Quantifying the recycled nylon fibers influence on geometry of crack and seepage behavior of cracked concrete. (10th April 2023)

• Record Type: Journal Article
• Authors: Li, Ming; Chai, Junrui; Zhang, Xianwei; Qin, Yuan; Ma, Weili; Duan, Minghan; Zhou, Heng
• Is Part Of: Construction & building materials. Volume 373(2023)
• Publication Date: 2023-04-10
• Subjects: Recycled nylon fibers -- Fiber reinforced concrete -- Crack geometry -- Numerical simulation -- Non-linear flow -- Permeability; Building materials -- Periodicals; 624.18
• DOI: 10.1016/j.conbuildmat.2023.130853
• Languages: English
• ISSNs: 0950-0618

Abstract

Highlights: The effect of using waste nylon fibers on the permeability of concrete is investigated. The numerical simulation model of the seepage flow in a single crack of concrete is established. The effect of fibers on the internal geometric properties of concrete cracks is analyzed. Abstract: The durability of concrete is closely related to the permeability of material and the fibers are commonly used for concrete reinforcement. In recent years, the environmental impact of synthetic fibers has resulted in growing concerns, the fibers from the recycled materials show great potential applications in engineering. This paper aims to investigate the influence of using waste nylon fiber fabric (NFF) recycled from cloths, instead of nylon fiber (NF), on the seepage within cracked concrete. The evolution of seepage flow behavior in and permeability of cracked fiber reinforced concrete (FRC) under different water pressure is discussed, and the effect of fibers on crack geometric parameters is analyzed. Cracked specimens are obtained by the feedback controlled splitting test, and a self-developed device is adopted for the variable water pressure permeability test. The basic data of the crack surface is collected using a handheld 3D scanner and the numerical simulation model is established to analyze the evolution of flow rate in the crack under different boundary conditions. Results show that the experimental data on water pressure gradient as a function of the volumetric flow rate shows obvious non-linear trend and fits well with Forchheimer' s law. The flow rate is non-uniformly distributed in the crack and appears as the normal distribution. The water permeability decreases as the geometry of the crack surface becomes more roughness with the increase of the fiber dosage. The modified cubic law based on the geometric parameters of the crack surface can be adopted to predict the crack permeability well, and the correction factors ξ of NFRC and NFFRC is between 0.028 and 0.080.