摘要
为研究锚固区钢绞线锈断对后张预应力混凝土梁黏结性能的影响,对6根预应力混凝土构件进行静力拉拔试验。通过设计电化学快速锈断钢绞线、缓慢切割钢绞线和直接放张3种应力释放方式,研究应力释放方式、混凝土强度和箍筋直径对断后预应力钢绞线黏结性能的影响,揭示预应力钢绞线与混凝土黏结力沿纵向的分布规律,得到预应力钢绞线的黏结-滑移曲线以及试件达最大拉拔力时预应力混凝土梁的裂缝分布形态。试验结果表明:钢绞线与混凝土的黏结破坏由拉拔端逐渐向自由端发展,应力释放速度越缓,试件初始损伤越小,拉拔过程中黏结性能越稳定;提高混凝土强度等级和增大箍筋直径均可提高预应力钢绞线与混凝土间的黏结强度;试件破坏形式主要为黏结失效或预应力钢绞线断裂破坏。本研究为完善锈蚀钢绞线与混凝土间黏结性模型提供了试验基础。
To study the influence of the strand corrosion in anchorage zone on the bond performance of post-tensioned prestressed concrete beams,static pull-out tests were conducted on six prestressed concrete members.Three types of stress release methods were designed:Accelerated corrosion-induced fracture of steel strands,cutting steel strands and direct release strands.The effects of stress release forms,concrete strength,and stirrup diameter on the bond behavior of fractured tendons were analyzed.The distribution of the bond between prestressed strands and concrete in longitudinal direction was revealed.The bond-slip curves and the crack distribution of the prestressed concrete beam when the specimen reaches the ultimate pullout force were also discussed.The results show that the bond failure between steel strands and concrete gradually develops from the loading end to the free end.The bond performance of member with a slow stress release rate is smaller the initial damage of the specimen and more stable in the loading process.Increasing the concrete strength level and stirrup diameter can increase the bond between prestressed strands and concrete.The main failure mode of the specimen is bond failure orprestressed strands fracture.This study provides an experimental basis for improving the bond model between corroded prestressing strands and concrete.
作者
马亚飞
李晶
苏小超
王磊
张建仁
MA Yafei;LI Jing;SU Xiaochao;WANG Lei;ZHANG Jianren(School of Civil Engineering,Changsha University of Science&Technology,Changsha 410114,China)
出处
《铁道科学与工程学报》
CAS
CSCD
北大核心
2021年第4期966-975,共10页
Journal of Railway Science and Engineering
基金
国家自然科学基金资助项目(51778068,51678069)
湖南省自然科学基金资助项目(2019JJ30024)
长沙市杰出创新青年培养计划项目(kq1802012)。
关键词
预应力束
拉拔试验
应力释放
黏结性能
prestressing strand
pull-out test
stress relief
bonding performance
