摘要
HRB500钢筋、HRB600钢筋已分别纳入《钢筋混凝土结构设计规范》(GB50010-2010)和《钢筋混凝土用钢第2部分:热轧带肋钢筋》(GB/T 1499.2-2018)。为考察HRB500钢筋、HRB600钢筋作纵筋的混凝土连续梁弯矩调幅性能,完成了24根两跨连续梁试验。试验结果表明,由于HRB500和HRB600钢筋的屈服强度明显高于HPB235和HRB335钢筋,试验梁中支座控制截面的弯矩调幅不只发生在塑性铰形成之后,在受拉区混凝土进入塑性、经历开裂和裂缝发展直至中支座控制截面受拉纵筋屈服这一较长的塑性发展过程中也存在一定的弯矩调幅。分塑性铰形成前后两阶段对试验梁中支座控制截面弯矩调幅进行考察,第一阶段弯矩调幅幅度βI介于15.28%～24.21%,第二阶段弯矩调幅幅度βII介于6.91%～30.30%。发现随着受拉纵筋屈服强度的提高,βI增大、βII减小;随着相对受压区高度的增大,βI和βII均减小;随着中支座宽度的增大,βI和βII均增大。基于试验数据建立考虑各关键参数影响的两阶段弯矩调幅系数计算公式。
HRB500 and HRB600 steel bars have been adopted by ‘Code for design of concrete structures’(GB50010-2010) and ‘Steel for the reinforcement of concrete-Part 2: Hot rolled ribbed bars’(GB/T 1499.2-2018). In order to investigate the moment redistribution in continuous reinforced concrete beams with HRB500 and HRB600 steel bars as tensile longitudinal bars, 24 two-span continuous beams were tested in this study. The test results showed that the moment redistribution occurred not only after the formation of plastic hinge but in the process from plastic development of the tensile concrete to the formation of the plastic hinge. The moment redistribution was investigated in two stages, namely, before and after the appearance of the plastic hinge. The first-stage moment redistribution(βI) was between 15.28%~24.21% and the second-stage moment redistribution(βII) was between 6.91%~30.3%. It was found that the increase in the yield strength of tensile longitudinal steel bars led to an increase in βI but a decrease in βII. Moreover,βI and βII increased with the increase in the width of the mid-support and the decrease in the relative depth of the compressive zone. Formulas for the moment redistribution of two stages considering the effects of the key factors were proposed based on the test results.
作者
郑文忠
李玲
王英
ZHENG Wen-zhong;LI Ling;WANG Ying(Key Laboratory of Disaster and Control in Structural Engineering of China Ministry of Education, Harbin Institute of Technology, Harbin 150090, China)
出处
《工程力学》
EI
CSCD
北大核心
2019年第3期79-94,共16页
Engineering Mechanics
基金
教育部博士点基金资助项目(20132302110064)
国家自然科学基金项目(51678190
51378146)
