UHTCC/RC复合梁剪切性能试验研究

超高韧性水泥基复合材料(UHTCC)以其多重细密稳态开裂模式在宏观上展现出拉应变硬化特征,具有优异的裂缝控制能力,可用作修补材料。采用UHTCC替代部分受拉区混凝土对有腹筋UHTCC/RC复合梁进行了剪切性能研究。试验变量为UHTCC层厚度。结果表明:不同UHTCC层厚度的UHTCC/RC复合梁,其抗剪承载力均明显高于RC对比梁;即便配置较密集的箍筋,仍然无法阻止界面剥离,但可以避免界面剥离产生的荷载抖降;UHTCC能够限制和分散上层混凝土中的裂缝。最后,给出了UHTCC/RC复合梁在实际应用中的建议。

Experimental Study on Shear Behavior of UHTCC/RC Composite Beams

Ultra high toughness cementitious composites (UHTCC ) macroscopically presents tensile strain hardening char-acteristic because of its multiple fine steady cracking ,which has excellent crack control capacity ,and is suitable to be used as repair materials .The shear behavior of UHTCC/RC composite beams with web reinforcement is investigated by using UHTCC replacing partial concrete in tension region .The test variable is the thickness of UHTCC layer .The test re-sults show that the shear bearing capacity of UHTCC/RC composite beams with different thickness of UHTCC layer is ob-viously higher than that of RC beam .And although the use of stirrups is still impossible to completely prevent the inter-face from debonding ,and load drops caused by interface debonding can be effectively avoided .It is also observed that UHTCC can restrict and disperse the cracks in upper concrete .Finally ,some suggestions on the practical application of UHTCC/RC composite beams are provided .