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(上海市建筑科學(xué)研究院有限公司 上海市工程結(jié)構(gòu)安全重點(diǎn)實(shí)驗(yàn)室, 上海 200032)

摘要: 預(yù)制混凝土柱采用鋼筋套筒灌漿連接時(shí),在連接處形成套筒剛域,將對鋼筋的受力狀態(tài)產(chǎn)生一定程度的影響。 通過 1 個(gè)現(xiàn)澆混凝土柱、1 個(gè)無灌漿缺陷預(yù)制混凝土柱、5 個(gè)帶不同程度灌漿缺陷預(yù)制混凝土柱、2 個(gè)灌漿缺陷注射補(bǔ)灌修復(fù)預(yù)制混凝土柱的低周反復(fù)荷載試驗(yàn),研究了上述各種情況下的鋼筋屈服特征及其對塑性鉸形成的影響。 研究結(jié)果表明:預(yù)制混凝土柱采用鋼筋套筒灌漿連接時(shí),套筒剛域的存在導(dǎo)致鋼筋出現(xiàn)應(yīng)變集中現(xiàn)象,塑性鉸集中在底部接縫位置;當(dāng)灌漿缺陷增大到一定程度后,柱底部接縫鋼筋不再屈服,塑性鉸不再形成;帶灌漿缺陷預(yù)制混凝土柱通過注射補(bǔ)灌修復(fù)后,預(yù)制柱的鋼筋屈服特征可以恢復(fù)到無灌漿缺陷狀態(tài)。 研究結(jié)果可為優(yōu)化預(yù)制混凝土柱鋼筋套筒灌漿連接的計(jì)算理論提供依據(jù)。

關(guān)鍵詞: 套筒灌漿缺陷; 預(yù)制混凝土柱; 鋼筋屈服; 塑性鉸

中圖分類號:TU758. 14 文獻(xiàn)標(biāo)志碼:A 文章編號: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