模拟碱骨料反应引起的箍筋端部锚固退化对钢筋混凝土梁受剪性能的影响  

Simulation of Influence of End Anchorage Degradation of Stirrups Caused by Alkali Aggregate Reaction on Shear Performance of Reinforced Concrete Beams

作　　者：赵朋飞 薛昕[1] 杨成[1] ZHAO Pengfei;XUE Xin;YANG Cheng(School of Architecture and Civil Engineering,Xiamen University,Xiamen 361005,Fujian,China)

机构地区：[1]厦门大学建筑与土木工程学院,福建厦门361005

出　　处：《上海交通大学学报》2021年第6期681-688,共8页Journal of Shanghai Jiaotong University

基　　金：福建省自然科学基金面上项目(2018J01086);厦门市交通基础设施智能管养工程技术研究中心开放基金资助项目(TCIMI201804);国家重点研发计划(2016YFC0701106)。

摘　　要：采用人工方法模拟碱骨料反应(AAR)引起的箍筋下端锚固退化,通过三点加载实验和数值模拟对钢筋混凝土(RC)梁受剪性能展开研究.结果表明:和完好梁相比,剪跨区内箍筋下端锚固退化降低了RC梁的受剪承载力,且降低程度随局部黏结失效范围的增大而趋于明显.端部锚固退化导致的箍筋抗剪作用减小以及斜裂缝间骨料咬合承担剪力降低是承载力下降的主要原因.基于模拟箍筋应变的承载机制定量评价结果表明,箍筋下端锚固退化同时降低了混凝土承担剪力V_(c)以及箍筋承担剪力V_(s),但V_(s)降幅较V_(c)更为显著.This paper conducted a three-point loading experiment and analytical investigations on the shear performance of reinforced concrete(RC)beams with anchor defect at the lower end of stirrups.In the experiment,artificial methods were used to simulate the anchor degradation of the lower end of the stirrup caused by the alkali-aggregate reaction(AAR).The results show that,compared with the sound beams,the anchorage degradation of stirrups reduces the shear capacity of RC beams,and the degree of reduction becomes more pronounced with the increase of the local bond degradation area.The decrease in shear capacity is thought to be attributed to the reduction of the shear contribution by the stirrups and the reduction of the shear resistance by interlock action of coarse aggregate between diagonal cracks.The quantitative evaluation of shear contribution based on the computed stirrup strains confirms that the anchorage defect at the lower end of the stirrup reduces both the shear contribution V_(c) by concrete and V_(s) by stirrups,and the reduction of V_(s) is more significant than V_(c).

关 键 词：钢筋混凝土梁 碱骨料反应 箍筋端部锚固退化 受剪性能 有限元数值模拟 

分 类 号：TU375.1[建筑科学—结构工程]