聚丙烯纤维对RPC动态劈裂性能的影响

Effect of polypropylene fiber on dynamic splitting of RPC

为研究聚丙烯纤维(PF)掺量对活性粉末混凝土(RPC)动态劈裂抗拉性能的改善效果,利用φ74 mm分离式霍普金森压杆(SHPB)加载系统开展不同掺量(0、0.05%、0.1%和0.15%)的动态冲击试验,探讨PF掺量和冲击荷载下的RPC动态力学特性与能量耗散变化规律。结果表明:在一定掺量范围下,PF的掺入可增强RPC的动态劈裂抗拉强度,掺量为0.05%时抗拉强度最高,试件动态峰值拉应力随PF掺量的增加呈先增大后减小的趋势,二者满足二次函数关系;同时,PF的掺入降低了试件的破坏程度,产生较好的阻裂效果;RPC试件的耗散能占比与耗散能密度受到PF掺量的影响。

To explore the improvement effect of polypropylene fiber(PF)content on the dynamic splitting tensile properties of reactive powder concrete(RPC),the dynamic impact tests with different contents(0,0.05%,0.1% and 0.15%)were carried out by using the split Hopkinson pressure bar(SHPB)loading system of φ74 mm.The effects of PF content and impact load on dynamic characteristics and energy dissipation changes of RPC were analyzed.The results show that the PF improves the dynamic splitting tensile properties of RPC,the highest intensity was found at a PF content of 0.05%.As the content of PF was increased,the dynamic peaktensile stress of the specimen increases at first and then decreases,and the two satisfy quadratic function relationship.In addition,the PF reduces the damage degree of the specimen and produces a better crack resistance effect.The energy dissipation ratio and energy dissipation density of RPC specimens are affected by the PF content.