Effect of carbon fiber on mechanical properties of reactive powder concrete exposed to elevated temperatures

• Published in: Journal of Building Engineering Vol. 42; p. 102503
• Main Authors: Raza, Syed Safdar, Qureshi, Liaqat Ali
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-10-2021
• Subjects: Carbon fiber; Elevated temperature; Hybrid fibers; Steel fiber; Ultra-high-performance concrete; SFRPC; Elevated temperature; CF; RPC; Hybrid fibers; CS; MOR; Ultra-high-performance concrete; SF; CFRPC; STS; Steel fiber; Carbon fiber
• ISSN: 2352-7102; 2352-7102
• DOI: 10.1016/j.jobe.2021.102503

An ultra-high-performance cement-based composite like reactive powder concrete (RPC) achieves its exceptional engineering properties due to a dense and homogenous microstructure. To improve the ductility and fire-resistance, RPC is often reinforced with a high volume of steel fibers (SF). Due to the issues of high density, low durability, and high conductivity; there is a need to study RPC with lightweight and durable fibers. In this research, the mechanical properties of RPC are studied with a single and hybrid fiber mixture of carbon fiber (CF) and conventional SF. The mechanical properties of plain and fiber-reinforced RPC were examined after exposure to 200oC, 400oC, 600oC, and 800oC temperatures for the 2 h. The results showed that CFRPC mechanically performs up to 85–90% potential of conventional SFRPC. Hybridization of 1.5% SF and 0.5% CF produced synergistic effects on the mechanical properties of RPC at both normal and elevated temperatures. After exposure to 800oC, CFRPC showed about 2, 4, and 5 times higher residual compressive, tensile, and flexural strength than plain RPC, respectively. Compressive strength-per-unit weight of CFRPC was notably higher than SFRPC.
•Effect of single and hybrid fibers on reactive powder concrete damaged by elevated temperatures.•Tensile properties of reactive powder concrete.•Single steel fiber produces better properties than single carbon fiber.•Hybrid steel-carbon fiber produces better properties than single steel or carbon fiber.