Effect of Fiber Orientation on the Fatigue Behavior of Steel Fiber‑Reinforced Concrete Specimens by Performing Wedge Splitting Tests and Computed Tomography Scanning

• Published in: International journal of concrete structures and materials 2024, 18(2), 77, pp.307-325
• Main Authors: Dorys C. Gonzalez, Alvaro Mena?Alonso, Jesus Minguez, Jose A. Martinez, Miguel A. Vicente
• Format: Article
• Language: English
• Subjects: Building Materials; Computed tomography; Concrete; Crack patterns; CT imaging; CT-scan technology; Cubes; Digital imaging; Engineering; Fatigue; Fatigue creep curve; Fatigue failure; Fatigue life; Fatigue testing machines; Fatigue tests; Fiber orientation; Fiber-reinforced concrete; Grooves; Image processing; Materials; Metal fatigue; Orientation effects; Prisms; Reinforced concrete; Reinforcing steels; Software; Solid Mechanics; Splitting; Steel fiber reinforced concretes; Steel fibers; Structural Materials; Tomography; Wedge splitting test; 토목공학
• ISSN: 1976-0485; 2234-1315; 2234-1315
• DOI: 10.1186/s40069-023-00639-8

This paper shows the relationship, in steel fiber-reinforced concrete, between fiber orientation and fatigue response through the combined use of computed tomography (CT), digital image processing (DIP) software and wedge splitting test (WST). The WST cubes were extracted from conventional 150 × 150× 600 concrete prisms and a groove and notch were carved on different faces in such a way that in half of the test specimens the fibers are oriented mostly perpendicular to the breaking surface and, in the other half, the fibers are mostly oriented parallel to the breaking surface. Fiber orientation was obtained using a CT device and DIP software from a miniprism extracted from the previously mentioned concrete prisms. The results show that there is a strong correlation between the crack-sewing fiber orientation on the one hand and fatigue life and crack opening rate per cycle on the other hand. Cubes with a higher percentage of fibers perpendicular to the crack surface (i.e., with a higher efficiency index) show a longer fatigue life and a lower crack opening rate per cycle, while cubes with a lower efficiency index show a shorter fatigue life and a higher crack opening rate per cycle.