Fibers crossing sliding crack planes have a positive influence on capacity because they can transfer shear load as dowels. Such behavior was evidenced by several researches that investigated the direct shear performance of Fiber-Reinforced Concrete. However, there is limited literature on the direct shear pullout behavior of single fibers, which certainly provides a deeper understanding of the mechanisms involved in direct shear. Therefore, this paper presents a new approach to perform direct shear pullout (or dowel pullout) of single fibers with a developed portable test apparatus, which enables performing the typical pullout with aligned fiber and load as well. From the comparison between the dowel and aligned pullouts, the energy dissipation capacity and the bond strength of the samples tested under direct shear were found 3.13 and 1.77 times greater than the aligned ones, respectively. The remarkable differences are attributed to the increase in fiber/matrix friction due to the shear load and the continuous occurrence of plastic strains, evidenced by the fiber shape at the end of the dowel pullout. Both mechanisms can be associated with the snubbing effect. Furthermore, the test methodology presented small coefficients of variation (CV) for pullout work and bond strength. For the direct shear pullout, the CVs were 9.57% and 10.42%, respectively, and for the aligned pullout were 16.73% and 18.95%, respectively.

穿过滑动裂纹平面的纤维对承载力有积极影响，因为它们可以像销钉一样传递剪切载荷。通过研究纤维增强混凝土的直接剪切性能的几项研究证明了这种行为。然而，关于单纤维的直接剪切拔出行为的文献有限，这无疑提供了对直接剪切所涉及的机理的更深入的了解。因此，本文提出了一种新的方法，可以通过开发的便携式测试设备对单根纤维进行直接剪切拔出（或销钉拔出），该方法还可以在对准光纤和负载的情况下执行典型的拔出操作。从定位销和对齐的抽出物之间进行比较，发现直接剪切下测试的样品的能量耗散能力和粘结强度分别为3.13和1。比对齐的分别大77倍。显着的差异归因于由于剪切载荷和连续出现塑性应变而导致的纤维/基体摩擦力的增加，这在销钉拔出末端的纤维形状得到了证明。两种机制都可能与缓冲效应相关。此外，该测试方法为拔出功和粘结强度提供了较小的变异系数（CV）。对于直接剪切拉样，CV分别为9.57％和10.42％，对于对齐拉样，CV分别为16.73％和18.95％。两种机制都可能与缓冲效应相关。此外，该测试方法为拔出功和粘结强度提供了较小的变异系数（CV）。对于直接剪切拉样，CV分别为9.57％和10.42％，对于对齐拉样，CV分别为16.73％和18.95％。两种机制都可能与缓冲效应相关。此外，该测试方法为拔出功和粘结强度提供了较小的变异系数（CV）。对于直接剪切拉样，CV分别为9.57％和10.42％，对于对齐拉样，CV分别为16.73％和18.95％。