摘要
为探究氧化铝纤维改性混凝土在冲击荷载作用下的动态拉伸性能,利用分离式霍普金森压杆(SHPB)试验装置,对不同纤维掺量(体积分数分别为0.1%、0.2%、0.3%、0.4%和0.5%)的氧化铝纤维改性混凝土进行了动态平台巴西圆盘劈裂拉伸试验,分析了氧化铝纤维掺量和子弹冲击速度(即加载速率)对混凝土动态劈拉应力-时程曲线、动态劈拉强度等力学参数的影响规律。结果表明:混凝土的动态劈拉应力-时程曲线与加载速率和氧化铝纤维掺量密切相关,加载速率越大,曲线到达峰值点所需的时间越短,掺入氧化铝纤维之后,曲线的峰后阶段震荡下降,具有一定的硬化特征。随着加载速率的增加,氧化铝纤维改性混凝土的动态劈拉强度呈近似线性增大的变化趋势,表现出明显的冲击强化效应。掺加适量的氧化铝纤维能够改善混凝土的动态劈拉特性,基于本文试验条件,氧化铝纤维的相对最佳体积掺量为0.2%。
In order to investigate the dynamic tensile performance of alumina fiber reinforced concrete under impact loading,a series of dynamic Brazilian disc splitting tests were conducted using a split Hopkinson pressure bar(SHPB)apparatus.Different fiber volume fractions(0.1%,0.2%,0.3%,0.4%and 0.5%)of alumina fiber were incorporated into the concrete mix.The effects of alumina fiber content and bullet impact velocity(i.e.,loading rate)on the dynamic splitting tensile stress-time curves and dynamic splitting tensile strength of the concrete were analyzed.The results showed that the dynamic splitting tensile stress-time curves of the concrete were closely related to both the loading rate and alumina fiber content.As the loading rate increased,the time taken to reach the peak point of the curve decreased.After the inclusion of alumina fibers,the post-peak stage of the curve demonstrated oscillatory decline,indicative of certain hardening characteristics.With the increase in loading rate,the dynamic splitting tensile strength of alumina fiber reinforced concrete exhibited an approximately linear increasing trend,reflecting a significant impact enhancement effect.The addition of an appropriate amount of alumina fibers can improve the dynamic splitting tensile characteristics of concrete.Based on the experimental conditions of this study,the optimal relative volume fraction of alumina fibers was found to be 0.2%.
作者
夏伟
白二雷
许金余
秦立军
姚廒
XIA Wei;BAI Erlei;XU Jinyu;QIN Lijun;YAO Ao(Air Force Engineering University;Northwestern Polytechnical University;Unit 95926 of PLA)
出处
《防护工程》
2025年第1期1-7,共7页
Protective Engineering
基金
国家自然科学基金面上项目(52278287)
