高延性混凝土加固RC梁抗剪性能试验研究

为利用高延性混凝土（HDC）良好的拉伸和剪切变形能力，提高无腹筋钢筋混凝土梁的受剪性能，该文通过对9根HDC加固梁、1根高性能复合砂浆加固梁及3根未加固梁进行静力试验，研究剪跨比、加固层厚度和加固层是否配置箍筋对梁破坏形态、受剪承载力及变形能力的影响。结果表明:采用HDC面层对无腹筋梁进行抗剪加固，可以显著提高梁的抗剪承载力和变形能力；HDC面层可代替部分箍筋的抗剪作用，改善无腹筋梁的剪切破坏形态，并提高梁的剪压比限值；HDC加固层越厚，其受剪承载力和变形能力提高越明显，但加固层厚度较大时，需采用措施防止HDC面层间发生剥离破坏；HDC面层配置附加箍筋，可进一步提高试件的受剪承载力和耐损伤能力。基于试验结果，该文提出了HDC加固试件的受剪承载力计算公式，其计算值与试验结果吻合较好。

EXPERIMENTAL STUDY ON THE SHEAR BEHAVIOR OF RC BEAMS REINFORCED BY HIGH DUCTILE CONCRETE

To study the shear capacity of reinforced concrete(RC) beams without stirrups, nice RC beams with high ductile concrete(HDC) jacket, one RC beam with high-performance composite mortar jacket and three RC beams with no extra reinforcement were tested. The failure mode, shear capacity and deformability of all beams were studied for different shear span ratios and thickness of HDC jacket, and with or without stirrups in the HDC jacket. The test results showed that the HDC jacket can significantly improve the shear capacity and deformability of the beams, and can partially substitute stirrups by improving the shear failure form and increasing the threshold of the shear pressure ratio of the test beams. The thicker the HDC jacket, the more significant the improvement in the shear capacity and deformability. However, measures should be taken to prevent peeling damage when the HDC jacket is becoming too thick. Configuring stirrups in the HDC jacket can further improve the shear capacity and damage resistance ability of the strengthened beams. A formula was proposed to calculate the shear capacity of the beams, and the calculated values agree well with the test values.