高延性混凝土加固钢筋混凝土梁受剪性能试验研究及承载力计算

EXPERIMENTAL STUDY ON SHEAR BEHAVIOR AND CAPACITY PREDICTION OF RC BEAMS STRENGTHENED WITH HIGH DUCTILE CONCRETE

为研究高延性混凝土(HDC)加固钢筋混凝土梁的受剪性能,该文对7根HDC加固梁及4根未加固梁进行静力试验,研究剪跨比、配箍率、加固层厚度和加固层附加箍筋对钢筋混凝土梁破坏形态、荷载-挠度曲线、受剪承载力以及裂缝的影响。结果表明:采用HDC面层对钢筋混凝土梁进行受剪加固,可以显著提高梁的受剪承载力;HDC面层可以代替部分箍筋的受剪作用,改善钢筋混凝土梁的剪切破坏形态;加固试件在达到极限位移之后,试件的完整性较好,剩余承载力较高。基于试验结果,利用桁架-拱模型,提出了HDC加固钢筋混凝土梁的受剪承载力计算公式,计算值与试验值吻合较好。

In order to study the shear response of reinforced concrete(RC)beams strengthened with high ductile concrete(HDC)jacketing layer,7 HDC jacketed RC beams and 4 non-strengthened RC beams were designed.The failure modes,load-deflection curves,shear capacities and cracks of the beams with different shear span ratios,stirrup ratios,thickness of HDC jacket and stirrups in HDC jacket were studied by static tests.The test results show that the HDC jacket can significantly improve the shear capacity of the beams.The HDC jacket can share partially shear loads which were taken by stirrups,and improve the shear failure pattern.After the ultimate displacements were reached,beams strengthened with HDC jacket exhibit good integrity and high residual bearing capacity.A formula based on the truss-arch model for calculating the shear capacity of beams strengthened with HDC jacket is proposed,and the calculated results are in good agreement with the test results.