杜拉纤维混凝土力学性能及早期裂缝的分形研究

发布时间：2018-02-23 01:19

本文关键词： 杜拉纤维骨料级配分形特征力学性能塑性开裂分形维数　出处：《内蒙古农业大学》2013年硕士论文　论文类型：学位论文

【摘要】：自水泥混凝土问世以来，裂缝问题一直困扰着人们，许多学者试图用不同的方法解决收缩裂缝。由于长期以来对砂石骨料的研究不大重视，使很多工程中出现的混凝土缺陷难于解释。因而,本文着重从混凝土的骨料和在混凝土中加入杜拉纤维两个方面来研究混凝土的性能及其早期裂缝。本文通过骨料级配分维值的不同和杜拉纤维掺量的不同，研究骨料分维值和杜拉纤维掺量对混凝土力学性能的影响；通过平板试验，研究杜拉纤维混凝土骨料级配的分形特征及纤维掺量对其早期表面塑性开裂的影响两个方面。结果表明: 1．骨料的分维值为2.4的混凝土试块抗压强度和抗折强度是最大的，骨料分维对于混凝土的抗压和抗折强度的影响不同，，所以对于不同分维值混凝土的抗压强度和抗折强度的走势不同。 2．杜拉纤维的掺入对混凝土抗折强度的影响明显优于其对抗压强度的影响，且1.0kg/m~3掺量的效果优于0.5kg/m~3掺量的效果。 3．随着骨料级配分维值的增大，混凝土早期塑性开裂的越严重，总开裂面积增大，但是其初裂时间却越来越长。 4．杜拉纤维对混凝土早期塑性裂缝的抑制有很好的作用。运用分形维数能够更直接、明了的对混凝土的早期开裂做出评价。
[Abstract]:Since the advent of cement concrete, the problem of cracks has been puzzling people. Many scholars try to solve shrinkage cracks with different methods. It is difficult to explain the concrete defects in many projects. Therefore, this paper focuses on the performance of concrete and its early cracks from the aspects of concrete aggregate and the addition of Dura fiber in concrete. In this paper, the effects of aggregate fractal dimension and Dura fiber content on the mechanical properties of concrete are studied by using the different fractal dimension of aggregate gradation and the different content of Dura fiber, and the effects of the fractal dimension of aggregate and the content of Dura fiber on the mechanical properties of concrete are studied. The fractal characteristics of aggregate gradation of Dura fiber concrete and the effect of fiber content on early surface plastic cracking are studied. The results show that:. 1. The compressive strength and flexural strength of concrete specimens with a fractal dimension of 2.4 are the largest, and the effects of fractal dimension of aggregate on the compressive and flexural strength of concrete are different. So the compressive strength and flexural strength of concrete with different fractal dimension are different. 2. The effect of the addition of Dura fiber on the flexural strength of concrete is obviously better than that on the compressive strength of concrete, and the effect of 1.0 kg / m ~ (-3) is better than that of 0.5 kg / m ~ (3). 3. With the increase of the fractal dimension of aggregate gradation, the more serious the early plastic cracking of concrete is, the larger the total crack area is, but the longer the initial crack time is. 4. Dura fiber has a good effect on the suppression of early plastic crack of concrete. The fractal dimension can be used to evaluate the early crack of concrete more directly and clearly.
【学位授予单位】：内蒙古农业大学
【学位级别】：硕士
【学位授予年份】：2013
【分类号】：TU528.572

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