Investigation of shear performance of UHPC by direct shear tests

• Published in: Engineering structures Vol. 183; pp. 780 - 790
• Main Authors: Wu, Pengtao, Wu, Chengqing, Liu, Zhongxian, Hao, Hong
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 15.03.2019; Elsevier BV
• Subjects: Concrete; Ductility; Empirical equations; Fiber volume fraction; Investigations; Mechanical properties; Push-off test; Shear strength; Shear tests; Slip; Steel; Steel fiber volume ratio; Steel fibers; Stirrup ratio; Ultra high performance concrete; Shear strength; Stirrup ratio; Ultra-high performance concrete; Steel fiber volume ratio; Push-off test
• ISSN: 0141-0296; 1873-7323
• DOI: 10.1016/j.engstruct.2019.01.055

•Push-off tests on Z-shaped specimens were conducted to study shear transfer behaviors of UHPC.•The influences of steel fiber volume ratio and stirrup ratio on the shear behavior of UHPC were investigated.•New empirical equations are derived for predicting the shear strength and load-slip characteristics of UHPC. Ultra-high performance concrete (UHPC) has been applied widely in modern structure construction. The outstanding mechanical properties of UHPC not only enable strong yet slim structural designs but also highlight its potential in protective structural constructions against extreme loads. In this study, the shear transfer behaviors of UHPC are investigated by push-off tests on Z-shaped specimens, investigating the influences of the microsteel fiber volume ratio and stirrup reinforcement ratio on the shear strength, shear slip, and shear crack width of UHPC. The test results indicate that using a microsteel fiber can enhance the shear strength of UHPC specimens. Within a reasonable range of the steel fiber volume ratio (optimum volume ratio ranges from 0% to 2.5% for microsteel fiber), the shear strength and shear slip of UHPC increase significantly, and the shear crack width reduces with an increasing steel fiber volume ratio. Additionally, the ductility, shear strength, and shear slip of UHPC increase significantly, and the shear crack width reduces with increasing stirrup ratio. Finally, the simplified empirical equations for the ultimate shear strengths of UHPC specimens are deduced, and indicate good agreement with the experimental results.