考虑到地震作用下大体积碾压混凝土结构响应的特点,对两种级配的碾压混凝土进行了单向应力状态下的动态拉、压试验,系统研究了应变速率对碾压混凝土单轴强度及变形特性的影响,分析了在不同应变速率下强度、峰值应变、极限应变以及弹性模量等特性的变化规律及其发生机理。结合碾压混凝土动态强度增量、弹性模量、峰值应变等与应变率之间的拟合公式,给出了描述碾压混凝土在不同应变速率下应力-应变全曲线的表达式,并对碾压混凝土的动态破坏过程进行了探讨,为开展碾压混凝土高坝的动力反应分析打下了基础。
With consideration of the stress state of large-scale roller compacted concrete(RCC) structures exposed to earthquakes,the uniaxial properties of RCC with two different grading types of aggregate under both tensile and compressive dynamic loadings were experimentally tested.The rate-dependent deformation behaviors were studied,and the strength,elastic modulus and critical strain were tested over a rather wide range of strain rate.Static and dynamic constitutive models were analyzed and compared using the relationships between the strain rate and the elastic modulus,critical strain and dynamic strength increment of RCC,and formulas were proposed to describe the complete stress-strain curves at varying strain rates.The fracturing process of RCC under dynamic loadings was also studied.The present work would provide a basis for dynamic behavior study of high RCC arch dams.