箍筋锈蚀对钢筋混凝土梁承载机理影响的试验研究*
- 摘 要
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（1 昆明理工大学，昆明 650500； 2 中央大学，东京 1128551）
［摘要］以位移控制加载，进行了锈蚀钢筋混凝土梁的四点受弯加载试验。增大部分试件箍筋的间距，以研究严重锈蚀后箍筋剩余量较少情况下锈蚀钢筋混凝土梁的承载机理和破坏模式。通过纵筋的应变分布，计算各加载水平下纵筋与混凝土之间的粘结应力。试验表明，随着纵筋和箍筋的锈蚀，剪跨区域的平均粘结应力达到最大值后逐渐减小；锚固区域的平均粘结应力逐渐增大。锈蚀钢筋混凝土梁的承载机理为梁效应向拱效应转化过程中的复合梁拱效应状态，其转化程度取决于纵筋的锈蚀率和箍筋的剩余量。根据梁拱效应转化的程度，提出锈蚀钢筋混凝土梁承载机理的判断流程图。［关键词］箍筋; 锈蚀; 极限承载力; 承载机理; 拱效应; 梁效应; 复合梁拱效应中图分类号：TU375.1 文献标识码：A 文章编号：1002-848X(2016)06-0086-05
Experimental study on stirrup corrosion effect on the bearing mechanism of reinforced concrete beamsDong Wei1, Su Zhimin1, Yang Huashu1, Wu Liang1, Oshita Hideki2, Ye Jiabing1(1 Kunming University of Science and Technology, Kunming 650500, China; 2 Chuo University, Tokyo 112 8551, Japan)Abstract:Four-point static bending tests of the corroded reinforced concrete beams were carried out under displacement controlled loading. To investigate the bearing mechanism and the failure mode of the corroded reinforced concrete beams with plenty of seriously corroded stirrups, the stirrup spacing of some specimens was increased. The bond stress distribution between longitudinal rebar and concrete under various loading levels was calculated through strain distribution of longitudinal rebar. Experiments show that, with the increase of the corrosion of longitudinal rebar and stirrups, the average bond stress of the shear span region increases to a peak value and then decreases. The average bond stress of the anchorage region increases significantly. The bearing mechanism of the reinforced concrete corroded beams is the composite beam-arch effect state that is in the process of shifting from beam effect to arch effect, and the shifting extent depends on the corrosion ratio of longitudinal rebar and the remain mass of stirrups. Based on the shifting content of beam-arch effect, the judgment flowchart for bearing mechanism of corroded reinforced concrete beams was proposed.Keywords:stirrup; corrosion; ultimate bearing capacity; bearing mechanism; arch effect; beam effect; composite beam-arch effect
*国家自然科学基金资助项目（51569011，41462013，51269007），云南省级人才培养项目（KKSY201204157），国家级大学生创新训练计划（201410674002），云南省教育厅科学研究基金项目（2015Y072）。作者简介：董卫，博士，讲师，Email：touicn@163.com。
