混凝土劈裂抗拉强度和弯曲抗压强度尺寸效应的细观数值分析

发布时间：2018-01-19 19:35

本文关键词： 混凝土尺寸效应细观劈裂强度弯曲抗压强度数值模拟　出处：《工程力学》2014年10期 　论文类型：期刊论文

【摘要】：混凝土作为非均质材料,其材料性能存在随试件几何尺寸变化的尺寸效应。该文在细观层次上将混凝土看作由粗骨料、砂浆和二者界面过渡区组成的三相复合材料,采用刚体弹簧元数值方法模拟了混凝土的劈裂抗拉强度和弯曲抗压强度的尺寸效应,并与已有的试验结果进行了对比验证。结果表明:劈裂加载的试件破坏形态和劈裂抗拉强度与试验结果均具有良好的一致性,并且小尺寸试件所表现出的尺寸效应要明显于大尺寸试件;对不同尺寸四点弯曲钢筋混凝土梁开展细观数值分析得到跨中截面混凝土的弯曲抗压强度,随着梁有效高度的增加,名义弯曲抗压强度整体上呈现降低的趋势,但当梁有效高度大于240mm时趋于稳定。
[Abstract]:As a heterogeneous material, the material performance of concrete has the size effect of changing with the geometric size of the specimen. In this paper, the concrete is regarded as coarse aggregate on the meso level. The size effect of split tensile strength and flexural compressive strength of concrete is simulated by means of rigid body spring element method. The results show that the fracture morphology and tensile strength of the specimens subjected to splitting loading are in good agreement with the test results. The size effect of small size specimen is more obvious than that of large size specimen. The flexural compressive strength of concrete with mid-span section is obtained by the meso-numerical analysis of four-point bending reinforced concrete beams with different sizes. With the increase of the effective height of beams, the nominal flexural compressive strength decreases as a whole. However, when the effective height of the beam is more than 240 mm, the beam tends to be stable.
【作者单位】：大连理工大学海岸和近海工程国家重点实验室;中国航天建筑设计研究院(集团)济南分院;
【基金】：国家自然科学基金面上项目(51378090);国家自然科学基金重点项目(50838001)
【分类号】：TU528.01
【正文快照】： 混凝土是由粗细骨料、水泥水化物、孔隙以及骨料与水泥砂浆之间的界面粘结带等组成的非均质复合材料。在细观层次上,由于混凝土本身结构特性和各种缺陷的随机分布和随机增长,造成其材料性能存在随试件几何尺寸变化的尺寸效应[1]。目前对混凝土强度尺寸效应的研究主要有三个方

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