This paper summarizes the results obtained in an experimental campaign on the effect of the displacement pullout rate and the inclination angle of the steel fiber pullout tests. For that purpose, specimens were obtained from a self-compacting concrete with a compressive strength of 86 MPa. In the experimental program, hooked-end steel fibers of 0.75 mm diameter and 60 mm length were used. Tests were executed with both hooked-end fibers, and smooth fibers obtained from the former by cutting the hooked end. For both type of fibers, their embedment length into concrete was 20 mm, and the influence of fiber inclination angle toward the load direction was investigated by adopting values of $$0^{\circ }$$ 0 ∘ , $$30^{\circ }$$ 30 ∘ and $$60^{\circ }$$ 60 ∘ . The tests were performed at displacement rates of 0.01, 0.1 and 1 mm/s. The results have shown that the peak pullout load increased with the inclination angle, in particular for the smooth series. Furthermore, higher displacement rates led to a higher energy absorption capacity for the pullout of the smooth fibers, while the energy absorption remained almost stable for hooked-end fibers.

中文翻译：

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钢纤维拉拔试验中位移率和倾角的影响

本文总结了在位移拉拔率和钢纤维拉拔试验倾角影响的实验活动中获得的结果。为此，从抗压强度为 86 MPa 的自密实混凝土中获得了试样。在实验程序中，使用了直径为 0.75 毫米、长度为 60 毫米的钩端钢纤维。对钩端纤维和通过切割钩端从前者获得的光滑纤维进行测试。对于这两种类型的纤维，它们在混凝土中的嵌入长度均为 20 mm，采用 $$0^{\circ }$$ 0 ∘ , $$30^{\circ }$$ 30 ∘ 和 $$60^{\circ }$$ 60 ∘ 。测试以 0.01、0.1 和 1 mm/s 的位移速率进行。结果表明，峰值拉拔载荷随着倾斜角的增加而增加，特别是对于平滑系列。此外，较高的位移率导致拉出光滑纤维的能量吸收能力较高，而钩端纤维的能量吸收几乎保持稳定。