Journal of the Korea Institute of Building Construction (한국건축시공학회지)

The Korean Institute of Building Construction (한국건축시공학회)
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The Status of Clay Minerals in Aggregates and Their Effect on the Concrete Performance

골재에 포함된 토분의 현황 조사 및 콘크리트의 성능에 미치는 영향

  • Kim, In (Department of Architectural Engineering, Cheong ju University) ;
  • Han, Min-Cheol (Department of Architectural Engineering, Cheong ju University)
  • 김인 ;
  • 한민철
  • Received : 2024.04.25
  • Accepted : 2024.06.20
  • Published : 2024.08.20
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Abstract

The Korean Industrial Standard(KS) KS F 2527("Aggregates for Concrete") does not explicitly define criteria for clay mineral content in aggregates. This lack of clear quality standards and testing methodologies is further compounded by a scarcity of relevant research within both academic and industrial spheres. Consequently, the construction industry, encompassing both aggregate production and utilization, often overlooks the management of clay mineral content due to its perceived economic implications. This study addresses this gap by investigating the current state of regulations concerning clay mineral content in aggregates, exploring the causes of its occurrence, and evaluating its impact on concrete performance. The chemical composition of the clay minerals was determined to primarily consist of Al2O3, Fe2O3, and SiO2, which are commonly found in clay. X-ray diffraction(XRD) analysis revealed that the predominant clay minerals were montmorillonite and illite, both known for their high absorption capacity. An examination of domestic and international standards for clay mineral content in aggregates demonstrated that the density and absorption rate specifications outlined in KS F 2527("Aggregates for Concrete") only offer indirect estimations of clay mineral levels. Furthermore, the investigation into the influence of clay mineral content on concrete performance suggests that a higher clay mineral content necessitates a corresponding increase in the unit quantity of aggregates to maintain adequate workability. This, however, has a detrimental effect on the compressive strength of the concrete.

토분에 대한 기준은 한국산업표준(KS)의 KS F 2527(콘크리트용 골재)에서 규정하고 있지 않으며 명확한 품질기준과 시험방법이 없으며 학계 및 산업계의 관련 연구도 부족한 상황이다. 또한 골재를 생산하는 업계와 사용하는 업계등 실무에서는 토분 문제가 경제성과 직결됨으로 운영상 관리가 되지 않는 실정이다. 따라서 본 연구에서는 골재 토분 문제에 대한 현황 및 관련 기준, 발생원인을 조사하고 토분이 콘크리트에 미치는 영향에 대해 연구 한 결과 토분의 화학적 조성은 점토에서 흔히 조성되는 Al2O3, Fe2O3, SiO2로 나타났으며 XRD 분석결과 흡수성이 높은 몬모릴나이트와 일라이트 광물로 구성되어 있는 것으로 확인하였다. 또한 국내·외 토분의 품질규정 조사결과 KS F 2527(콘크리트용 골재)에서 제시하고 있는 밀도 및 흡수율은 토분의 함유량의 어느 정도에 대하여 간접적으로 유추해 볼 수 있는 수치에 불과한 실정이다. 또한 토분이 콘크리트의 성능에 미치는 영향을 분석한 결과 토분의 첨가량이 증가함에 따라 콘크리트의 유동성을 확보하기 위해서는 단위수량 증가가 필요하며 이로인해 압축강도 또한 감소 되는 것으로 사료된다.

Keywords

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