双侧压下混凝土静态受拉与受拉疲劳性能研究

STATIC AND FATIGUE TENSILE BEHAVIOR OF CONCRETE UNDER BILATERAL COMPRESSION

  • 摘要: 进行了双向侧压作用下混凝土静态受拉与受拉疲劳试验.对静态受拉试验的极限抗拉强度、轴向拉伸应变和侧向压缩应变进行了比较分析,轴向拉伸应变因侧压的存在而快速增长,侧向压缩应变也因轴拉作用而增大,而极限抗拉强度则因侧压影响而降低;对受拉疲劳试验,则得到了S-N方程,应力应变曲线,应变、疲劳变形模量比与疲劳次数关系曲线,其特征表现为三阶段规律;并通过定义的对数线性变换把上述三阶段曲线转换为直线;反之,利用这种线性关系可以求得三阶段曲线关系.同时对静态受拉与受拉疲劳试验的相关物理量进行了比较分析,疲劳寿命和疲劳变形模量也因侧压的影响而有较大幅度的降低.

     

    Abstract: The static and fatigue tensile behavior of concrete under bilateral compression is studied experimentally. The ultimate tensile strength, axial tensile strain and lateral compression strain are obtained and compared. It is seen that the axial tensile strain develops rapidly and the ultimate tensile strength decreases greatly with lateral compression. On the other hand, lateral compression strain develops rapidly with axial tension too. Through tensile fatigue experiments, some S-N equations, curves of stress-strain, strain-ratios of deformation modulus and strain-number of cycles relationships which comply with the three-stage rules are obtained. Three-stage curves are transformed to lines by defining logarithmic linear transformation variables εt and etm, respectively. Contrariwise, the three-stage curves can be established by the linear relationships. The comparative analyses of correlative physical parameters of concrete in static tension and tensile fatigue show that fatigue life and deformation modulus reduce largely because of lateral compression.

     

/

返回文章
返回