Research on Microstructure and Mechanical Properties of Cold-Rolled Threaded Prestressed Rebars for Prefabricated Piers of Xiangan Bridge
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摘要: 结合厦门市翔安大桥装配式墩台节段预应力系统连接设计,对预应力连接系统中冷滚压螺纹预应力钢筋的力学性能开展研究。进行了75 mm直径冷滚压螺纹预应力钢筋横截面组织分析、单轴拉伸试验及疲劳性能试验研究。研究表明:75 mm直径冷滚压螺纹预应力钢筋横截面组织存在一定不均匀性,调质热处理工艺具有改进空间;冷滚压螺纹预应力钢筋的单轴拉伸应力-应变曲线无屈服平台;兼顾计算效率和计算精度,建议设计阶段结构计算模型中冷滚压螺纹预应力钢筋采用多折线模型进行计算,并且正常使用阶段,钢筋设计要求的张拉应力上限低于屈服点σ0.2;改善调质热处理参数可有效提高冷滚压螺纹预应力钢筋的疲劳性能。Abstract: Based on the connection design of the prestressed system for the prefabricated piers of Xiangan Bridge in Xiamen City, the mechanical properties of cold-rolled threaded prestressed rebars in the prestressed connection system were studied. The cross-sectional organization analysis, uniaxial tensile test, and fatigue performance test of 75 mm diameter cold-rolled threaded prestressed rebars were carried out. The results showed that there was some inhomogeneity in the cross-sectional organization of 75 mm diameter cold-rolled threaded prestressed rebars, and the heat treatment process still could be improved; the uniaxial stress-strain curve of cold-rolled threaded prestressed rebars had no yield platform; considering the efficiency and accuracy of calculation, it was suggested that the multi-fold model should be adopted to calculate the cold-rolled threaded prestressed rebars in the structural calculation model at the design stage. Under normal use conditions or frequently encountered loads, the design requirements for the upper limit of rebars should be lower than the yield point σ0.2; improving the heat treatment parameters could effectively improve the fatigue performance of cold-rolled threaded prestressed rebars.
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Key words:
- prefabricated piers /
- prestressed rebar /
- large diameter /
- cold rolling /
- microstructure /
- mechanical properties
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[1] 朱万旭, 覃荷瑛, 甘国荣, 等.港珠澳大桥节段预制桥墩高强钢筋联接锚固体系的关键技术研究[J]. 铁道学报, 2017(5):118-123. [2] 黄豪, 唐小兵, 张开银, 向木生.竖向预应力作用效果的数值模拟与预应力损失的试验研究[J]. 武汉理工大学学报(交通科学与工程版), 2007, 31(5):922-924. [3] 卢秀春, 金贺荣. 不锈钢筋表面滚压加工工艺参数设计与研究[J]. 机械设计, 2007, 24(2):39-41. [4] 朱万旭, 李明霞. 港珠澳大桥桥墩拼接用大直径螺纹钢筋应力腐蚀断裂试验研究[J]. 公路, 2020(10):112-117. [5] 崔怀俊, 盛剑. 大直径高强螺纹钢筋在港珠澳大桥预制墩台中的应用[J]. 中国港湾建设, 2017, 37(6):77-80. [6] 郭旭东. 港珠澳大桥承台墩身工厂化预制施工技术[J]. 桥梁建设, 2014, 44(2):107-111. [7] YOSHIMOTO I. The rolling pressure of the flat die type thread rolling machine[J]. Bulletin of Jsme, 2008, 2(7):495-499. [8] 韩林.高强度螺栓滚压螺纹工艺研究[D]. 上海:上海交通大学,2018. [9] SONG J L, LIU Z Q, LI Y T. Cold rolling precision forming of shaft parts:theory and technologies[M]. Beijing:National Defense Industry Press, 2013. [10] 冯鹏,强悍霖,叶列平. 材料、构件、结构的"屈服点"定义与讨论.[J] 工程力学,2017,34(3):36-46. [11] 中华人民共和国国家质量监督检验检疫总局.金属材料拉伸试验第 1部分:室温试验方法:GB/T 228.1-2010[S]. 北京:中国标准出版社, 2011. [12] RAMBERG W, OSGOOD W R. Description of stress-strain curves by three parameters[R]. Washington:National Advisory Committee for Aeronautics, TN 902, 1943. [13] ARRAYAGO I, REAL E, GARDNER L. Description of stress-strain curves for stainless steel alloys[J]. Materials and Design, 2015, 87(24):540-552. [14] 施刚,朱希. 高强度结构钢材单调荷载作用下的本构模型研究[J]. 工程力学,2017,34(2):50-59. [15] 许世杰,董满生,胡宗军, 等. 42CrMo钢疲劳试验研究[J]. 合肥工业大学学报,2008,31(9):1506-1508.
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