钢纤维取向及其对超高性能混凝土力学性能影响研究综述

Steel Fiber Alignment and Its Effect on the Mechanical Properties ofUltra-high Performance Concrete:a Review

超高性能混凝土(Ultra-high performance concrete,UHPC)以其优异的力学性能和耐久性在工程中得到了广泛的应用。钢纤维是UHPC中重要的添加材料,确保与主拉应力方向相对应的纤维取向可以大大提高UHPC的力学性能,特别是抗弯性能和拉伸性能。本文综述了钢纤维定向方法及其对UHPC力学性能的影响。在浇注过程中,磁场诱导方式具有更好的改善效果,最大提升幅度可达80%。钢纤维进行定向处理之后,静态抗弯强度、韧性和抗拉强度分别比随机纤维取向提高10%~80%、20%~100%和30%~90%。提出了超高性能混凝土中钢纤维取向分布研究中存在的问题和研究思路,最后展望了电磁诱导钢纤维定向技术在大体积超高性能混凝土浇筑中的应用前景。

Ultra-high performance concrete(UHPC)has been widely used in engineering due to its excellent mechanical properties and durability.Fiber is an important additive material in UHPC.Securing fiberalignment corresponding to the direction of principal tensile stress can greatly improve the mechanical properties of UHPC,especially the flexural and tensile properties.In this paper,an overview on fiber alignment and its effect on mechanical properties of UHPC is presented.The assistance of electromagnetic field during casting can lead to a higher improvement in fiber orientation(up to 80%)compared to other fiber alignment methods.Flexural strength,toughness,and tensile strength can be enhanced by 10%—80%,20%—100%,and 30%—90%,respectively,for UHPC with fiber alignment compared to those with random fiber orientation.In addition,the problems and possible future research direction in the study of steel fiber alignment in ultra-high performance concrete are put forward.Finally,the application prospect of electromagnetic induced steel fiber alignment technology in the casting of large volume ultra-high performance concrete is prospected.