对不同级配(二级配、三级配、四级配)的混凝土在不同应变速率下(10-5/s,10-4/s,10-3/s,10-2/s)下进行了劈拉试验。对混凝土劈拉强度及轴向应变进行了深入分析,并利用实时采集的声发射数据分析了大体积混凝土在劈拉破坏全过程中的能量释放特性及破坏规律。结果表明:随应变速率的增加混凝土劈拉强度呈增加的趋势,混凝土级配越高劈拉强度变化的奇异性越大;混凝土劈裂抗拉破坏过程不具有典型未裂阶段、裂缝阶段和破坏阶段的3阶段特征,加载前期产生的声发射信号较微弱,材料达到峰值应力时能量信号突然急剧上升;采集的声发射数据能较真实地反映混凝土劈拉破坏全过程。
邹三兵
,
胡伟华
,
黄仕超
,
彭刚
. 基于声发射参数的不同级配混凝土动态劈拉试验研究[J]. 长江科学院院报, 2015
, 32(10)
: 111
-115
.
DOI: 10.11988/ckyyb.20140392
Splitting tensile tests were conducted on concrete with different gradations (two gradations, three gradations, and four gradations) under different strain rates (10-5/s, 10-4/s, 10-3/s, 10-2/s). The splitting tensile strength and axial strain of concrete were analyzed, and the energy release characteristics and damage regularity of mass concrete in the whole process of splitting tensile damage were researched through collected real-time acoustic emission data. Results show that with the strain rate increasing, the splitting tensile strength of concrete displays a trend of increasing. Singularity in the variation of splitting tensile strength is larger when the gradation of concrete is higher. The process of splitting tensile failure does not have the characteristics of a typical three-stage: stage without cracks, stage with cracks, and stage of failure. The acoustic emission signal is weak in the early stage of loading, but rises sharply when the material reaches peak stress. Acoustic emission data can truly reflect the process of concrete splitting tensile failure.
[1] 宋玉普,吕培印,侯景鹏.有侧压混凝土的变速率劈拉强度试验及其破坏准则研究[J]. 水利学报,2002,(3):1-5.(SONG Yu-pu,LU Pei-yin,HOU Jin-pen. Concrete Splitting Tensile Strength and Failure Criterion for Different Loading Rate and Lateral Stress[J]. Journal of Hydraulic Engineering,2002,(3):1-5.(in Chinese))
[2] 尚仁杰,赵国藩,黄承逵.低周循环荷载作用下混凝土轴向拉伸全曲线的试验研究[J].水利学报,1996,(7):82-87.(SHANG Ren-jie,ZHAO Guo-fan,HUANG Cheng-kui.Experimental Investigation of Complete Stress-deformation Curves for Concrete under Low Frequency Cyclic Load[J]. Journal of Hydraulic Engineering,1996,(7):82-87.(in Chinese) )
[3] 肖诗云,林 皋,王 哲,等.应变率对混凝土抗拉特性影响[J].大连理工大学学报,2001,(6):721-725.(XIAO Shi-Yun,LIN Gao,WANG Zhe,et al.Effects of Strain Rate on Dynamic Behavior of Concrete in Tension[J]. Journal of Dalian University of Technology,2001,(6):721-725.(in Chinese))
[4] 孙吉书,窦远明,于 龙.混凝土单轴动态抗拉特性的试验研究[J].河北工业大学学报,2012,(1):81-84.(SUN Ji-shu,DOU Yuan-ming,YU Long.Experimental Study on The Uniaxial Dynamic Tensile Properties of Concrete[J]. Journal of Hebei University of Technology,2012,(1):81-84.(in Chinese))
[5] 范立新,焦楚杰,张亚芳,等.混凝土动态拉伸试验与数值研究进展[J].混凝土,2013,(2):12-16,20.(FAN Li-xin,JIAO Chu-jie,ZHANG Ya-fang,et al.Concrete Dynamic Tensile Experiments and Progress of Numerical Study[J].Concrete,2013,(2):12-16,20.(in Chinese))
[6] 卢玉斌,武海军,赵隆茂.混凝土类材料动态拉伸强度的微观力学模型[J].爆炸与冲击,2013,(3):275-281.(Lu Yu-bin,Wu Hai-jun,ZHAO Long-mao.A Micro-mechanical Model for Dynamic Tensile Strength[J].Explosion and Shock Waves, 2013,(3):275-281. (in Chinese))
[7] 陈荣刚,张 凯.混凝土动态直接拉伸实验相关问题研究[J].舰船电子工程,2013,(6):156-158,165.(CHEN Rong-gang,ZHANG Kai.Investigation of Experimental Issues on the Test of Dynamic Direct Tension for Concrete[J].Ship Electronic Engineering, 2013,(6):156-158,165. (in Chinese))
