无腹筋GFRP筋混凝土梁抗剪性能试验

Shear Behavior Test of GFRP-reinforced Concrete Beams Without Stirrups

对一组无腹筋玻璃纤维增强塑料(Fiber Glass-reinforced Plastics,GFRP)筋混凝土梁的抗剪性能进行了试验研究,所有试验梁均为三分点加载,将6根试验梁按有效配筋率分为3组,每组包括1根钢筋混凝土梁和1根GFRP筋混凝土梁,且所有试验梁均为斜拉破坏;分析了试验梁的荷载-挠度关系、裂缝开展及抗剪承载力,并将各FRP筋设计规范或指南的抗剪承载力预测值与试验结果进行对比。结果表明:有效配筋率相同的钢筋混凝土梁和GFRP筋混凝土梁具有相近的抗剪承载力;修正的CAN/CSA-S6-06抗剪承载力预测结果与试验结果符合度最高,而ACI 440.1R-06的预测结果过于保守;建议的FRP筋混凝土梁抗剪承载力公式提高了承载力预测精度。

Authors studied the shear behavior of GFRP-reinforced concrete beams without stirrups by test.All beams subjected to four-point loading.The test variable was effective reinforcement ratio.The test beams included three beams reinforced with steel bars and three beams reinforced with GFRP bars.All the test beams appeared to diagonal tension failure.Authors analyzed relation of load and mid-span deflection,cracking behavior and shear strength of tested beams.Predicted values of shear strength recommended by design code of FRP bar were compared with test values.Results show that beams which are designed to have the same effective reinforcement ratio exhibit the similar shear strength regardless of reinforcement type,i.e.steel or GFRP.Predicted results of the modified CAN/CSA-S6-06 shear strength agree well with test results,whereas predicted results of the ACI 440.1R-06 is very conservative.Shear strength formula of the proposed FRP-reinforced concrete beam can be used to improve predicted precision of shear strength.