学术论文

      钢筋混凝土销栓作用的疲劳承载性能试验研究

      Experimental study on mechanical properties of dowel bar embedded in concrete under fatigue loads

      摘要:
      为研究钢筋销栓作用的疲劳承载性能,制作了9个钢筋混凝土试件分别进行静载试验和疲劳加载试验。试件共分为2组,首先通过6个试件的静载试验确定销栓作用的极限承载力,其钢筋直径分别为12,20和25 mm;然后通过3个试件的疲劳加载试验来研究疲劳荷载作用下销栓作用承载性能的衰减特征及疲劳破坏形态。试验结果表明,在疲劳加载的过程中,疲劳损伤的积累会降低销栓作用的承载能力。在正常使用状态下,即极限承载力的55%,随着疲劳循环次数的增加,销栓作用的破坏模式会发生转化。疲劳破坏形态表现为钢筋的瞬时断裂,其疲劳寿命由钢筋和混凝土的材料性能所决定。基于试验结果,可以将钢筋销栓作用的疲劳破坏过程分为2个阶段,分别为损伤积累阶段和瞬时断裂阶段。
      Abstract:
      To investigate the mechanical properties of a dowel action under fatigue loads, nine reinforced concrete specimens were fabricated, and the monotonic and fatigue loadings were performed on these specimens, respectively. All of these specimens were divided into two series. Six specimens in SeriesⅠwith different bar diameters of 12, 20 and 25 mm were subjected to monotonic loads and were used to confirm the ultimate bearing capacity. The remaining three specimens in SeriesⅡwere subjected to fatigue loads and were designed to investigate the attenuation character of dowel action and the fatigue failure modes. The test results show that the accumulated fatigue damage due to fatigue loads can reduce the ultimate bearing capacity of specimens. With the increase in fatigue loads, the failure mode can transform to fatigue rupture of the dowel bar under the serviceability loading state, i. e. 55% of the monotonic capacity. The fatigue life is determined by the fatigue properties of steel and concrete. Based on the test data, the failure process of dowel action can be divided into two stages: the accumulation of fatigue damage and the fatigue rupture of dowel bar.
      作者: 李鹏飞 [1] 安雪晖 [1] 何世钦 [2] 陈宸 [2]
      Author: Li Pengfei [1] An Xuehui [1] He Shiqin [2] Chen Chen [2]
      作者单位: 清华大学水沙科学与水利水电工程国家重点实验室,北京,100084 北方工业大学土木工程学院,北京,100144
      年,卷(期): 2016, 32(4)
      分类号: TU312
      在线出版日期: 2017年2月14日
      基金项目: The Fund of the National Key Laboratory in China,the National Key Technology R& D Program of China