논문 상세보기
pp.127-134
본 연구는 고강도 콘크리트의 복합유기섬유 혼입률 변화 및 ISO와 RABT의 가열온도곡선 변화에 따른 내화시험을 실시한 후 폭렬방지성상 및 잔존압축강도 특성 등을 분석한 것으로, 그 결과를 요약하면 다음과 같다. 복합유기섬유 혼입 콘크리트의 기초적 특성으로 유동성은 섬유혼입률이 증가할수록 직선적으로 저하하는 경향이었고, 공기량은 약간의 증가 또는 감소의 경향은 있었으나 큰 차이 없었으며, 28 일 압축강도는 완만한 감소경향을 나타내었다. 내화특성으로, RABT 가열온도곡선의 경우는 ISO 가열온도곡선에 비해 복합유기섬유 혼입률이 많은 범위까지 폭렬양상을 나타내었으나, 주로 박리폭렬일뿐 내부까지 극심한 폭렬양상은 발생하지 않았다. 결국 W/B 25%인 고강도 콘크리트의 경우 ISO 가열온도곡선은 섬유의 혼입률 0.04%이상에서, RABT 가열온도곡선의 경우는 섬유의 혼입률 0.10%이상에서 폭렬이 방지되는 것으로 나타났다. 가열온도곡선 변화에 따른 질량감소율은 폭렬이 방지된 경우 ISO 가열온도곡선은 7%전후, RABT 가열온도곡선은 9%전후로 나타났다. 가열온도곡선변화에 따른 잔존압축강도율은 폭렬이 방지된 경우 ISO 가열온도곡선은 50%~60%, RABT 가열온도곡선은 30%~35%를 나타내었다.
This study investigated their properties of spalling resistance and residual compressive strength after fire test corresponding to various ISO, RABT heating curves, and contents of hybrid organic fiber of high strength concrete. The results were summarized as following. As fundamental characters of concrete with hybrid organic fiber, the flowability was directly declined as the increase of fiber contents, and air contents were decreased or increased a little bit, but there was not big difference. The compressive strength was gradually declined sluggishly at 28 days. As properties of fire resistance, in case of RABT heating curves, compare with ISO heating curves a spalling aspect showed till range that has much contents of hybrid organic fiber, but they are mostly peeling spalling, which means spalling aspect didn't happen to inside. In conclusion, in case of W/B 25% high strength concrete, the spalling was prevented over 0.04% of contents of fiber at ISO heating curve and over 0.10% of contents of fiber at the RABT heating curve. In case of spalling was prevented, mass reduction rate according to the change of heating temperature curves showed around 7% at ISO heating curves and around 9% at RABT heating curves. The residual compressive strength rate corresponding to the change of heating temperature curves showed 50%~60% at ISO heating temperature curves and 30%~35% at RABT heating temperature curves in case of spalling was prevented.
