(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: 预制混凝土柱采用钢筋套筒灌浆连接时,在连接处形成套筒刚域,将对钢筋的受力状态产生一定程度的影响。 通过 1 个现浇混凝土柱、1 个无灌浆缺陷预制混凝土柱、5 个带不同程度灌浆缺陷预制混凝土柱、2 个灌浆缺陷注射补灌修复预制混凝土柱的低周反复荷载试验,研究了上述各种情况下的钢筋屈服特征及其对塑性铰形成的影响。 研究结果表明:预制混凝土柱采用钢筋套筒灌浆连接时,套筒刚域的存在导致钢筋出现应变集中现象,塑性铰集中在底部接缝位置;当灌浆缺陷增大到一定程度后,柱底部接缝钢筋不再屈服,塑性铰不再形成;带灌浆缺陷预制混凝土柱通过注射补灌修复后,预制柱的钢筋屈服特征可以恢复到无灌浆缺陷状态。 研究结果可为优化预制混凝土柱钢筋套筒灌浆连接的计算理论提供依据。

关键词: 套筒灌浆缺陷; 预制混凝土柱; 钢筋屈服; 塑性铰

中图分类号:TU758. 14 文献标志码:A 文章编号:1002-848X(2022)13-0021-05

DOI:10. 19701 / j. jzjg. 20210880

Study on influence of sleeve grouting defects on rebar yield characteristics of precast concrete column

GAO Rundong, LI Xiangmin, XIAO Shun, WANG Zhuolin, ZHANG Fuwen, XU Qingfeng

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

Abstract: When precast concrete column is connected by sleeve grouting with rebars, the sleeve rigid region is formed at the joint, which will affect the stress state of rebars to a certain extent. Through the low-cycle reversed loading tests of one cast-in-place concrete column, one precast concrete column without grouting defect, five precast concrete columns with different degree of grouting defects and two precast concrete columns with grouting defects repaired by supplementary grouting, the reinforcement yield characteristics under above various conditions and their effects on plastic hinge formation were studied. The study results show: when the precast concrete column is connected by sleeve grouting with rebars, the reinforcement strain concentration phenomenon is caused by the existence of sleeve rigid region, and the plastic hinge is concentrated at the bottom joint position; with the grouting defect increased to a certain extent, the rebars at the bottom joint of the column no longer yield, and the plastic hinge no longer forms; after the precast concrete column with grouting defect is repaired by injecting for supplementary grouting, the rebars yield characteristics of the precast concrete column can be restored to the state without grouting defect. The research results can provide a basis for optimizing the calculation theory of precast concrete column connected by sleeve groutingwith rebars.

Keywords:sleeve grouting defect; precast concrete column; rebar yield; plastic hinge