摘要
利用分离式霍普金森压杆(SHPB)试验装置,对不同碳纳米管体积掺量(0.1%、0.2%、0.3%、0.4%、0.5%)的碳纳米管增强混凝土进行了平台巴西圆盘动态劈裂拉伸试验,通过分析碳纳米管掺量和冲击速率对混凝土破坏形态、强度、耗散能等行为特征的影响,研究了冲击荷载下碳纳米管增强混凝土的劈裂拉伸性能,并分析了碳纳米管的强韧化效应。结果表明:随着冲击速率的增大,混凝土的破坏程度等级不断增大。混凝土的动态劈裂拉伸强度、动态劈裂拉伸强度增长因子(DIF)和耗散能均具有冲击速率强化效应。碳纳米管可以提高混凝土的抗冲击破坏能力和动态劈裂拉伸性能,可以增强混凝土动态劈裂拉伸强度和耗散能的冲击速率强化效应。随着碳纳米管掺量的增大,混凝土的动态劈裂拉伸强度、DIF和耗散能均先增大后减小,混凝土动态劈裂拉伸强度和耗散能的冲击速率强化效应均先增强后减弱。碳纳米管的最佳掺量为0.3%。碳纳米管对混凝土动态劈裂拉伸强度和耗散能的最大增幅分别为49.76%、212.45%。
Dynamic splitting tensile behavior of carbon nanotube-reinforced concrete was investigated using a split Hopkinson pressure bar(SHPB)system with Brazilian disc specimens at varying carbon nanotube volume content(0.1%,0.2%,0.3%,0.4%,0.5%).By analyzing the effects of carbon nanotube content and impact rate on the failure morphology,strength,and dissipated energy of concrete,the splitting tensile properties of carbon nanotube-reinforced concrete under impact loading were studied,and the toughening effect of carbon nanotubes was analyzed.The experimental results demonstrate that concrete damage severity exhibits a positive correlation with dynamic splitting tensile strain rate.Both dynamic splitting tensile strength and its corresponding dynamic increase factor(DIF),along with energy dissipation capacity,display significant strain-rate dependency,revealing pronounced rate-strengthening effects.The dynamic splitting tensile strength,DIF,and dissipated energy of concrete exhibit a non-monotonic relationship with carbon nanotube content,initially increasing before reaching an optimal threshold and subsequently decreasing.Similarly,the strain-rate strengthening effects on both dynamic splitting tensile strength and energy dissipation capacity exhibit a comparable trend:an initial enhancement followed by attenuation with increasing carbon nanotube concentration.The optimal carbon nanotube content is determined to be 0.3%,demonstrating maximum enhancements of 49.76% in dynamic splitting tensile strength and 212.45% in energy dissipation capacity.
作者
李智峰
陆凤鸣
LI Zhi-feng;LU Feng-ming(Shanxi Vocational University of Engineering Science and Technology,Jinzhong 030619,China;College of Architecture,Taiyuan University of Technology,Taiyuan 030000,China)
出处
《爆破》
北大核心
2026年第1期20-28,48,共10页
Blasting
基金
山西省高等学校科技创新项目(2024L418)。
关键词
混凝土
碳纳米管
冲击速率
动态劈裂拉伸性能
强度
concrete
carbon nanotube
impact rate
dynamic splitting tensile property
strength
