混凝土冻融劣化后动态单轴抗压特性试验研究

发布时间：2019-04-21 16:53

【摘要】：为研究混凝土冻融循环后的动态力学性能,利用10 MN动静三轴仪对不同冻融劣化程度的混凝土在不同加载速率下进行单轴压缩试验,同时采集声发射数据分析试验过程中能量释放及损伤演化规律。最后,选用Weibull-Lognormal损伤本构模型,对试验数据进行拟合分析,并分析不同工况混凝土的损伤随应变的发展规律。研究结果表明:(1)相同冻融劣化程度时,随应变速率增加,峰值应力增大,峰值应变减小;冻融劣化程度会影响峰值应力的率敏感性;(2)在应变速率相同时,随冻融循环次数增加,峰值应力随之减小,峰值应变随之增大。(3)混凝土冻融劣化后应力应变关系峰前服从Weibull统计分布,峰后服从Lognormal统计分布。(4)在相同应变速率下,随着冻融循环次数的增加,混凝土的累计塑性应变整体呈增大趋势。
[Abstract]:In order to study the dynamic mechanical properties of concrete after freezing-thawing cycle, uniaxial compression tests of concrete with different freeze-thaw degradation degrees were carried out with 10 MN dynamic-static triaxial apparatus under different loading rates. At the same time, acoustic emission data were collected to analyze the law of energy release and damage evolution during the experiment. Finally, the Weibull-Lognormal damage constitutive model is selected to fit the test data and analyze the development rule of concrete damage with strain under different working conditions. The results show that: (1) the peak stress increases and the peak strain decreases with the increase of strain rate at the same degree of freeze-thaw deterioration, and the sensitivity of the peak stress is influenced by the degree of freeze-thaw degradation. (2) when the strain rate is the same, the peak stress decreases and the peak strain increases with the increase of freezing and thawing cycles. (3) the stress-strain relationship obeys Weibull statistical distribution before the peak of freeze-thaw deterioration. The peak post-peak obeys Lognormal statistical distribution. (4) at the same strain rate, the cumulative plastic strain of concrete increases with the increase of freeze-thaw cycle times.
【作者单位】：三峡大学土木与建筑学院;三峡地区地质灾害与生态环境湖北省协同创新中心;
【基金】：国家自然科学基金资助项目(51279092,51579139) 三峡大学研究生科研创新基金资助项目(SDYC2016024)
【分类号】：TU528

【相似文献】