A multi-level micromechanical model for elastic properties of hybrid fiber reinforced concrete
A multi-level micromechanical model for elastic properties of hybrid fiber reinforced concrete
复制标题
混合纤维混凝土弹性性能的多级微力学模型
DOI：
10.1016/j.conbuildmat.2017.07.024
复制
发表时间：
2017
影响因子：
7.4
通讯作者：
Chen Qing
中科院分区：
文献类型：
--
作者：
Zhang Yao;Yan Zhi-guo;Ju J. Woody;Zhu He-hua;Chen Qing
为了揭示和分析混杂纤维混凝土（HFRC）细观结构对宏观力学性能的影响，需要建立多尺度细观力学模型。本研究涉及提出一个多层次的微观力学模型，包括水泥浆水平，混凝土水平，和混杂纤维增强混凝土水平，定量预测HFRC在环境温度下的有效各向同性和弹性性能。为了均匀化的目的，通过修改后的Power模型确定不同水平下不同相的体积分数。在多级细观力学模型中，综合考虑了水泥熟料、砂、粗骨料和混杂纤维的水化产物。提出了一种均匀化步进框架，实现了从HFRC细观结构性能到宏观结构有效弹性性能的尺度提升。此外，还提出了几个子步均匀化来估计等效介质的有效弹性性能相对于水泥浆和混杂纤维增强混凝土。与现有研究的实验数据进行比较，实现了一级一级。在此基础上，讨论了骨料、砂、纤维种类和水化程度对HFRC性能的影响。最后，研究了钢纤维和w/care的配合比对HFRC设计的影响，以获得预期的弹性性能。
There is a demand for multi scale micromechanical models to disclose and analyze the effects of microstructure on macro mechanical properties of hybrid fiber reinforced concrete (HFRC). This study involved presenting a multi-level micromechanical model that involves cement paste level, concrete level, and hybrid fiber reinforced concrete level to quantitatively predict the effective isotropic and elastic properties of HFRC under ambient temperature. For the purposes of homogenization, the volume fractions of different phases at different levels are determined by means of a modified Power’s model. In the multi-level micromechanical model, hydration products of clinker, sand, coarse aggregate, and hybrid fiber are comprehensively considered. A homogenization stepping framework is presented to realize upscaling from microstructural properties to the effective elastic properties of a macrostructure for HFRC. Additionally, several substepping homogenizations are also presented to estimate the effective elastic properties of an equivalent medium with respect to the cement paste and hybrid fiber reinforced concrete. Comparisons with experimental data from extant studies are implemented level by level. Subsequently, the influences of aggregate, sand, fiber type, and hydration degree on the properties of HFRC are discussed based on a proposed multi-level micromechanical model. Finally, the mixture ratio of steel fiber andw/care investigated with respect to the HFRC design to obtain anticipated elastic properties.