钢绞线的黏结性能试验研究  

Experimental study on bond performance of steel strands

作　　者：刘贝[1] 张继文[1,2] 李星 郝天择 LIU Bei;ZHANG Jiwen;LI Xing;HAO Tianze(School of Civil Engineering,Southeast University,Nanjing 210096,Jiangsu,China;Key Laboratory of C&PC Structures of Ministry of Education,Southeast University,Nanjing 210096,Jiangsu,China)

机构地区：[1]东南大学土木工程学院,江苏南京210096 [2]东南大学混凝土及预应力混凝土教育部重点实验室,江苏南京210096

出　　处：《建筑科学与工程学报》2023年第6期91-100,共10页Journal of Architecture and Civil Engineering

基　　金：国家重点研发计划项目(2017YFC0703000)。

摘　　要：为研究钢绞线在混凝土中的黏结性能,设计制作了16组钢绞线-混凝土拉拔试件,进行了钢绞线的单调拉拔试验,分别从破坏模式、峰值荷载、峰值滑移等方面对比分析了锚固方式(直线型锚固及90°弯折锚固)和锚固长度(总锚固长度及竖直锚固段长度)对钢绞线黏结性能的影响规律。结果表明:16组试件的破坏分为2类破坏模式(钢绞线的拔出破坏、钢绞线的断裂破坏),在设计中应该将钢绞线的断裂破坏作为极限状态;钢绞线的直线型锚固方式难以保证钢绞线强度的充分利用,与直线型锚固试件相比,90°弯折锚固试件的峰值荷载更大,峰值滑移更小;总锚固长度le≥500 mm是保证钢绞线强度充分利用的前提,在此条件下,总锚固长度le取600 mm对于限制90°弯折钢绞线的峰值滑移最有效;在保证一定水平锚固段长度的前提下,钢绞线的竖直锚固段长度lv越大,试件的峰值滑移越小;当钢绞线竖直锚固段长度lv取10d(d为钢绞线公称直径)时,峰值滑移的下降最明显,非线性滑移阶段锚固刚度的退化最小;实际工程中,当钢绞线采用90°弯折锚固方式时,总锚固长度宜取600 mm,竖直锚固段长度宜取10d。In order to study the bond performance of steel strands,16 groups of steel strand-concrete pull-out specimens were designed and manufactured.A monotonic pull-out test was conducted on steel strands,and the influence of anchoring form(linear anchoring and 90°bending anchoring)and anchoring lengths(total anchoring length and vertical anchoring section length)on the bonding performance of steel strands was compared and analyzed from the aspects of failure mode,peak load,and peak slip.The results show that the failure of 16 groups of specimens is divided into two types of failure modes(pull-out failure of steel strands and fracture failure of steel strands),and the fracture failure of steel strands should be considered as the limit state in the design.The linear anchoring method of steel strands is difficult to ensure the full utilization of steel strand strength.Compared with the linear anchoring specimen,the 90°bending anchoring specimen has a larger peak load and smaller peak slip.The total anchoring length l e≥500 mm is a prerequisite to ensure the full utilization of the strength of the steel strand.Under this condition,taking a total anchoring length l e of 600 mm is the most effective way to limit the peak slip of the 90°bending steel strand.On the premise of ensuring a certain length of horizontal anchoring section,the larger the anchoring length l v of the vertical section of the steel strand,the smaller the peak slip of the specimen.When the length l v of the vertical anchoring section of the steel strand is taken as 10 d(d is the nominal diameter of the steel strand),the decrease in peak slip is the most significant,and the degradation of anchoring stiffness during the nonlinear slip stage is the smallest.In practical engineering,when the steel strand adopts 90°bending anchoring method,the total anchoring length should be taken as 600 mm,and the length of the vertical anchoring section should be taken as 10 d.

关 键 词：钢绞线 锚固方式 锚固长度 黏结性能 

分 类 号：TU378.8[建筑科学—结构工程]