钢筋钢丝网砂浆加固混凝土圆柱的抗轴压性能

AXIAL COMPRESSION PERFORMANCE OF CONCRETE COLUMNS STRENGTHENED BY STEEL BAR AND WIRE MESH MORTAR

  • 摘要: 为大幅度提高加固效率,提出用钢筋钢丝网砂浆加固混凝土圆柱的思路。分别用钢筋钢丝网(SW)、钢筋网(S)、单一纤维复合材料(FRP)和混杂纤维复合材料(HFRP)加固混凝土圆柱共36根,进行轴压对比试验,探讨不同加固方法对试件承载能力和延性的影响。结果显示:SW加固柱保护层砂浆剥落与内部核心混凝土破坏几乎同时发生;且保护层砂浆裂缝间距基本与钢丝网格间距相等(11mm左右),因而裂缝又多又密;故SW加固柱与S加固柱相比,在承载力提高30%的前提下,延性仍达S加固柱的2倍左右。FRP或HFRP加固柱的承载力提高幅度最大,但两种加固柱的延性和变形能力明显低于SW加固柱。该文给出了SW加固混凝土圆柱的极限承载力计算公式。

     

    Abstract: In order to increase the strengthening efficiency, a new method to strengthen concrete columns with steel bar and wire mesh mortar is proposed here. A total of 36 circular concrete columns were strengthened, using steel bar and wire mesh (SW), steel bar (S), sole fiber reinforced polymer (FRP) and hybrid fiber reinforced polymer (HFRP) respectively. Experimental study was performed under axial compression to investigate the influence of the different strengthening methods on the load carrying capacity and ductility. The experiment results showed that, the peeling of the mortar cover and the crushing of the core concrete happened almost simultaneously for the SW strengthened columns. The mortar cover crack spacing was basically equal to the wire mesh spacing, leading to the occurrence of many small cracks. As a result, on the premise that the ultimate load of the SW columns increased 30% compared with the S columns, the ductility of the SW columns was still about twice as that of the S columns. Although the increase of the load bearing capacities of FRP or HFRP strengthened columns was higher than that of SW or S strengthened columns, the ductility and deformation capacity of FRP or HFRP strengthened columns were obviously lower than those of SW columns. The formula of the ultimate load of SW mortar strengthened concrete columns was then proposed.

     

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