混凝土硬化变形特征与破坏规律相关性实验研究

发布时间：2018-03-31 05:04

  本文选题：混凝土硬化变形　切入点：数字散斑相关方法　出处：《混凝土》2017年08期

【摘要】：通过CCD相机搭建试验的数据采集系统,以数字散斑相关方法对试验中采集的散斑图像数据进行分析,研究混凝土试件硬化过程中试件表面变形场演化特征及其对后期受载破坏规律的影响。试验结果表明:(1)混凝土硬化变形时空演化表现为变形缓慢增加、变形快速增加、变形稳定3个阶段特征;混凝土硬化变形时空演化过程是一个从拉、压区域不断调整到最终稳定的动态过程,调整过程中在受拉区形成损伤集中区;混凝土硬化变形场空间演化特征表现为由不均匀分布演化为拉、压应变区域呈条状相间的分布状态。(2)受载过程中裂纹在硬化变形受拉较大的区域开始发育,随着荷载的增加裂纹沿着硬化过程中形成的条状受拉区域扩展成宏观裂纹且试件表面裂纹具有等距分布特征。
[Abstract]:The experimental data acquisition system is built by CCD camera, and the speckle image data collected in the experiment are analyzed by digital speckle correlation method. The evolution characteristics of the surface deformation field of concrete specimens during the hardening process and its influence on the law of post-loading failure are studied. The experimental results show that the space-time evolution of concrete hardening deformation shows a slow increase in deformation and a rapid increase in deformation. The space-time evolution process of concrete hardening deformation is a dynamic process from tension and compression region to final stability, and the damage concentration zone is formed in the tensile zone during the adjustment process. The spatial evolution of the hardening deformation field of concrete is characterized by the evolution from uneven distribution to tension, and the crack begins to develop in the area where the hardening deformation is larger during the loading process, and the compressive strain region is in the form of a strip-like distribution state. With the increase of load, the crack propagates into macroscopic crack along the strip tensile region formed during the hardening process, and the crack on the surface of the specimen has the isometric distribution characteristic.
【作者单位】： 北方工业大学土木工程学院;
【基金】：国家自然科学基金(51474013)
【分类号】：TU528
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本文编号：1689249