基于声发射的高强混凝土轴拉与劈拉损伤演化特征  

Damage Evolution Characteristics of High Strength Concrete under Axial Tension and Split Tension Based on Acoustic Emission

作　　者：陈育志[1,2] 宣卫红[1] 陈晨 唐建辉 徐文磊 CHEN Yuzhi;XUAN Weihong;CHEN Chen;TANG Jianhui;XU Wenlei(School of Architectural Engineering,Jinling Institute of Technology,Nanjing 211169,China;College of Civil and Transportation Engineering,Hohai University,Nanjing 210098,China;College of Water Conservancy&Hydropower Engineering,Hohai University,Nanjing 210098,China)

机构地区：[1]金陵科技学院建筑工程学院,江苏南京211169 [2]河海大学土木与交通学院,江苏南京210098 [3]河海大学水利水电学院,江苏南京210098

出　　处：《材料科学与工程学报》2024年第3期412-418,441,共8页Journal of Materials Science and Engineering

基　　金：江苏省产学研合作资助项目(BY2021059);金陵科技学院高层次人才资助项目(jit-b-202210)。

摘　　要：本研究对抗压强度约100 MPa的高强混凝土开展了轴拉和劈拉应力-应变全曲线试验,比较分析了两种试验全过程声发射特征,揭示了高强混凝土轴拉和劈拉破坏机制及损伤模式演化规律。研究表明:轴拉试样在峰值应力后受宏观裂缝不稳定扩展影响易发生偏心受拉,劈拉试样在峰值应力后应变分布较均匀,裂缝扩展较稳定;轴拉试样累计声发射撞击曲线在峰值应力处呈下凸型,而劈拉试样受局部集中应力影响累计声发射撞击曲线呈上凸型;轴拉试样受拉伸应力主导发生破坏,劈拉试样的破坏经历了拉剪混合破坏到拉伸破坏的转变。The whole stress-strain curve tests of axial tension and split tension were carried out on high strength concrete with a compressive strength of about 100 MPa.The acoustic emission characteristics of the two tests during the whole process were compared and analyzed,and the failure mechanism and damage evolution of high strength concrete were revealed.The results show that the axial tensile specimen is prone to eccentric tension due to the unstable expansion of macro-cracks after the peak stress,while the split tensile specimen has a more uniform strain distribution and stable crack propagation.The cumulative acoustic emission hits curve of the axial tension specimen is convex downward at the peak stress,while the curve of the split tension specimen affected by the local concentrated stress is convex upward.The failure of axial tensile specimen is dominated by tensile stress,and the failure of split tension specimen undergoes the transformation from tensile-shear mixed mode to tensile mode.

关 键 词：高强混凝土 轴拉 劈拉 应力-应变全曲线 声发射 损伤 

分 类 号：TU528.3[建筑科学—建筑技术科学]