新拌水泥基材料的流变特性、模型和测试研究进展

发布时间：2018-02-13 11:58

本文关键词： 新拌水泥基材料流变特性流变机理流变模型测试方法　出处：《硅酸盐学报》2017年05期 　论文类型：期刊论文

【摘要】：新拌的水泥基材料是典型的屈服应力流体,由不同粒径的固体颗粒形成的悬浮液组成,其固体颗粒的范围从亚微米级到厘米级。当受到剪切作用时流体内部存在两种相反的作用,分别会导致流体发生剪切稀化和剪切增稠,流体的流变特性由二者共同决定。本文对新拌水泥基材料的流变机理、模型以及流变仪测量方面的研究进展进行了综述,对具有代表性的流变模型,包括Bingham模型、Modified Bingham模型和Herschel-Bulkley模型等的特点、适用条件等进行了分类总结。影响流变特性的主要因素是固体颗粒体积分数和剪切速率,当剪切速率与剪切应力之间存在非线性关系时,难以根据流变仪的测量数据建立流变方程。本文中讨论了一些建立模型的新方法,通过计算流体力学和离散元理论相结合可以较好地模拟水泥基材料流变特性。
[Abstract]:The freshly mixed cement-based material is a typical yield stress fluid consisting of suspensions formed by solid particles of different sizes. The range of solid particles ranges from submicron to centimeter. There are two opposite effects in the fluid when it is subjected to shear action, which leads to shear thinning and shear thickening, respectively. The rheological properties of fluid are determined by both of them. This paper summarizes the research progress in rheological mechanism, model and rheometer measurement of fresh cement based materials, and gives a representative rheological model. The characteristics and applicable conditions of modified Bingham model and Herschel-Bulkley model of Bingham model are summarized. The main factors affecting rheological properties are volume fraction of solid particles and shear rate. When there is a nonlinear relationship between shear rate and shear stress, it is difficult to establish rheological equation based on the measured data of rheometer. In this paper, some new modeling methods are discussed. The rheological properties of cement-based materials can be well simulated by combining computational fluid dynamics with discrete element theory.
【作者单位】：中国建筑材料科学研究总院绿色建筑材料国家重点实验室;河南理工大学材料科学与工程学院;湖南大学土木工程学院;
【基金】：国家国际科技合作专项(2015DFA50880) 国家自然基金No.U1305243项目资助
【分类号】：TU528

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