- 摘 要
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(上海市建筑科學研究院有限公司 上海市工程結構安全重點實驗室, 上海 200032)
[摘要]通過14組42個鋼筋套筒灌漿連接接頭試件的單向拉伸試驗,研究了水泥凈漿替代灌漿料、混凝土凈漿(試驗中用水泥砂漿模擬)包裹鋼筋、使用過期灌漿料、使用高水灰比灌漿料、灌漿時間滯后共5種非正常灌漿對鋼筋套筒灌漿連接接頭受力性能的不利影響。研究表明:水泥凈漿代替灌漿料、水泥砂漿包裹鋼筋厚度超過鋼筋肋高、灌漿料水灰比達到正常水灰比的1.35倍及以上等異常情況下,鋼筋套筒灌漿連接接頭試件單向拉伸性能均不能滿足《鋼筋套筒灌漿連接應用技術規程》(JGJ 355—2015)要求;在加載過程中,如果鋼筋發生屈服,無論是接頭外鋼筋被拉斷情況,還是鋼筋未斷情況,均是接頭外鋼筋發生屈服,接頭內鋼筋一般不再屈服?;谠囼灲Y果,對實際工程用灌漿料及其灌漿工藝提出了具體建議,以期提高裝配式混凝土結構鋼筋套筒灌漿的質量。
[關鍵詞]非正常灌漿;鋼筋套筒灌漿連接;高水灰比;單向拉伸性能;灌漿料
中圖分類號:TU758-14文獻標識碼:A文章編號:1002-848X(2021)05-0117-05
Experimental study on influence of abnormal grouting on mechanical properties of steel rebar sleeve grouting splicing joint
GAO Rundong, XIAO Shun, LI Xiangmin, WANG Zhuolin, LIU Hui, XU Qingfeng
(Shanghai Key Laboratory of Engineering Structure Safety, Shanghai Research Institute of Building Sciences Co., Ltd., Shanghai 200032, China)
Abstract:Through the uniaxial tensile test of 14 sets of 42 steel rebar sleeve grouting splicing joint specimens, the adverse effects of five kinds of abnormal grouting on the mechanical properties of steel rebar sleeve grouting splicing joints were studied, which included pure cement grouting replacing of grouting material, pure concrete grouting (simulated with cement mortar in the test) covering steel rebar, using expired grouting material, using high water-cement ratio grouting material and lagging grouting time. Research shows that the uniaxial tensile performance of steel rebar sleeve grouting splicing joint specimen can′t satisfy the requirements of the standard Technical specification for grout sleeve splicing of rebars(JGJ 355—2015) under such abnormal conditions as pure cement grouting replacing of grouting material, the thickness of the reinforcement coated with cement mortar exceeding the height of the reinforcement rib, and the water-cement ratio of grouting material reaching 1.35 times or more of the normal water-cement ratio. During the loading process, if the steel rebar yields, the steel rebar outside the joint yields and the steel rebar inside the joint generally no longer yields, whether the steel bar outside the joint is broken or not. Based on the test results, specific suggestions were put forward for grouting materials and grouting construction in actual project, so as to improve the steel rebar sleeve grouting quality for prefabricated concrete structures.
Keywords:abnormal grouting;steel rebar sleeve grouting splicing joint;high water-cement ratio;uniaxial tensile property;grouting material
*上海市科委社發領域課題(15DZ1203506,16DZ1201805,18DZ1205705),住房和城鄉建設部研究開發項目(2017-K9-043)。
作者簡介:高潤東,博士,正高級工程師,Email: grdong_1@163.com;通信作者:李向民,博士,教授級高工,Email: 13601902634@163.com。