| 引用本文: | 余琼,许志远,袁炜航,吕西林.两种因素影响下套筒约束浆锚搭接接头拉伸试验[J].哈尔滨工业大学学报,2016,48(12):34.DOI:10.11918/j.issn.0367-6234.2016.12.004 |
| YU Qiong,XU Zhiyuan,YUAN Weihang,Lü Xilin.Experimental study of grouted sleeve lapping connectors varied in two factors under tensile load[J].Journal of Harbin Institute of Technology,2016,48(12):34.DOI:10.11918/j.issn.0367-6234.2016.12.004 |
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| 摘要: |
| 为改善已有套筒灌浆接头的施工便利性，提出了一种有自主知识产权的套筒约束浆锚搭接接头，研究了该搭接接头的连接性能，为其在装配式构件中应用提供力学数据.进行了以钢筋直径和搭接长度为变化参数的63个该类接头拉伸试验，研究了试件的破坏形态、极限承载力、力-位移曲线和钢筋及套筒的应变.试件出现了套筒外钢筋拉断和钢筋与灌浆料滑移两种破坏形态，未出现已有约束对接接头文献中的灌浆料与筒壁拉脱及套筒被拉断的破坏情况.与单根钢筋相比，该类接头力-位移曲线、极限承载力接近，刚度稍差.相同钢筋，套筒外钢筋拉断试件，随着搭接长度增加，套筒的横向约束减弱；钢筋滑移的试件，随着钢筋直径的增加，套筒的横向约束增强.分析了套筒约束浆锚搭接与对接接头受力机理，表明对接接头对套筒材料抗拉及筒壁与灌浆料的抗滑移性能要求更高.给出搭接接头的力学模型，提出了接头的平均搭接粘结应力和临界搭接长度的计算公式.由于套筒约束接头的搭接长度大大减小，建议该接头的搭接长度为12.5倍的钢筋直径.
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| 关键词: 钢筋滑移 搭接长度 套筒环向应变 套筒约束 平均搭接应力 |
| DOI：10.11918/j.issn.0367-6234.2016.12.004 |
| 分类号:TU375 |
| 文献标识码:A |
| 基金项目: |
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| Experimental study of grouted sleeve lapping connectors varied in two factors under tensile load |
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YU Qiong, XU Zhiyuan, YUAN Weihang,Lü Xilin
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(Research Institute of Structural Engineering and Disaster Reduction, Tongji University, Shanghai 200092, China)
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| Abstract: |
| To improve the construction convenience of grouted splice connector, grouted sleeve lapping connector with independent intellectual property rights was put forward. A total of 63 specimens varied in bar diameter and lap length were tested under tensile load to study the mechanical properties of grouted sleeve lapping connector, which provides important scientific data for the application of the connector in precast concrete components. Failure modes, ultimate tensile capabilities, load-displacement curves and reinforcement and sleeve strains of the specimens were discussed. Bar fracture and bar-grout bond slip are the typical failure modes of the specimens, grout-sleeve bond failure and sleeve tensile fracture do not appear. Compared with the steel bar, the ultimate tensile capacity and the load-displacement curve of the connector are similar, while the stiffness is a bit lower. For specimens with the same bar diameter that failed by bar fracture, transverse confinement provided by the sleeve wall decreases as lap length increases. For specimens with bar-grout bond failure, bar diameter increase leads to an increase in confinement stress generated by the sleeve wall. The working mechanisms of grouted sleeve lapping connector and butting connector were analyzed. Compared with grouted sleeve lapping connector, sleeves with stronger tensile capacity and grout-sleeve with higher bond performance are needed to guarantee the working performance of grouted sleeve butting connector. The mechanical properties and mechanical model of grouted sleeve lapping connector were analyzed. Two equations were proposed to calculate the average lapping bond stress and critical lap length. Under confinement, the required lap length can be shortened greatly. The recommended lap length is 12.5 times bar diameter.
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| Key words: reinforcement bond-slip lap length sleeve hoop strain sleeve confinement average lapping bond stress |
