超高性能混凝土的抗剪强度  

Shear Strength of Ultra-High Performance Concrete

作　　者：王晓飞[1] 周海龙[1] 王海龙[1] WANG Xiaofei;ZHOU Hailong;WHANG Hailong(College of Water Conservancy and Civil Engineering,Inner Mongolia Agricultural University,Hohhot 010018,China)

机构地区：[1]内蒙古农业大学水利与土木建筑工程学院,呼和浩特010018

出　　处：《硅酸盐学报》2022年第8期2190-2195,共6页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金(52069024);内蒙古自然科学基金资(2020MS5076)。

摘　　要：抗剪切强度指标值(黏聚力和内摩擦角)是超高性能混凝土本构关系研究和数值模拟分析的重要数据,对揭示超高性能混凝土中钢纤维的增强增韧机理至关重要。通过对4种钢纤维体积含量(0%、1%、2%和3%)的超高性能混凝土在5档围压(0、10、20、40 MPa和60 MPa)下进行常规三轴压缩试验,得到各应力路径下超高性能混凝土的轴向、径向应力应变全曲线及应力圆。应力应变全曲线图显示,围压为40MPa时,4种钢纤维超高性能混凝土在三轴压缩试验中均表现出一定的流变性质,超高性能混凝土变形性质及破坏模式由脆性开始向塑性转变。并由应力圆数据推导出每种钢纤维含量超高性能混凝土在不同围压下内摩擦角φ和黏聚力c的具体数值,并给出了内摩擦角φ和黏聚力c随钢纤维体积含量和围压增大的变化规律。结果显示:钢纤维含量相同,黏聚力随围压的增大而增大,内摩擦角随围压的增大而减小;同围压下钢纤维体积含量为2%时黏聚力最大,内摩擦角最小,有围压时钢纤维含量对内摩擦角的影响较小。The shear strength index values(cohesion and internal friction angle)are important data for the study of constitutive relationships and numerical simulation analysis of ultra-high performance concrete,which are crucial to revealing the reinforcement and toughening mechanism of steel fibers in ultra-high-performance concrete.The axial direction and radial direction stress-strain full curves data and stress circles of ultra-high performance concrete under each stress path were obtained via conventional triaxial compression experiment of ultra-high performance concrete with different steel fiber volume contents(i.e.,0%,1%,2%and 3%)at different confining pressures(i.e.,0,10,20,40 MPa and 60 MPa).Based on the stress-strain full curve,the ultra-high performance concretes with different steel fiber contents have some rheumatic properties in the triaxial compression process,and the deformation properties and destruction modes change from brittleness to plasticity at a confining pressure of 40 MPa.The specific values of internal friction angle(φ)and adhesion(c)at different confining pressures of each steel fiber content ultra-high performance concrete were deduced from the stress circle data,and the changes ofφand c with the increase of steel fiber content and confining pressure were also analyzed.The results show that the cohesion increases with the increase of confining pressure,and the internal friction angle decreases with the increase of confining pressure at the same steel fiber content.The maximum cohesion and the minimum internal friction angle are achieved at the same confining pressure and a steel fiber volume content of 2%.The content of steel fiber has little effect on the internal friction angle at a certain confining pressure.

关 键 词：超高性能混凝土 钢纤维 内摩擦角 黏聚力 应力圆 

分 类 号：TU528.572[建筑科学—建筑技术科学]