This paper presents a hybrid-fibre-reinforced concrete containing different amounts of steel fibres, nanosilica and multi-wall carbon nanotubes. A combination of fibres in different sizes was considered for bridging and closure of cracks in different stages of the crack growth and improving post-fracture behaviour. Moreover, pozzolanic materials such as nanosilica with high surface energy were employed for increasing the strength of the transition zone. First, investigations were carried out to achieve an optimum mix design and evaluate strength properties and energy absorption capability. Second, impact tests with two types of projectiles were conducted on slab specimens of different sizes and types. In conclusion, the addition of nanoparticles and combination of fibres led to a significant increase in toughness and impact strength.

中文翻译：

---

包含多壁碳纳米管的混合纤维增强混凝土

本文提出了一种混合纤维增强混凝土，其中包含不同数量的钢纤维，纳米二氧化硅和多壁碳纳米管。考虑了不同尺寸的纤维的组合，以便在裂纹扩展的不同阶段桥接和封闭裂纹，并改善断裂后的行为。此外，采用火山灰材料如具有高表面能的纳米二氧化硅来增加过渡区的强度。首先，进行了研究以实现最佳的混合料设计并评估强度性能和能量吸收能力。其次，在不同大小和类型的平板样本上进行了两种弹丸的冲击试验。总之，纳米颗粒的添加和纤维的结合导致韧性和冲击强度的显着提高。