DOI QR코드

DOI QR Code

Physical Properties of Shale Aggregate and Characteristics of Concrete in Replacement Ratio in Daegu-Kyeongbuk Region

대경권 셰일 골재의 물성 평가 및 치환율 변화에 따른 콘크리트의 특성

  • Lee, Seung-Han (Department of Civil Engineering, Keimyung University) ;
  • Jung, Yong-Wook (Advanced Construction Materials Testing Center, Keimyung University) ;
  • Yeo, In-Dong (Department of Civil Engineering, Keimyung University) ;
  • Choi, Jong-Oh (Department of Civil Engineering, Keimyung University) ;
  • Bae, Su-Ho (Department of Civil Engineering, Andong National University)
  • Received : 2012.08.22
  • Accepted : 2012.11.08
  • Published : 2012.11.30

Abstract

Sedimentary rocks dug up in construction fields are mostly stockpiled for landfill disposal, leading to an increase in construction costs and construction inefficiency. After screening, some of the sandstone can be used as aggregate; however, most of the shale ends up as industrial waste in practice. In this study, to stabilize the demand and develop resources for alternative aggregates of concrete, the potential use of shale, which is widely distributed in the Daegu-Kyeongbuk region, as a concrete aggregate was evaluated. Red and black shale exported from a Daegu excavation site was selected for use in the experiments and evaluated by comparing with hornfels, which is widely used as a coarse aggregate and is a type of andesite and metamorphosed sedimentary rock. The physical properties of the aggregate were evaluated in accordance with the test methods of KS F 2527 "crushed concrete aggregate," and the compressive strength against the shale aggregate replacement ratio was measured. The compressive strength of the concrete after 28 days was 30.8 MPa when the black shale replaced 100% of the aggregate in the concrete and 31.1 MPa when the red shale replaced 100% of the aggregate in the concrete. Compared with the compressive strength of 37.5 MPa for concrete prepared by using plain aggregate, using shale as a substitute for the aggregate produced an average compressive strength that was 82% of normal concrete.

건설공사 현장에서 발생하는 버럭 중 퇴적암은 대부분 야적, 매립 등으로 폐기하고 있어 공사비의 증대 및 시공 비효율화의 원인이 되고 있다. 이 중 일부 사암의 경우 선별하여 골재로 활용하기도 하지만, 셰일은 대부분 산업폐기물로 매립하고 있는 실정이다. 이에 본 연구에서는 골재수급 안정화 및 콘크리트용 대체골재 자원 개발의 일환으로 대경권에 널리 분포하고 있는 셰일의 콘크리트용 골재 활용 가능성을 평가하였다. 실험에 사용된 셰일은 대구시 터파기 공사현장에서 반출되는 레드셰일과 블랙셰일을 선정하였으며, 콘크리트용 굵은 골재로 널리 사용되는 안산암과 변성퇴적암의 일종인 혼펠스와 비교함으로써 셰일의 콘크리트용 골재 활용성을 검토하였다. 골재의 물성평가는 KS F 2527 "콘크리트용 부순 골재"에서 규정한 시험방법에 준하여 실시하였으며, 셰일 골재의 치환율 변화에 따른 재령별 압축강도를 측정하였다. 실험결과, 절대건조밀도는 블랙셰일에서 $2.59g/cm^3$, 레드셰일에서 $2.62g/cm^3$으로 나타났으며, 흡수율은 블랙셰일에서 1.93%, 레드셰일에서 1.43%로 나타나 콘크리트용 굵은 골재 사용기준을 만족하는 것으로 나타났다. 셰일 골재의 치환율에 따른 재령 28일 압축강도는 블랙셰일을 100% 치환하여 제조한 콘크리트의 경우 30.8MPa, 레드셰일을 100% 치환한 경우 31.1MPa로 나타나 Plain 골재를 사용하여 제조한 콘크리트의 압축강도 37.5MPa과 비교하여 약 82%의 강도 수준을 나타내었다.

Keywords

References

  1. Korea Institute of Geology, Mining & Materials, Evaluation of Aggregate Resources at Kyungsang Provinces II, p.736, Ministry of Trade and Industry, 1995.
  2. Kim Jin Cheol, "Evaluation of Usability for Sub - base of Muddy Stone produced on Site" Journal of Korean Society of Road Engineers, Vol. 7 No. 3, pp. 93-100, 2005.
  3. Young Huy Lee et al., "Shear Strength Characteristics of Rock Specimens by Triaxial Compression Tests" Journal of Korean Society of Civil Engineers, Vol. 1998 No. 2, pp. 131-134, 1998.
  4. Kim Young Soo et al., "A Study on the Resistance of Freezing-Thawing for the Material of Concrete or Asphalt Using Smashed Rock" Journal of Korean Geo-environment Society, Vol 3 No. 2, pp. 35-47, 2002.
  5. Yong-Wook Jung et al., "The Influence of Fineness Modulus of Fine Aggregate and Grain Shape of Coarse Aggregate on the Properties of High Flowing Concrete" Journal of Korea Concrete Institute, Vol. 17 No.5, pp. 785-792, 2005. https://doi.org/10.4334/JKCI.2005.17.5.785
  6. Tuk Ki Min et al., "Los Angeles Abrasion Test for Estimating Engineering Index on the Sedimentary Rocks of Kyeongsang Basin" Journal of Korean Geotechnicla Society, Vol. 23 No. 11, pp. 15-26, 2007.
  7. Kim Young Soo et al., "A Study on the Mechanical Characteristics of Aging Effect in the Sedimentary Rock's Aggregates" Journal of Korean Society of Civil Engineers, Vol. 1999 No. 4, pp. 137-140, 1999.
  8. Koh Kyung Taek et al., "Effect of the Grain Shape of Crushed Sand on Concrete Qualities", Journal of Korean Society of Civil Engineers, Vol. 24 No. 1A, pp. 229-236, 2006.
  9. Park Cho-Bum et al., "Influence of Qualities of Crushed Sand on Properties of Concrete using Mixed Fine Aggregate" Journal of the Architectural Institute of Korea : Construction, Vol. 23 No. 8, pp. 115-122, 2007.