EVALUATION OF SHEAR CAPACITY OF REINFORCED CONCRETE MEMBERS WITH RUPTURED SHEAR REINFORCEMENT DUE TO ASR DAMAGE

近年来，日本有报道称，由于ASR膨胀较大，桥墩T形梁中的箍筋和纵筋在弯角处发生断裂。因此，有必要弄清箍筋在弯角处断裂的梁的抗剪机理，以评估其剩余抗剪能力。本文研究了混凝土膨胀以及箍筋的粘结和锚固特性对抗剪性能的影响。为了评价断裂钢筋的粘结和锚固性能，还对ASR损伤混凝土的粘结强度进行了检测。试验结果表明，箍筋的断裂对钢筋混凝土梁的抗剪承载力有较大的影响。然而，影响的程度在很大程度上取决于ASR损伤混凝土中断裂箍筋的锚固特性。

In recent years, it is reported in Japan that stirrups, as well as longitudinal steels, in T-shaped beams of bridge piers were ruptured at their bent corners mainly due to large ASR expansion. Therefore, it is essential to make clear the shear resistant mechanism of the beams, in which the stirrups are ruptured at the bent corner, in order to evaluate their residual shear capacity.In this study, the effects of expansion of concrete as well as bond and anchorage characteristics of stirrups on shear behaviour are investigated. Bond strength of ASR damaged concrete is also examined in order to evaluate the bond and anchorage characteristics of ruptured steels.From the test results, it is found that rupture of stirrups has relatively large influence on shear capacity of reinforced concrete beams. However, the degree of the influence depends largely on the anchorage characteristics of ruptured stirrups in ASR damaged concrete.