전기로 슬래그를 활용한 인공리프용 친환경콘크리트의 공학적 성능 및 적용성 = Engineering Performance and Applicability of Eco-Friendly Concrete for Artificial Reefs Using Electric Arc Furnace Slags

국문 초록 (Abstract)

해양환경에 노출된 콘크리트는 육상에서 건설되는 콘크리트와 달리 해풍, 조력, 파도, 파랑 등에 의한 물리적 작용과 해수의 $SO_4{^{2-}}$, $Cl^-$ 및 $Mg^{2+}$ 이온 등에 의한 화학적 침식작용 및 동결융해 등 가혹한 환경에 노출되어 콘크리트의 내구성을 크게 저하시킨다. 해중 콘크리트의 대규모 시공은 콘크리트의 강도손실은 물론 알칼리(pH) 및 중금속 등 환경유해물질이 용출될 수 있어 이에 대한 충분한 검토와 연구가 필요한 실정이다. 본 연구에서는 전기로 환원슬래그로부터 CSA 자극제를 개발하고 전기로 산화슬래그를 콘크리트용 골재로 활용하여 인공리프용 친환경콘크리트를 개발하였다. 초기강도는 Normal concrete보다 낮게 나타나 친환경콘크리트의 초기강도 품질향상을 위한 추가적인 연구가 필요하였으며, 친환경콘크리트의 해수저항성은 양생일 1년 대비 평균 강도손실이 8~9% 발생하였다. 고함량 고로슬래그 미분말과 고비중 전기로 산화슬래그 골재를 사용한 친환경콘크리트를 동결융해저항성 재료로써 충분히 활용할 수 있는 가능성을 확인하였다. 친환경콘크리트의 중금속 용출특성은 콘크리트의 수화반응을 통한 경화과정에서 중금속 성분은 화학적 결합을 통해 고정화되기 때문에 환경유해성 기준 이하이거나 검출되지 않아 유해물질 용출에 안전하다는 것을 확인하였다.

다국어 초록 (Multilingual Abstract)

Unlike the concrete structure built on land, that exposed to the marine environment is greatly degraded in durability due to the exposure to not only the physical action caused by sea wind, tide, and wave, but also the harsh conditions, including the chemical erosion and freeze-thaw which result from $SO_4{^{2-}}$, $Cl^-$ and $Mg^{2+}$ ions in seawater. In the process of the large scaled construction of submerged concrete structures, of course environmental hazardous substance, such as alkaline (pH) and heavy metals, may be leached. Thus, this issue needs to be adequately reviewed and studied. Therefore, this study attempted to develop a CSA (Calcium Sulfo Aluminate) activator using electric arc furnace reducing slags, as well as the eco-friendly concrete for artificial reefs using electric arc furnace oxidizing slag as aggregate for concrete. The strength properties of the eco-friendly concrete exposed to the marine environment were lower than those of the normal concrete by curing 28 days. This suggest that additional studies are needed to improve the early strength of the eco-friendly concrete. With respect to seawater resistance of the eco-friendly concrete, the average strength loss against 1 year of curing days reached 8-9%. the eco-friendly concrete using high volume of ground granulated blast furnace slags and high specific gravity of electronic arc furnace oxidizing slag demonstrated the sufficient usability as a freeze-thaw resistant material. With respect to heavy metal leaching properties of the eco-friendly concrete, heavy metal substances were immobilized by chemical bonding in the curing process through the hydration of concrete. Thus, heavy metal substances were neither identified at or below environmental hazard criteria nor detected, suggesting that the eco-friendly concrete is safe in terms of leaching of hazardous substances.

참고문헌 (Reference)

1 박광필, "해수의 영향을 받은 콘크리트의 동결융해 특성" 한국콘크리트학회 23 (23): 23-30, 2011

2 이승헌, "전기로 슬래그를 치환한 고로 슬래그 시멘트의 특성" 한국세라믹학회 43 (43): 408-414, 2006

3 박조범, "자극제 종류에 따른 혼화재 대량사용 결합재의 수화분석" 대한건축학회 28 (28): 89-96, 2012

4 "Tests for chemical properties of aggregates, part 3 : Preparation of Eluates by Leaching of Aggregates"

5 World Steel Association, "Statistical Data"

6 Korea Iron & Steel Association, "Statistical Data"

7 DIN, "Leaching of solid materials-percolation method for the joint examination of the leaching behaviour of inorganic and organic substances"

8 EA NEN, "Leaching characteristics of moulded or monolithic building and waste materials, determination of leaching of inorganic components with the diffusion test, ‘The Tank Test’"

9 NSF, "Drinking water system components health effects"

10 "Characterization of waste-leaching-compliance test for leaching of granular waste materials and sludges, part 2 : One-stage Batch Test at a Liquid to Solids Ratio of 10 L/kg for Materials with a Particle Size Below 4 mm"