Mechanical Properties of Aramid/Carbon Hybrid Fiber-Reinforced Concrete

• Published in: Materials Vol. 14; no. 19; p. 5881
• Main Authors: Li, Yeou-Fong, Wang, Hsin-Fu, Syu, Jin-Yuan, Ramanathan, Gobinathan Kadagathur, Tsai, Ying-Kuan, Lok, Man Hoi
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 08-10-2021; MDPI
• Subjects: Aggregates; aramid fiber; Aramid fiber reinforced concretes; Aramid fiber reinforced plastics; carbon fiber; Carbon fibers; Cement; compressive strength; concrete; Concrete mixing; Corrosion resistance; Coupling agents; Crack propagation; flexural strength; High temperature; Impact resistance; Impact tests; Kevlar (trademark); Mechanical properties; Metal fatigue; Optical microscopes; Reinforced concrete; Research methodology; splitting strength; Tensile strength; Taiwan
• ISSN: 1996-1944; 1996-1944
• DOI: 10.3390/ma14195881

In this study, aramid fiber (Kevlar® 29 fiber) and carbon fiber were added into concrete in a hybrid manner to enhance the static and impact mechanical properties. The coupling agent presence on the surface of carbon fibers was spotted in Scanning Electron Microscope (SEM) and energy-dispersive X-ray spectroscopy (EDS) graphs. The carbon fiber with a coupling agent affected the mechanical strength of the reinforced concrete. At 1% fiber/cement weight percentage, the hybrid fiber-reinforced concrete (HFRC) prepared using Kevlar fiber and carbon fiber of 12 and 24 mm in length under different mix proportions was investigated to determine the maximum mechanical strengths. From the test results, the mechanical strength of the HFRC attained better performance than that of the concrete with only Kevlar or carbon fibers. Foremost, the mix proportion of Kevlar/carbon fiber (50–50%) significantly improved the compressive, flexural, and splitting tensile strengths. Under different impact energies, the impact resistance of the HFRC specimen was much higher than that of the benchmark specimen, and the damage of the HFRC specimens was examined with an optical microscope to identify slippage or rupture failure of the fiber in concrete.