Zhao Xin, Cai Lei, Ji Xiaohua, Zeng Wei, Liu Jintao
School of Civil Engineering and Architecture, Zhejiang University of Science and Technology, Hangzhou 310023, China.
College of Civil Engineering and Architecture, Zhejiang University, Hangzhou 310058, China.
Materials (Basel). 2022 Dec 7;15(24):8734. doi: 10.3390/ma15248734.
Ultra-high performance concrete (UHPC) is a kind of cement-based material with ultra-high strength, high toughness and excellent durability. However, the tensile strain capacity of UHPC is often below 0.5%, and the mode of single crack failure is the main failure pattern, which limits the development of UHPC. In order to overcome the weakness of the relatively low strain capacity of UHPC, five types of polyethylene (PE) fibers with different geometrical and mechanical parameters (length, diameter and elastic modulus) were added into the matrix, and the corresponding mechanical behavior was investigated. The experimental results showed that the high fiber length and fiber diameter of PE fibers are a benefit for the compressive strength and tensile strength of UHPC. The increase of the fiber diameter and elastic modulus remarkably attributed to the increase in the tensile strain capacity of UHPC. With the increase of the fiber diameter and elastic modulus, the overall energy absorption capacity and the energy absorption capacity of the substrate prior to the softening section of UHPC were both enhanced. The diameter of PE fiber was the main factor affecting the energy consumption of UHPC. Among the five types of PE fiber, fiber ( fiber is PF type polyethylene fiber; Fiber length: 15 mm; Fiber diameter: 27 μm; Elastic Modulus: 117 GPa) is the optimal fiber to increase the tensile mechanical behavior of UHPC.
超高性能混凝土（UHPC）是一种具有超高强度、高韧性和优异耐久性的水泥基材料。然而，UHPC的拉伸应变能力通常低于0.5%，单裂缝破坏模式是主要的破坏形式，这限制了UHPC的发展。为了克服UHPC应变能力相对较低的弱点，将五种具有不同几何和力学参数（长度、直径和弹性模量）的聚乙烯（PE）纤维加入到基体中，并研究了相应的力学行为。实验结果表明，PE纤维的高纤维长度和纤维直径有利于UHPC的抗压强度和抗拉强度。纤维直径和弹性模量的增加显著归因于UHPC拉伸应变能力的提高。随着纤维直径和弹性模量的增加，UHPC的整体能量吸收能力以及软化段之前基体的能量吸收能力均得到增强。PE纤维直径是影响UHPC能量消耗的主要因素。在这五种PE纤维中，纤维（纤维为PF型聚乙烯纤维；纤维长度：15mm；纤维直径：27μm；弹性模量：117GPa）是提高UHPC拉伸力学性能的最佳纤维。
