配筋超高性能混凝土梁受剪性能研究  

Study on shear behavior of reinforced ultra-high performance concrete beams

作　　者：马恺泽[1] 马煜东 邢国华[1] 刘伯权[1] MA Kaize;MA Yudong;XING Guohua;LIU Boquan(Department of Civil Engineering,Chang’an University,Xi’an 710064,China)

机构地区：[1]长安大学建筑工程学院,陕西西安710064

出　　处：《建筑结构学报》2022年第12期179-188,共10页Journal of Building Structures

基　　金：国家自然科学基金项目(51868073)。

摘　　要：为了研究配筋超高性能混凝土梁的受剪性能,对1根配筋高强混凝土梁和8根配筋超高性能混凝土梁进行了受剪性能试验,主要变化参数包括剪跨比、钢纤维体积掺量和配箍率等。试验结果表明:所有梁的破坏模式均为剪切破坏,与配筋高强混凝土梁相比,配筋超高性能混凝土梁裂缝的发展更充分、宽度更小、分布更密集;钢纤维体积掺量和配箍率的增大均会提高梁的刚度、变形能力和承载力,并延缓其刚度退化速率;剪跨比的增加虽然可以提高梁的变形能力,但是降低了其承载力和刚度;混凝土开裂后,钢纤维可以“桥接”裂缝,与箍筋共同承担裂缝处的拉力,延缓箍筋应变的发展。最后,基于修正压力场理论,提出了配筋超高性能混凝土梁受剪承载力计算方法,并与法国AFGC-Setra 2013和韩国KCI-2012中建议的计算方法进行了对比,结果表明,建立的计算方法可以准确地预测配筋超高性能混凝土梁的受剪承载力。In order to investigate the shear behavior of reinforced ultra-high performance concrete(UHPC) beams, one high-strength concrete(HSC) beam and eight UHPC beams were tested. The main test variables were the shear span ratio, volume of steel fibers and stirrup ratio. The test results show that all beams display a shear failure mode. Compared with HSC beams, the cracks of UHPC beams are much more fully developed and densely distributed, with smaller widths. The increases in the volume of steel fibers and the stirrup ratio lead to the improvement in stiffness, deformation capacity and bearing capacity, and the reduction in stiffness degradation rate. The increase in the shear span ratio leads to improvement in the deformation capacity, but reduces the stiffness and bearing capacity. After the concrete cracks, the steel fibers can bridge the cracks and share the tensile force at the cracks with the stirrup, and thus delay the development of the strain in the stirrup. Based on the modified compression field theory, a calculation method for the shear capacity of UHPC beams was proposed, and the corresponding results were compared with those from the methods recommended by AFGC-Setra 2013 and KCI-2012. The proposed method can accurately predict the shear bearing capacity of UHPC beams.

关 键 词：配筋超高性能混凝土梁 钢纤维 受剪性能 受剪承载力 修正压力场理论 

分 类 号：TU377[建筑科学—结构工程] TU317.1