混凝土板裂缝的超声红外热像检测机理  

Mechanism of Ultrasonic Infrared ThermographyDetection of Concrete Slab Cracks

作　　者：蒋雅君[1] 任荣[1] 冯辅周 赵菊梅[1] JIANG Yajun;REN Rong;FENG Fuzhou;ZHAO Jumei(Key Laboratory of Transportation Tunnel Engineering,Ministry of Education,Southwest Jiaotong University,Chengdu 610031,China;Department of Vehicle Engineering,Academy of Army Armored Forces,Beijing 100072,China)

机构地区：[1]西南交通大学交通隧道工程教育部重点实验室,成都610031 [2]陆军装甲兵学院车辆工程系,北京100072

出　　处：《北京工业大学学报》2022年第10期1028-1035,共8页Journal of Beijing University of Technology

基　　金：国家自然科学基金资助项目(51875576)。

摘　　要：为探讨超声红外热像对混凝土裂缝检测的机理,设计带有预制裂缝的混凝土板试件,采用超声红外热像检测系统开展超声激励下混凝土板裂缝生热试验.通过分析裂缝生热的红外热像图和试验后裂缝表面的显微成像,归纳超声激励下混凝土板裂缝的生热机理;基于裂缝的生热机理,分析预紧力、激励时间和激励强度对裂缝生热的影响.试验结果表明:裂缝生热来源于裂缝面的接触、碰撞和滑移作用,裂缝面中下部为主要生热区域且裂缝面平整无填充物.增大预紧力、激励时间和激励强度都能使得更多的超声能注入至混凝土板试件,从而促进裂缝生热量的增多;当预紧力为110~120 N且激励强度为21%~24%时,裂缝具有良好的热响应,利于检测识别.To identify the mechanism of ultrasonic infrared thermal image detection of concrete crack detection,the concrete slab specimens with prefabricated cracks were designed,and the thermal test of concrete slab cracks under ultrasonic excitation was carried out by using the ultrasonic infrared thermal image detection system.By analyzing the infrared thermal image of the crack heating and the microscopic image of the crack surface after the test,the heating mechanism of the concrete slab crack under ultrasonic excitation was summarized.Based on the heat generation mechanism of cracks,the effects of pre-tightening force,excitation time and excitation intensity on the crack heating were analyzed.The test results indicate that the crack heating originates from the contact,collision and slippage of the crack surface.The middle and lower parts of the crack surface are the main heat generation areas,and the crack surface is flat and without filler.Increasing pre-tightening force,excitation time and excitation intensity can input more ultrasonic energy into concrete slab specimens,thus promoting the increase of crack heating.When the pre-tightening force is 110-120 N and the excitation intensity is 21%-24%,the cracks have good thermal response,which is conducive to detection and identification.

关 键 词：超声红外热像 混凝土板裂缝 激励参数 接触与生热效应 试验研究 数值模拟 

分 类 号：TU375.2[建筑科学—结构工程]