不同密度等级泡沫混凝土的单轴压缩破坏特征  

Failure Characteristics of Foam Concrete with Different Density under Uniaxial Compression

作　　者：李升涛 陈徐东[1] 张锦华 董文 LI Shengtao;CHEN Xudong;ZHANG Jinhua;DONG Wen(College of Civil Engineering and Transportation,Hohai University,Nanjing 210098,China;School of Civil Engineering,Southeast University,Nanjing 210098,China;Unit 96901,Beijing 100089,China)

机构地区：[1]河海大学土木与交通学院,江苏南京210098 [2]东南大学土木工程学院,江苏南京210098 [3]96901部队,北京100089

出　　处：《建筑材料学报》2021年第6期1146-1153,共8页Journal of Building Materials

基　　金：国家自然科学基金资助项目(51979090);江苏省自然科学优秀青年基金资助项目(BK20190075);中央高校基本科研业务费专项资金(B200202076)。

摘　　要：为研究不同密度泡沫混凝土的压缩破坏特征,对密度为500~750 kg/m^(3)的泡沫混凝土开展了不同加载速率下的单轴压缩试验,并采用数字图像相关(DIC)技术和声发射(AE)技术,获得了泡沫混凝土加载过程中的应变云图以及损伤演化特征.结果表明:随着密度的增大,泡沫混凝土的屈服应力、平台应力和能量吸收明显提高,荷载速率的影响更加明显;泡沫混凝土破坏时的裂缝数量减少,裂缝由垂直微裂纹转为带有倾斜角度的剪切型裂纹;声发射信号在峰前的活跃度增加,泡沫混凝土发生破坏时振铃计数突增现象更加集中;泡沫混凝土由延性破坏转变为脆性破坏.To study the compression failure characteristics of foam concrete with different density,uniaxial compression tests of foamed concrete with density of 500-750 kg/m^(3) were carried out at different loading rates.Based on digital image correlation(DIC)and acoustic emission(AE)technology,the damage evolution of foam concrete was analyzed.The results show that with the increase of density,the yield stress,platform stress and energy absorption increase obviously.At the same time,the influence of loading rate is more obvious.The number of cracks decreases when the foam concrete is damaged,and the cracks change from vertical micro⁃cracks to shear cracks with inclined angle.The activity of AE signal before the peak increases,and the sudden increase of ring count is more concentrated at the damage.The failure behavior shows the tendency from ductile failure to brittle failure.

关 键 词：泡沫混凝土 数字图像相关 声发射 单轴压缩 

分 类 号：TU528.01[建筑科学—建筑技术科学]