Journal of the Korea institute for structural maintenance and inspection (한국구조물진단유지관리공학회 논문집)

Korea Institute for Structural Maintenance Inspection (한국구조물진단유지관리공학회)
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Effects of Micropores on the Freezing-Thawing Resistance of High Volume Slag Concrete

슬래그를 다량 치환한 콘크리트의 동결융해 저항성능에 미치는 미세공극의 영향

  • Received : 2015.02.27
  • Accepted : 2015.04.30
  • Published : 2015.07.30
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Abstract

In this study, effects of micropores on the freezing-thawing resistance of high volume slag concrete are reviewed. Concrete was made with slag which contains the ground granulated blast furnace slag(GGBS) and the pig iron preliminary treatment slag(PS) by replacing 0, 40, 70 %, then compressive strength, freezing-thawing resistance, micropores were reviewed. Also, specified design strength, target air contents were set. Deterioration was induced by using 14-day-age specimen which has low compressive strength for evaluating deterioration by freeze-thawing action. As results of the experiment, despite of specified design strength which has been set similarly and ensured target air contents, the pore size distribution of the concrete showed different results. Micropores in GGBS70 specimen have small amount of water which is likely to freeze because there is small amount of pore volume of 10~100 nm size at 0 cycle which has not been influenced by freezing-thawing. For these reasons, it was confirmed that the freezing-thawing resistance performance of GGBS70 is significantly superior than other specimens because relatively small expansion pressure is generated compared to the other specimens.

본 연구에서는 슬래그를 다량 치환한 콘크리트의 동결융해 저항성능에 미치는 미세공극의 영향을 검토하였다. 콘크리트는 용선예비처리 슬래그가 포함된 고로슬래그 미분말을 0, 40, 70 % 치환하여 제조하였으며 압축강도 특성 및 동결융해 저항성능과 미세공극을 검토하였다. 또한 설계기준강도와 목표공기량을 설정하고, 동결융해 작용에 따른 열화를 확인하기 위하여 재령 14일의 낮은 압축강도로 인한 내력저하를 유도하였다. 실험결과, 설계기준강도를 유사하게 설정하고 목표공기량을 확보하였음에도 불구하고 콘크리트의 미세공극 분포가 상이한 결과를 나타내었다. GGBS70 시험체는 동결융해를 받지 않은 초기 0사이클에서 10~100 nm 크기의 공극량이 가장 적어 공극 내 동결할 수 있는 물의 양이 적을 것으로 판단된다. 이러한 이유로 다른 시험체에 비해 동결팽창압력이 상대적으로 작기 때문에 동결융해 저항성능이 우수한 것으로 판단된다.

Keywords

References

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