马宝玉, 兑关锁, 阳生有. 基于多项材料细观力学的混凝土干缩量预估[J]. 工程力学, 2014, 31(12): 104-111. DOI: 10.6052/j.issn.1000-4750.2013.07.0610
引用本文: 马宝玉, 兑关锁, 阳生有. 基于多项材料细观力学的混凝土干缩量预估[J]. 工程力学, 2014, 31(12): 104-111. DOI: 10.6052/j.issn.1000-4750.2013.07.0610
MA Bao-yu, DUI Guan-suo, YANG Sheng-you. PREDICTION OF THE DRYING SHRINKAGE OF CONCRETE BASED ON MICRO-MECHANICS[J]. Engineering Mechanics, 2014, 31(12): 104-111. DOI: 10.6052/j.issn.1000-4750.2013.07.0610
Citation: MA Bao-yu, DUI Guan-suo, YANG Sheng-you. PREDICTION OF THE DRYING SHRINKAGE OF CONCRETE BASED ON MICRO-MECHANICS[J]. Engineering Mechanics, 2014, 31(12): 104-111. DOI: 10.6052/j.issn.1000-4750.2013.07.0610

基于多项材料细观力学的混凝土干缩量预估

PREDICTION OF THE DRYING SHRINKAGE OF CONCRETE BASED ON MICRO-MECHANICS

  • 摘要: 混凝土的干缩特性一直是学术与工程界关注的问题之一。该文用细观力学方法对混凝土相对于水泥浆体的干缩率进行研究。假定混凝土为由骨料和水泥浆体组成的二相材料,根据混凝土收缩量与组成混凝土的各相介质收缩量之和相等的原则,分别用基于Eshebly等效夹杂理论的Mori-Tanaka方法和基于载荷叠加思想的细观力学方法推导了混凝土干缩量。结果表明:Mori-Tanaka法、自洽方法和经验公式得到的相对干缩量基本相同,能很好地反映混凝土的干缩特性。混凝土相对干缩随骨料体积分数的增加而下降,随水泥基质泊松比的增大而增加。相对干缩随骨料与水泥基质体积模量比的增大而减小,但是当其值大于5后的影响比较小。用该文的方法估算混凝土的干缩,物理意义明确且计算简单,可以减少实验的工作量,同时也为混凝土结构的设计提供一定的参考。

     

    Abstract: The drying shrinkage of concrete has been concerned by engineers and researchers for a long time. This paper analyzes the ratio of concrete/cement drying shrinkage by using micro-mechanics. Assuming concrete as a two phase composite material composed of cement and aggregate and according to the change of the volume of concrete to the same as that of the sum of all the constituents, the drying shrinkage of concrete is respectively obtained by using the Mori-Tanaka method based on Eshebly equivalent inclusion theory and the method of micro-mechanics based on load superposition. The study shows that the numerical results obtained from the methods of Mori-Tanaka and self-consistent are consistent with that of the empirical formula. Hence the methods can be used to analyze the drying shrinkage of concrete. The ratio of concrete/cement drying shrinkage decreases with the increase of the volume fraction of aggregates, but increases with the increase of the Poisson's ratio of the cement. The increase of the ratio of aggregate/cement matrix bulk modulus will decrease the drying shrinkage, but it has little effect when the ratio exceeds 5. The methods used in this paper have clear physical meaning and easy calculation. It also can reduce the experimental works and provide useful suggestions for the design of concrete structures.

     

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