不同加载速率下蒸养混凝土单轴压缩声发射特性研究  

Study on acoustic emission characteristics of steam-cured concrete under uniaxial compression at different loading rates

作　　者：袁志颖 陈波[1,2] 陈家林 高志涵 YUAN Zhiying;CHEN Bo;CHEN Jialin;GAO Zhihan(College of Water-conservancy and Hydropower,Hohai University,Nanjing 210098,China;State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering,Hohai University,Nanjing 210098,China)

机构地区：[1]河海大学水利水电学院,江苏南京210098 [2]河海大学水文水资源与水利工程科学国家重点实验室,江苏南京210098

出　　处：《混凝土》2024年第3期30-34,41,共6页Concrete

基　　金：国家自然科学基金面上项目(52079049);国家自然科学基金重点项目(51739003)。

摘　　要：为研究加载速率对蒸养混凝土受压破坏过程中声发射特性的影响,针对蒸养混凝土试件开展3种加载速率工况单轴压缩试验,并利用声发射技术对试验全过程进行动态监测,分析了不同加载速率下蒸养混凝土内部声发射特征参数的变化特征。结果表明:不同加载速率下蒸养混凝土受压破坏过程的声发射振铃计数变化呈现接触期、平静期、陡增期的三阶段变化规律,随加载速率增加,振铃计数率和能量计数率峰值逐渐增大,累计振铃计数和累计能量计数逐渐减小。低加载速率下,声发射幅度分布较为稀疏,内部损伤信号多而分散;高加载速率下,声发射幅度分布较为密集,内部损伤信号少而集中。声发射Ib值随加载进程呈现上升、波动和下降的演化过程,随加载速率的增加,混凝土试件破裂模式由剪切破坏向拉伸破坏的趋势演变。In order to study the influence of loading rate on the acoustic emission characteristics of steam-cured concrete in the process of compression failure,the uniaxial compression tests of steam-cured concrete specimens under three loading rates were carried out,the whole process of the test was dynamically monitored by acoustic emission technology,and the variation characteristics of acoustic emission characteristic parameters of steam-cured concrete under different loading rates were analyzed.The results show that under different loading rates,the change of acoustic emission ring count in the compression failure process of steam cured concrete presents the three-stage change law of contact period,calm period and steep increase period.With the increase of loading rate,the peak value of ring count rate and energy count rate gradually increases,and the cumulative ring count and cumulative energy count gradually decrease.At low loading rate,the distribution of acoustic emission amplitude is sparse,and the internal damage signals are more and scattered,at high loading rate,the distribution of acoustic emission amplitude is dense,and the internal damage signals are few and concentrated.The acoustic emission Ib value shows an evolutionary process of rising,fluctuating and falling with the loading process.With the increase of loading rate,the fracture mode of concrete specimens changes from shear failure to tensile failure.

关 键 词：不同加载速率 蒸养混凝土 单轴压缩 声发射 

分 类 号：TU528.064[建筑科学—建筑技术科学]