strength of concrete under four kinds of aggregate particle size has the phenomenon of size effect. Compared with the large aggregate specimen, the failure of small aggregate specimen is more brittle. As a result, the size effect of the concrete is more significant than that of the concrete. (3) the size effect behavior of the splitting tensile strength of concrete and the effect of Ba3? The size effect theory proposed by ant and Weibull is consistent.
【作者单位】：北京工业大学城市减灾与防灾防护教育部重点实验室;防灾科技学院防灾工程系;
【基金】：国家自然科学基金创新研究群体项目(51421005);国家自然科学基金项目(51408127) 教育部创新团队项目(IRT13044)
【分类号】：TU528

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