【摘要】 采用常三轴动力试验仪对不同钢纤维含量、不同围压、应变速率为10-3/s作用下混凝土的主要参数进行试验与分析,结果表明:①随着围压的增大,各种不同钢纤维含量的混凝土峰值应力显著提高;②同一种围压条件下,基体强度等级愈高峰值应力的增加幅度也愈高,峰值应力随钢纤维含量的变化不大;③围压对峰值应变的影响较大,随围压的增大,峰值应变明显增大;在有围压的条件下峰值应变随钢纤维含量的增加而提高得不多;④钢纤维含量对割线模量有一定的影响,对基体强度较低的混凝土的影响要比强度等级高的混凝土显著;围压对钢纤维混凝土割线模量也有一定影响,随围压的增加,钢纤维混凝土的割线模量表现为先增加后减小,但增加和减小的程度都不大;围压的变化对基体强度较高的混凝土割线模量影响不大,对基体强度较低的混凝土基本呈下降趋势;⑤混凝土的泊松比离散性较大,钢纤维含量和围压对泊松比的影响不是很大,主要集中在0.11～0.20之间;⑥在三轴动荷载的情况下,钢纤维的掺入对混凝土的压缩韧度指数ηc5基本上没有影响;但韧度指数ηc10随钢纤维含量的增加有显著提高,变形不大时作用不明显,当变形较大时,钢纤维提高韧性的作用得以充分体现;钢纤维的增韧效果在基体强度较低的混凝土中表现得较为显著。更多还原

【Abstract】 Tests of concrete with different steel fiber contents,confining pressures and loading rates are conducted using conventional three-axial dynamic apparatus. The results are as follows:①With the increase of confining pressure,the peak stress of concrete with various steel fiber contents increases significantly. ②Under identical confining pressure,the higher the strength grade of the concrete,the higher the growth rate of the peak stress is,while the fiber content of concrete impacts little on the peak stress. ③Concrete peak strain is more sensitive to the confining pressure,while less sensitive to the steel fiber content. ④Steel fiber content affects the secant modulus,especially for low-strength grade concrete,and the confining pressure also affects the secant modulus,but the range of variation range is rather small. ⑤The values of Poissons ratio of concrete is scattered,varying between 0.11 and 0.20,and steel fiber content and confining pressure does not impact much on Poisson’s ratio. ⑥Under three-axial dynamic load,fiber content of concrete does not impact much on the index toughness in compression,ηc5. Toughness index,ηc10,increases significantly with the increase of steel fiber content,when the deformation is larger,especially for low-strength concrete.更多还原