This paper investigates and compares the effect of steel fibres obtained through recycling waste tyres (known as RTSF), and a commercially available hooked steel fibre (HSF), on plastic shrinkage cracking in self-compacting concrete. The volumetric deformations of the specimens, bleeding, and the mass loss have been quantified. Mixtures containing 2.5, 5, 7.5 and 10 kg/m³ of RTSF, and 5 and 7.5 kg/m³ of HSF have been tested. The results show that an almost similar reduction of the crack area can be attained if HSF is replaced by a slightly higher amount of RTSF. However, the former seems to be more effective in restraining plastic shrinkage. Both fibres decreased the volumetric shrinkage and the bleeding capacity of the specimens.

中文翻译：

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再生轮胎提取钢纤维对自密实混凝土塑性收缩开裂的影响

本文研究并比较了通过回收废轮胎获得的钢纤维（称为 RTSF）和市售的钩状钢纤维（HSF）对自密实混凝土中塑性收缩开裂的影响。样品的体积变形、渗出和质量损失已被量化。已经测试了包含 2.5、5、7.5和 10 kg/m ³的 RTSF 以及 5 和 7.5 kg/m ³的 HSF 的混合物。结果表明，如果用稍高量的 RTSF 代替 HSF，可以实现几乎相似的裂纹面积减少。然而，前者在抑制塑性收缩方面似乎更有效。两种纤维都降低了样品的体积收缩率和泌水能力。