（1 北京工业大学工程抗震与结构诊治北京市重点实验室， 北京 100124; 2 中铁建设集团有限公司， 北京 100131）

［摘要］有关抗震设计和施工规范要求节点核心区浇筑与柱相同强度等级的混凝土从而形成传统节点，但这会产生支模困难、施工缝难以处理、施工质量不易保证等问题。节点核心区浇筑与梁板相同强度等级的混凝土，当梁柱混凝土强度相差超过2个等级时形成所谓的夹心节点，则可能解决这些问题，但其抗震性能尚不明确。为了研究夹心节点与传统节点抗震性能的区别，对2组4个分别相差3个与4个强度等级的传统节点与夹心节点进行了低周往复试验。试验结果表明，除梁柱相差4个强度等级的夹心节点发生节点区剪切破坏外，其余3个试件均发生梁端弯曲破坏；在中低轴压比条件下，当梁柱混凝土强度之比小于1-5时，节点区可直接采用与梁相同强度等级的混凝土浇筑；夹心节点的梁端承载力、梁纵筋粘结锚固能力、变形及耗能能力略低于传统节点。

［关键词］传统节点； 夹心节点； 抗震性能； 试验研究

中图分类号：TU398-7文献标识码：A文章编号：1002-848X(2016)24-0046-04

Experimental research on seismic performance of sandwich joint of spatial RC frame with floors

Qi Yue1, Yan Weiming1, Zhang Jiabin1,2, Hou Liqun1, Zhang Ruiyun1

(1 Key Laboratory of Earthquake Engineering and Structural Retrofit of Beijing, Beijing University of Technology，Beijing 100124, China； 2 China Railway Construction Group Co.， Ltd., Beijing 100131, China)

Abstract:In relevant seismic design and construction specifications, it′s required that concrete poured into core zone of joint should be in same strength grade as concrete poured into columns  to form the traditional joint. However it will produce problems as difficulty in formwork construction, difficulty in dealing with the construction seam, hard guarantee of construction quality etc. Concrete cast in the core zone of the joint should have the same strength grade as that cast in beam and slab, but it will form so-called sandwich joint if the strength grade of concrete cast in beam and column is more than 2 grades, and it may solve these problems. The seismic performance of sandwich joint is not clear. In order to study the difference between the seismic performances of the sandwich joint and the traditional joint, low cyclic loading tests were conducted on 4 specimens of 2 groups with differences in 4 or 5 levels of strength grades between the traditional joints and the sandwich joints. The experimental results show that, shear failure happens in joint zone of sandwich joint with 4 levels of difference in strength grade of concrete of the beam and column, and the other three specimens have bending failure in beam ends. Under medium-low axial compression ratio, when concrete strength ratio of beam and column is less than 1-5, the joint zone can be directly cast using the concrete with the same strength grade as that in beam concrete. Bearing capacity of the beam ends, bond and anchorage capacity of beam longitudinal reinforcement, deformation and energy dissipation capacity of the sandwich joint are slightly lower than those of the traditional joint.

Keywords:traditional joint; sandwich joint; seismic performance; experimental research

*国家自然科学基金项目(51378039，51421005)，教育部学术创新团队“土木抗震减震”和北京市属高等学校创新团队建设与教师职业发展计划项目资助。

作者简介：齐越，硕士，Email: 117962696@qq.com。