聚乙烯醇纤维混凝土损伤演化声发射监测及其评价  

Acoustic emission monitoring and evaluation of damage evolution for polyvinyl alcohol fiber concrete

作　　者：李冬生[1] 曹海[1] 

机构地区：[1]大连理工大学土木工程学院,辽宁大连116024

出　　处：《振动与冲击》2012年第9期29-32,43,共5页Journal of Vibration and Shock

基　　金：国家自然科学基金资助项目(50808030);教育部博士点基金新教师项目(200801411102)

摘　　要：通过对掺入聚乙烯醇(PVA)纤维混凝土试件进行三点抗弯的声发射试验,研究其损伤失效机理。首先,通过三点弯曲试验,得到了PVA纤维腐蚀前后混凝土的抗弯强度。然后,基于加载全过程中声发射特征信号,根据声发射幅值、计数和能量相关图,并通过比较有无腐蚀PVA纤维混凝土声发射信号,揭示了PVA纤维腐蚀混凝土的抗弯强度下降原因及其损伤机理。最后,借鉴NDIS-2421定量评定标准分析声发射信号,对混凝土试件的损伤情况做出定性评价,分析PVA纤维在腐蚀前后混凝土中的作用;此外,通过计算声发射特征信号裕度指标,发现PVA纤维混凝土弯曲损伤明显分为三个阶段,未腐蚀PVA纤维混凝土试件的裕度值较均匀。In order to research polyvinyl alcohol（PVA） fiber concrete failure mechanism,the acoustic emission（AE） monitoring technique was proposed.Through three-point bending experiment,flexure strength of PVA fiber concrete and AE characteristic signal has been obtained.According to the correlation diagram of AE amplitude,count and energy,the degeneration reason of flexural strength and the damage mechanism of corroded PVA fiber concrete were explained.NDIS-2421 quantitative evaluation criterion was used to assess the damage of concrete specimen,and the function of PVA fiber in corroded and uncorroded concrete was analyzed.Furthermore,the clearance factor of AE signal was computed.It is found that the process of bending damage of PVA fiber concrete is divided into three stages obviously,and the clearance factor of uncorroded PVA fiber concrete is relatively uniform.

关 键 词：PVA纤维混凝土 腐蚀 声发射 损伤评价 健康监测 

分 类 号：TU528[建筑科学—建筑技术科学]