摘要
制作两个含Ⅰ型预制裂缝的混凝土试件并进行三点弯曲试验,在其中一个试件底面粘贴碳纤维板进行加固,以CCD相机为观测系统,用数字散斑技术对混凝土试件预制裂缝尖端的扩展特征、裂缝尖端张开位移及应力强度因子等进行分析,研究了碳纤维复合材料(CFRP)板的加固效果。结果表明:外贴CFRP板加固能增加混凝土的抗弯刚度,显著提高混凝土的抗弯承载力,延缓裂缝开展;在相同荷载作用下,外贴CFRP板加固可以减小试件预制裂缝扩展宽度和距离;外CFRP板加固含Ⅰ型预制裂缝混凝土试件的裂缝尖端应力强度因子增加速度小于相同的未粘贴CFRP板混凝土试件。
Two concrete specimens with pre-crack of type I were fabricated and three-point bending test was carried out.Carbon fiber sheets were affixed to the bottom of one of the specimens for reinforcement.The deformation measurement system was built with two CCD cameras.By using digital speckle technique,the extended characteristics,crack tip opening displacement and stress intensity factor of the pre-crack tip for concrete specimens were analyzed to study the CFRP reinforcement effect.The results show that the external CFRP reinforcement can increase the flexu-ral rigidity of concrete,significantly improve the bending capacity of concrete and delay the crack development.Under the same load,the CFRP plate reinforcement can reduce the propagation distance and width of the pre-crack tip of the test piece.The increase of the stress intensity factor of the crack tip of the concrete specimen reinforced with the externally CFRP sheet is less than that of the same unreinforced concrete specimen.
作者
韩艳
王龙龙
刘志浩
HAN Yan;WANG Longlong;LIU Zhihao(School of Civil Engineering,North China University of Technology,Beijing 100144)
出处
《材料导报》
EI
CAS
CSCD
北大核心
2019年第S02期304-308,共5页
Materials Reports
基金
北京市属高校基本科研业务费项目(110052971921/058)~~
