钢纤维再生混凝土抗冲击性能研究

Study on impact behavior of steel fiber recycled concrete

参照ACI544委员会落锤冲击试验方法,采用自制落锤冲击试验装置对钢纤维再生混凝土试件的抗冲击性能进行了试验研究,考虑了不同的钢纤维体积掺量(0、0.5%、1.0%、1.5%)、不同的钢纤维类型(端钩型和波纹型)及不同的再生粗骨料取代率(0、50%、100%)等因素对钢纤维再生混凝土的抗冲击性能的影响,并同时对各试件的抗压强度进行了分析。结果表明:加入一定掺量的钢纤维之后,再生混凝土的抗冲击性能明显提高、延性性能显著改善,且端钩型钢纤维比波纹型对再生混凝土抗冲击的改善效果更好。另外发现,随着再生骨料取代率的增加,钢纤维再生混凝土的抗压强度与抗冲击性能均有所下降。最后在试验基础上采用大型通用有限元分析软件ANSYS/LS-DYNA建立了落锤冲击作用下钢纤维再生混凝土试件的三维有限元数值分析模型,数值模拟结果与试验吻合较好。

According to the drop-weight test method of ACI Committee 544,the impact resistance of steel fiber recycled concrete specimens was studied by using a self-made drop-weight test device.Considering the influence of different factors on the impact resistance of steel fiber recycled concrete,including different steel fiber volume content(0,0.5%,1.0%and 1.5%),different steel fiber types(hook type and corrugated type)and different replacement rates of recycled coarse aggregate(0,50%and 100%).The compressive strength of each specimen was also analyzed.The results show that the addition of steel fiber could significantly increase the impact resistance and ductility of recycled aggregate concrete.The steel fiber reinforced recycled aggregate concrete with end hook steel fiber has higher impact resistance than that with corrugated steel fiber.In addition,it was found that the compressive strength and impact resistance of recycled aggregate concrete decreased with the increase of the replacement rate of recycled aggregate.Finally,based on the experiment,a large-scale general finite element analysis software ANSYS/LS-DYNA was used to establish a three-dimensional finite element numerical analysis model of steel fiber recycled concrete specimens with drop hammer impact.The numerical simulation results agree well with the test.