分级加载下不同骨料粒径的混凝土声发射波速分析  

Acoustic emission wave velocity analysis of concrete with different aggregate particle size under graded loading

作　　者：范旭红[1] 赵金彪 杨帆[1] 李青 FAN Xuhong;ZHAO Jinbiao;YANG Fan;LI Qing(College of Mechanics and Civil Engineering,Jiangsu University,Zhenjiang 212013,China;Henan Highway Engineering Bureau Group Second Highway Engineering Co.,Ltd.,Zhengzhou 450015,China)

机构地区：[1]江苏大学力学与土木工程学院,江苏镇江212013 [2]河南省公路工程局集团第二公路工程有限公司,河南郑州450015

出　　处：《混凝土》2024年第3期6-11,16,共7页Concrete

基　　金：国家自然科学基金青年项目(52108148)。

摘　　要：目前利用声发射技术对混凝土结构进行损伤定位时,采用固定表面波速进行损伤定位,没有考虑混凝土声发射信号是从混凝土内部传播出来以及混凝土材料在不同的阶段产生的损伤对声发射波速的影响,导致检测结果与实际产生一定的偏差。以3种不同类型的弹性波速变化将混凝土的损伤化为5个阶段。利用波速的变化结合经典材料损伤力学从而进行材料损伤的定量分析。通过试验结果分析得出:当水灰比一定时,随混凝土粗骨料粒径的增大弹性波波速呈上升的趋势,但波速上升的趋势随粒径的增大而相对减小。随着应力的增加,波速降低时,波速与应力阶段存在一定的线性关系。采用不同加载阶段波速的不同进行变波速定位,定位精度更接近实际损伤位置,可有效提高定位精度。试验得出的结果为混凝土桥梁结构无损检测提供了新的思路方向为其安全检测提供了参考价值。At present,when the acoustic emission technology is used to locate the damage of concrete structure,the fixed surface wave velocity is used to locate the damage.The influence of the acoustic emission signal of concrete transmitted from the inside of the concrete and the damage of concrete materials at different stages on the acoustic emission wave velocity is not considered,resulting in a certain deviation between the test results and the actual situation.In this experiment,the damage of concrete is divided into five stages with three different types of elastic wave velocity changes.The quantitative analysis of material damage is carried out by using the change of wave velocity combined with the damage mechanics of classical materials.The experimental results show that when the water cement ratio is constant,the elastic wave velocity increases with the increase of concrete coarse aggregate particle size,but the upward trend of wave velocity decreases with the increase of particle size.With the increase of stress,the wave velocity decreases,and there is a certain linear relationship between the wave velocity and the stress stage.The positioning accuracy is closer to the actual damage location by using different wave velocities at different loading stages,which can effectively improve the positioning accuracy.The test results provide a new direction for nondestructive testing of concrete bridge structure and a reference value for its safety testing.

关 键 词：混凝土 分级加载 声发射 骨料粒径 波速 

分 类 号：TU528.01[建筑科学—建筑技术科学]