(1 上海市建筑科学研究院有限公司, 上海 200032;2 上海市工程结构安全重点实验室, 上海 200032)

摘要: 为了进一步解决对历史建筑钢筋材料强度缺乏了解的问题,对历史文献进行了调研,并对上海某近代混凝土建筑改造工程现场截取的不同规格型号的钢筋进行了拉伸试验及里氏硬度试验. 结合历史文献调研结果及钢筋制造工艺、拉伸试验及里氏硬度试验结果,对近代混凝土建筑中实测钢筋里氏硬度进行统计分析,得到如下结论:在相当于我国当前标准的 HPB235 级和 HRB335 级钢筋之间尚存在屈服强度 275MPa 的钢筋;当采用表面硬度法对近代混凝土结构中的钢筋强度等级进行判别时,若实测钢筋里氏硬度代表值大于 400,可判别为 G40 级;若实测钢筋里氏硬度代表值小于 375 时,可判别为 G33 级;在两者之间时,建议取样检测或偏保守判别为 G33 级;G33级钢筋屈服强度可按 HPB235 级钢筋取值,G40 级钢筋屈服强度可按 275MPa 取值;扭钢属于冷扭钢筋,在进行承载力验算时扭钢的屈服强度可按 335MPa 取值.

关键词: 近代钢筋混凝土结构; 钢筋强度; 里氏硬度; 拉伸试验

中图分类号:TU375 文献标志码:A 文章编号:1002-848X(2022)03-0078-07

DOI:10. 19701 / j. jzjg. LS202013

Research on judging method of reinforcement strength in modern reinforced concrete structures

ZHENG Shiju1,2, BAI Xue1,2, JIANG Lixue1,2

(1 Shanghai Research Institute of Building Sciences Co., Ltd., Shanghai 200032, China;2 Shanghai Key Laboratory of Engineering Structure Safety, Shanghai 200032, China)

Abstract: In order to further solve the problem of lack of understanding of the strength of reinforcement in historicalbuildings, the historical documents were investigated, and the tensile test and Leeb hardness test of different specificationsof reinforcement intercepted from a modern concrete building reconstruction project in Shanghai were carried out. Based onthe investigation results of historical documents and the test results of reinforcement manufacturing technology, tensile testand Leeb hardness test, statistical analysis on the measured Leeb hardness of reinforcement in modern concrete buildingswas maked. The following conclusions are drawn: there are still 275MPa reinforcement with yield strength between HPB235grade and HRB335 grade reinforcement in China′s current standards;when the surface hardness method is used to judge thestrength grade of reinforcement in modern concrete structures, if the representative value of reinforcement′s Leeb hardnessis greater than 400, it can be judged as grade G40; if the representative value of reinforcement′s Leeb hardness is less than375, if it can be judged as grade G33; if between the two, it is recommended to take samples for testing or to identify it asG33 conservatively. The yield strength of grade G33 reinforcement can be taken as HPB235 reinforcement, and the yieldstrength of G40 reinforcement can be taken as 275MPa;the torsional steel belongs to cold-torstorsional reinforcement, andthe yield strength of the torsional steel can be calculated according to 335MPa when the bearing capacity is checked.

Keywords:modern reinforced concrete structures; reinforcement strength; Leeb hardness; tensile test

∗上海市科学技术委员会科研项目(19DZ1202400) ,上海市建筑科学研究院集团科研创新课题(KY10000038. 20190003) .

第一作者:郑士举,硕士,高级工程师,主要从事既有建筑检测评估与加固改造,Email:zsj85408048@ 163. com.

[引用本文] 郑士举,白雪,蒋利学. 近代钢筋混凝土结构的钢筋强度判别方法研究[ J] . 建筑结构,2022,52( 3) :78-84. ZHENG Shiju,BAI Xue,JIANG Lixue. Research on judging method of reinforcement strength in modern reinforcedconcrete structures[ J] . Building Structure,2022,52(3) :78-84.