低周反复荷载下预应力CFRP筋-型钢/混凝土偏拉构件抗裂性能试验

Experiment on crack resistance of prestressed CFRP tendons-steel reinforced concrete eccentrically tensioned members under low-cyclic reversed loading

  • 摘要: 为研究预应力碳纤维增强树脂复合材料(CFRP)筋-型钢/混凝土(SRC)偏拉构件的抗裂性能,以不同的预应力张拉水平、偏心距、预应力筋类型及竖向拉力等参数制作了11个试件,并对其进行低周反复加载试验。结果表明:相比于普通SRC偏拉构件,预应力SRC偏拉构件的抗裂度和裂缝控制能力显著提升,其开裂荷载提高约1.5倍,抗裂性能与预应力张拉水平正相关,与偏心距负相关,预应力筋类型对开裂荷载影响不大。另外直径7 mm的预应力CFRP筋在控制构件裂缝数量方面强于直径15 mm的预应力精轧螺纹钢筋,适当增大竖向拉力可提高试件抗裂性能。参照现有理论和试验结果,推导出试件开裂荷载的计算公式,其计算结果与试验值吻合度较高。

     

    Abstract: In order to investigate the crack resistance of prestressed carbon fiber reinforced polymer (CFRP) reinforced steel concrete eccentrically tensioned members, eleven specimens were fabricated with different parameters such as eccentricity, level of prestress, type of prestressed tendons and vertical tension were tested under low cyclic reversed loading. The results show that the crack resistance and crack control ability of prestressed steel reinforced concrete (SRC) biased tensioning members are significantly improved compared with the ordinary SRC biased tensioning members, and the cracking load is increased by about 1.5 times. The crack resistance of prestressed SRC biased tensioning members is positively related to the prestress level, and negatively related to the eccentricity. The type of prestressed tendons has little effect on the cracking load. In addition, the 7 mm diameter prestressed CFRP tendons are stronger than the 15 mm diameter prestressed fine rolled threaded rods in controlling the number of cracks in the members, and the crack resistance of the specimens can be improved by increasing the vertical tensile force appropriately. According to the existing theory and test results, the calculation formula of cracking load is derived, and the calculated results are in good agreement with the test values.

     

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