侵蚀环境下FRP条带加固锈蚀钢筋混凝土圆柱轴心受压试验

Experimental study on axial compression of corroded reinforced concrete columns strengthened with FRP strips under erosion environment

  • 摘要: 通过侵蚀环境下碳纤维增强聚合物(CFRP)复合材料条带和玻璃纤维增强聚合物(GFRP)复合材料条带加固锈蚀钢筋混凝土圆柱试验,分析了侵蚀环境对混凝土强度、纤维增强聚合物基复合材料加固锈蚀柱的极限荷载和荷载-轴向位移曲线的影响。结果表明,混凝土强度受冻融环境影响较大,受干湿环境影响较小;纤维增强聚合物(FRP)复合材料加固锈蚀柱的轴向极限荷载与冻融循环次数、钢筋锈蚀率及FRP复合材料种类有关,随冻融循环次数分别增加到25次、50次、75次,GFRP复合材料条带和CFRP复合材料条带加固锈蚀钢筋混凝土圆柱的轴向极限荷载分别降低了10.97%、13.37%、16.04%和5.95%、4.66%、4.33%;FRP复合材料加固锈蚀柱的刚度和耗能受侵蚀环境种类、侵蚀环境作用次数、锈蚀率及FRP复合材料种类的影响。在试验研究的基础上,通过理论分析侵蚀环境下混凝土强度损伤系数和锈蚀钢筋强度退化方程,提出了侵蚀环境下FRP复合材料条带加固锈蚀钢筋混凝土圆柱轴心受压承载力计算方法。

     

    Abstract: Through the test of corroded reinforced concrete columns which were strengthened with carbon fiber reinforced polymer (CFRP) composite strips and glass fiber reinforced polymer (GFRP) composite strips in the erosion environment, the influences of erosion environment on the concrete strength, the ultimate load and the axial load-displacement relationship curve of corroded and FRP strengthened concrete columns were analyzed. The result shows that the strength of the concrete is greatly affected by the freeze-thaw environment and is less affected by the dry and wet environment. The axial ultimate load of FRP reinforced damaged columns is related to the number of freeze-thaw cycles, the corrosion rate of steel bars and the type of FRP composite. With the increase of freeze-thaw cycles from 0 to 25, 50 and 75, the axial ultimate loads of corroded reinforced concrete columns strengthened with GFRP composite and CFRP composite strips are decreased by 10.97%, 13.37%, 16.04% and 5.95%, 4.66%, 4.33% respectively. The load-axial displacement curve of the FRP composite reinforced corrosion column reflects the stiffness and the energy consumption of the column, and both of which are affected by the type of erosion environment, the number of times of the erosion environment, the corrosion rate of steel bars and the type of FRP composite. Through the experimental research, the damage coefficient of concrete strength and the regression equation of the strength of corroded bar in the erosion environment were theoretically analyzed. A method for calculating the axial compression capacity of corroded reinforced concrete columns strengthened with FRP composite strips under erosion environment was presented.

     

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