초저온에 노출된 초고성능 섬유보강 콘크리트의 역학적 성능 및 자기치유 성능 평가

초록

Herein we investigate the mechanical and self-healing properties of ultra-high-performance fiber-reinforced concrete (UHPFRC) at cryogenic temperatures. To this end, a comparative analysis was conducted on the effects of two types of reinforcing fibers, medium-length straight with a length of 19.5 mm and twisted fiber with a length of 30 mm, on the mechanical properties and resistance to cryogenic temperature. Then, the properties were compared with those of normal concrete (NC). In addition, the self-healing property of UHPFRC along with its micro-cracking behavior was examined. It was found that the UHPFRCs demonstrated better mechanical performance regardless of the temperature conditions: ambient, cryogenic, and recovered ambient temperatures. Furthermore, following exposure to cryogenic temperatures, no cracks were observed in the UHPFRC specimens, whereas several very tiny cracks were observed in the NC specimens. The self-healing process of UHPFRC by the formation of CaCO3 was observed by scanning electron microscopy.

키워드