玻璃钢/复合材料 ›› 2018, Vol. 0 ›› Issue (12): 11-15.

• 基础研究 • 上一篇    下一篇

疲劳荷载作用下FRP筋混凝土构件的裂缝宽度计算方法研究

孙理想, 李星, 杨子江   

  1. 兰州交通大学土木工程学院,兰州730070
  • 收稿日期:2018-06-28 出版日期:2018-12-28 发布日期:2018-12-28
  • 作者简介:孙理想(1984-),男,硕士,讲师,主要从事桥梁结构设计理论方面的研究,sunlx@mail.lzjtu.cn。
  • 基金资助:
    国家自然科学基金(51368031);中国铁路总公司科技研究开发计划资助项目(2017G010-C);甘肃省基础研究创新群体项目资助项目(1506RJIIA029)

CALCULATION METHOD FOR CRACK WIDTH OF FRP REINFORCED CONCRETE MEMBERS UNDER FATIGUE LOADING

SUN Li-xiang, Li Xing, YANG Zi-jiang   

  1. College of Civil Engineering, Lanzhou Jiaotong University, Lanzhou 730070, China
  • Received:2018-06-28 Online:2018-12-28 Published:2018-12-28

摘要: FRP筋混凝土构件具有承载力高、耐久性好等诸多优点,目前对FRP筋混凝土构件的抗弯性能研究已经相对较多,然而在实际工程应用中构件常常在重复荷载作用下工作,为了研究疲劳荷载作用下FRP筋混凝土构件的抗弯性能,首先研究了疲劳荷载作用下FRP筋混凝土构件裂缝宽度的开展规律;基于静力荷载作用下FRP筋混凝土构件裂缝宽度计算理论,通过引入相关参数修正得到了疲劳荷载作用下FRP筋混凝土构件的计算公式,并对修正的公式进行了验证。研究表明:FRP筋混凝土构件在疲劳荷载持续荷载作用下,内部会产生疲劳损伤,影响FRP筋与混凝土之间的粘结性能,使得构件整体刚度降低,较早地萌生疲劳裂缝,并且随着荷载作用周期以及作用次数的不断增加,构件裂缝宽度会呈现出逐渐增大的趋势,最终趋于一个稳定的变化范围;通过引入FRP筋与混凝土粘结滑移相关参数a以及受压区混凝土应变增大系数Nc,修正得到了疲劳荷载作用下FRP筋混凝土构件裂缝宽度的计算方法。

关键词: FRP筋混凝土构件, 疲劳荷载, 裂缝宽度, 计算方法

Abstract: FRP reinforced concrete members have many advantages, such as high bearing capacity, good durability and so on. At present, the bending performance of FRP reinforced concrete members is relatively more. However, in practical engineering applications, the components often work under repeated loads. In order to study the flexural performance of the FRP reinforced concrete members under fatigue load, the bending performance of the reinforced concrete members is studied. In this paper, the crack width of FRP reinforced concrete member under the action of fatigue load is studied. Based on the calculation theory of crack width of FRP reinforced concrete members under static load, the calculation formula of FRP reinforced concrete member under fatigue load is obtained by introducing the relevant parameters, and the modified formula is tested. The study shows that the fatigue damage of the FRP reinforced concrete member under the continuous load of fatigue load will result in the fatigue damage in the member, and the bond performance between the FRP reinforcement and the concrete, which makes the overall stiffness of the component lower, the early initiation of fatigue crack, and the increasing of the load cycle and the number of action times. The crack width will gradually increase, and eventually tend to a stable range of change. By introducing the parameter a of the bond slip of the FRP bar and concrete and the strain increasing coefficient of the concrete in the compression zone, the calculation method of crack width of FRP reinforced concrete members under fatigue loading is obtained.

Key words: FRP reinforced concrete member, fatigue load, crack width, calculation method

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