【摘要】 对钢纤维含量分别为0%、1%、2%、4%、6%的C30和C40混凝土进行了常三轴动态压缩试验,C30混凝土试件围压值为0MPa、6MPa、9MPa、12MPa、18MPa、24MPa,C40混凝土试件围压值为0MPa、8MPa、12MPa、16MPa、24MPa、32MPa;试验过程中采用位移控制模式下的正弦波分级加载。在此基础上,进行了应力-应变全曲线表达式的选择与分析,并对各材料参数与诸因素间的相关性进行了分析。结果表明:1)通过对Ezeldin等提出的钢纤维混凝土静态荷载作用下的应力-应变全曲线公式进行β参数修正,使得该模型可以很好地描述钢纤维混凝土在动态常三轴压缩作用下的应力-应变全曲线关系;2)纤维含量对C40混凝土的动态抗压强度的改善作用比对C30混凝土显著,但受压状态下纤维含量对提高混凝土动态强度总的幅度较小;3)混凝土动态峰值应力对围压大小较敏感,C40混凝土的敏感性对C30混凝土有所下降,峰值应变与诸因素的相关关系基本上与峰值应力相同;4)在动态荷载作用下钢纤维混凝土的割线弹性模量、钢纤维含量与割线模量间的相关性,均表现为C40混凝土比C30混凝土要高;5)围压与纤维含量对混凝土材料的受压状态下的韧度指数ncmax不产生太大影响。更多还原

【Abstract】 The steel fiber content of 0%, 1%, 2%, 4%, 6% of the C30 and C40 concrete were conducted on the conventional three-axis experiment for a regular three-axis dynamic compression test. The confining pressure values of 0, 6, 9, 12, 18 and 24 MPa were used on the C30 concrete specimens, the confining pressure values of 0, 8, 12, 16, 24 and 32 MPa were used on the C40 concrete specimens; The concrete specimen is loaded in certain sine-wave pressures in axis grade by grade. On this basis, the expression of the stress-strain curve was chosen and analyzed, the correlation of the material parameters and the factors were analyzed. The results show that: 1) the stress-strain curve formula parameters using for the SFRC under static force presented by Ezeldin are modified,the modified model has a good description of the stress-strain curve of the SFRC under the three-axis dynamic compression; 2) fiber content on dynamic role of improving the compressive strength of the C40 concrete show more significant than that of C30 concrete, but the improvement of the fiber content to the dynamic strength of the concrete is not considerable under pressure; 3) the concrete dynamic peak stress shows more sensitive on confining pressure size; comparing with C30, the sensitivity of C40 is slighter; the peak strain relationship among other factors is basically the same as that of the peak stress; 4) under dynamic loading, the performance of C40 is higher than that of C30 on the secant elasticity modulus, the relationship between the secant modulus and the steel fiber content; 5) the confining pressure and fiber content of concrete have not much impact on the index toughness on the state of compression.更多还原