约束应力下UHPC直剪性能试验及有限元验证  

Experimental Investigation and Finite Element Verification of the Direct Shear Performance of UHPC under the Confining Stress

作　　者：秦磊 周宇 

机构地区：[1]长沙理工大学,湖南长沙410004 [2]云南省交通运输厅,云南昆明650032

出　　处：《混凝土世界》2023年第5期39-45,共7页China Concrete

基　　金：湖南省研究生实践创新项目(2022ZDK002)。

摘　　要：通过使用3个“Z”型推出试件和有限元模拟来研究超高性能混凝土(UHPC)的直接剪切行为。使用约束应力作为测试变量,对剪切行为的荷载-相对滑移曲线、初裂强度、直接剪切强度、破坏模式等进行了试验和有限元模拟验证。试验结果表明:约束应力为0、4、7MPa的UHPC,其直剪强度分别为19.17、25.21、28.46MPa。用模拟对比试验的极限剪切强度,两者比值的平均值为0.981,标准差为0.018,模拟结果非常吻合。由于约束应力的作用,UHPC的剪切刚度、剪切滑移量及残余承载能力会相应增大,但约束应力的增大对残余承载能力的提升并不明显,这与失效时释放的能量有关。In this investigation,the direct shear behavior of UHPC was studied by using three Z-shaped specimens and finite element simulations with the confining stresses as test variables.The load-relative slip curve,initial crack strength,direct shear strength,and damage mode of the shear behavior were verified by tests and finite element simulations.The test results showed that the direct shear strengths of UHPC with confining stresses of 0,4,and 7 MPa were 19.17,25.21,and 28.46 MPa,respectively.Comparing the test results with the simulation results,the mean value of the two ratios was 0.981 and the standard deviation was 0.018,and the simulation results were in good agreement.The shear stiffness,shear slip and residual load capacity of UHPC will increase accordingly due to the confining stress.However,the increase in confining stress has no significant increase in residual load capacity,which is related to the energy released during failure.

关 键 词：超高性能混凝土 侧向约束应力 直接剪切性能 有限元模拟 

分 类 号：TU528[建筑科学—建筑技术科学]