钢筋混凝土界面剪力传递性能试验研究

Experimental study on shear transfer behavior along RC interface

以受剪钢筋配筋率、界面特性、加载方式及加载偏心为试验参数,对12个钢筋混凝土推剪试件进行试验研究。分析试件的破坏形态、滞回特性、承载力与刚度退化特性,研究各试验参数对界面受剪承载力的影响。结果表明:循环反复加载试件发生典型的剪切破坏;在文中试验参数下,影响界面受剪承载力的主要因素依次为界面特性、受剪钢筋配筋率、加载方式及加载偏心;循环反复荷载将引起界面受剪承载力降低,对整浇界面受剪承载力降低影响较小,而对新旧混凝土界面受剪承载力降低影响较大。根据试验结果并结合相关试验数据,对钢筋混凝土界面受剪承载力计算方法提出建议。通过与试验值及已有公式计算结果比较可知,建议计算式的计算结果与试验结果吻合较好。

Twelve push-off specimens were designed, constructed, and tested. Test variables included reinforcement ratio of shear reinforcement, interface preparation, loading method and eccentricity of applied load. The failure pattern, hysteretic characteristics and degradation characteristics of bearing capacity and stiffness were analyzed. The effect of each test variable on interracial shear capacity was studied. Results show that the failure pattern of test specimens under cyclic reversed loading is typical shear failure. The order of main factors influencing interfacial shear capacity is interface preparation, shear reinforcement ratio, loading method and loading eccentricity in turn based on test results. Cyclic reversed loading reduces interfacial shear capacity. The reduction is smaller for monotonic interfacial shear strength. But for new and existing concrete interfaces, the reduction is bigger and can not be neglected. Based on the test results and the available data, a calculation method for interfacial shear capacity of a RC member was proposed. The calculated results show good agreement with the test results on the basis of comparison with test values and calculated values of other calculation formula.