(上海市建筑科学研究院有限公司 上海市工程结构安全重点实验室, 上海 200032)

摘要: 设计制作了 9 组共 78 个螺旋箍筋约束高强钢筋浆锚搭接试件,通过单向拉拔试验,研究了其破坏机理以及钢筋强度、混凝土强度、钢筋搭接长度、螺旋箍筋形式等因素对搭接性能的影响. 结果表明:未配置螺旋箍筋的浆锚搭接试件主要破坏模式为混凝土的锚固失效开裂,且其承载力和强屈比随钢筋搭接长度的增加逐渐增加;配置螺旋箍筋后,钢筋搭接长度大于 0. 80lab(lab 为钢筋基本锚固长度)时,试件主要破坏模式为钢筋受拉屈服且其极限承载力较稳定;钢筋搭接长度为 0. 56lab 时,试件端部混凝土出现开裂,部分试件的极限承载力显著降低. 建议实际工程中钢筋直径为 16mm 时,螺旋箍筋约束高强钢筋浆锚搭接的搭接长度取 0. 80lab ;其他直径钢筋可参考该搭接长度并经过试验验证后应用.

关键词: 高强钢筋; 浆锚搭接; 螺旋箍筋; 搭接长度; 单向拉伸

中图分类号:TU375 文献标志码:A 文章编号:1002-848X(2023)08-0119-06

DOI:10. 19701 / j. jzjg. LS202045

Uniaxial tension experimental study on the grouting-anchoring overlap-joint of high strength steel bar restrained by spiral stirrups

WANG Zhuolin, LI Xiangmin, TIAN Kun, WANG Mingqian

(Shanghai Key Laboratory of Engineering Structure Safety, Shanghai Research Institute of Building Sciences Co. ,Ltd. , Shanghai 200032, China)

Abstract: Nine groups of seventy-eight specimens of grouting-anchoring overlap-joint of high strength steel bar restrained byspiral stirrups were designed and fabricated. The failure mechanism and the influence of steel bar strength, concretestrength, lapping length of steel bars and spiral stirrup type on the lapping property were investigate by uniaxial tensiontests. The results show that the main failure mode of the specimens without spiral stirrups was the anchorage failure andcracking of concrete, and the bearing capacity and ductility ratio increase with the increase of lapping length of steel bars.The main failure mode of specimens restrained by spiral stirrups is steel bar tensile yield, when the lapping length is over0. 80lab(labis the basic anchorage length of the steel bar), and the bearing capacity of restrained specimens is very stable.When the lapping length of steel bars is 0. 56lab , concrete crackes at the end of the restrained specimens, and the bearingcapacity of some specimens decrease significantly. It is suggested that when the diameter of steel bar is 16mm in practicalengineering, the lapping length of high strength bars should not be less than 0. 80lab. The suggested lapping length can berefereed for high strength bars with other diameters, and be verified by the test before application.

Keywords:high strength steel bar; grouting-anchoring overlap-joint; spiral stirrup; lapping length; uniaxial tension

∗国家重点研发计划项目(2022YFF0609200),上海市科学技术委员会项目(18DZ1205705).

第一作者:王卓琳,博士,教授级高级工程师,主要从事建筑检测评估与加固改造领域的研究与实践,Email: wzllzw@ 163. com.

[引用本文] 王卓琳,李向民,田坤,等. 螺旋箍筋约束高强钢筋浆锚搭接单向拉伸试验研究[J]. 建筑结构,2023,53(8):119-124. WANG Zhuolin,LI Xiangmin,TIAN Kun,et al. Uniaxial tension experimental study on the grouting-anchoringoverlap-joint of high strength steel bar restrained by spiral stirrups[J]. Building Structure,2023,53(8):119-124.