聚合物改性碳纤维增强混凝土的动态压缩力学性能

为探究聚合物改性碳纤维增强混凝土(PMCFRC)的动态压缩力学性能，利用直径Φ100 mm分离式霍普金森压杆(SHPB)试验装置，分别对碳纤维增强混凝土及聚合物体积分数为4vol%、8vol%、12vol%的PMCFRC进行了5组不同气压下的冲击压缩试验，获得了混凝土在不同应变率下的动态应力-应变曲线和破坏形态，分析了应变率和聚合物掺量对PMCFRC动态压缩强度、变形和韧性的影响规律。结果表明：PMCFRC的动态压缩强度、变形和韧性均具有明显的应变率强化效应，聚合物对PMCFRC的动态压缩力学性能既有强化效应，也有劣化效应。随着应变率的增大，PMCFRC的动态抗压强度、动态强度增长因子(DIF)、动态峰值应变、冲击韧性均逐渐增大。随着聚合物掺量的增大，PMCFRC的动态抗压强度、DIF、冲击韧性均先增大后减小，动态峰值应变不断增大。相同应变率水平下，4%PMCFRC的动态抗压强度、冲击韧性最大，破损程度最轻；8%PMCFRC的应变率敏感性最佳，DIF最大时达到1.94，对混凝土强度的增幅最大。聚合物一方面在混凝土基体中发挥着填充、阻裂、增韧作用，另一方面改善碳纤维-混凝土基体界面的粘结...

Dynamic compression mechanical properties of polymer modified carbon fiber reinforced concrete

To explore the dynamic compression mechanical properties of polymer modified carbon fiber reinforced concrete (PMCFRC), the diameter Φ100 mm split Hopkinson pressure bar (SHPB) test device was used to carry out impact compression tests under five sets of different air pressures on carbon fiber reinforced concrete and PMCFRC with polymer content of 4vol%, 8vol%, and 12vol% respectively. The dynamic stress-strain curve and failure morphology of concrete under different strain rates were obtained, and the influence of strain rate and polymer content on the dynamic compressive strength, deformation and toughness of PMCFRC was analyzed. The results show that the dynamic compression strength, deformation and toughness of PMCFRC have obvious strain rate strengthening effects, and the polymer has both strengthening and degrading effects on the dynamic compression mechanical properties of PMCFRC. As the strain rate increases, the dynamic compressive strength, dynamic strength increase factor (DIF), dynamic peak strain and impact toughness of PMCFRC gradually increase. With the increase of the polymer content, the dynamic compressive strength, DIF and impact toughness of PMCFRC first increase and then decrease, and the dynamic peak strain continues to increase. Under the same strain rate level, 4%PMCFRC has the largest dynamic compressive strength, impact toughness, and the least damage; 8%PMCFRC has the best strain rate sensitivity, the maximum DIF is 1.94, and the greatest increase in concrete strength. On the one hand, the polymer plays the role of filling, crack resistance and toughening in the concrete matrix, and on the other hand, it improves the bonding performance of the carbon fiber-concrete matrix interface; when the polymer content is large, it will form a “soft interlayer” in the concrete matrix.