【作者】 潘景龙； 金熙男； 胡忠君；

【Author】 Pan Jinglong Jin Xi’nan Hu Zhongjun (School of Civil Engineering Harbin Institute of Technology Harbin 150090)

【机构】 哈尔滨工业大学土木工程学院；

【摘要】 国内外许多学者根据FRP材料强度计算的约束强度和约束比,提出了不同形式的预测圆截面FRP约束混凝土强度的模型,其结果彼此存在较大差异。本文在分析了大量试验资料后认为试件破坏瞬时FRP产生的有效约束应力与上述约束强度存在不同程度的差距,导致现有模型未能正确体现FRP的约束效应。鉴于FRP强约束混凝土竖向应力超过核心混凝土强度后,它与环向缠绕FRP的拉应变(应力)间存在良好的线性关系,提出了适用于外包FRP方式,约束刚度比β_j在10～150范围内,用约束刚度比β_j来预测约束混凝土轴压应力和强度的新模型,以便在给定FRP容许拉应变条件下正确估计FRP约束混凝土实际应力和安全储备。更多还原

【Abstract】 According to the confined strength of concrete and confinement ratio, which were calculated based on the strength of FRP, many scholars proposed a variety of models which were set up to predict the FRP confined strength of circular cross section. But, the predicted results are different from each other. By analysis of many test results, the difference was found between the effective FRP confined stress at the disable moment of specimens and confined strength as mentioned above. This make existing models not reflect the effect of FRP confinement accurately. In terms of a desirable linear relationship between the tensile strain(stress) of FRP in hoop direction and the longitudinal stress of FRP sufficiently confined concrete which is above strength of unconfined concrete, a new model is proposed to predict the axial compressive stress and strength by confinement-stiffness ratio(β_j) in order to estimate the actual confined stress and safe reserving of FRP confined concrete in certain strain of FRP. This model is suitable to specimen wrapped with FRP and confinement-stiffness ratio(β_j) ranging between 10 and 150.更多还原