Manufacturing artificial lightweight aggregates using coal bottom ash and its application to the lightweight-concretes

석탄 바닥재를 이용한 인공경량골재의 제조 및 경량 콘크리트에 적용

  • Kim, Kang-Duk (Department of Materials Engineering, Kyonggi University) ;
  • Kang, Seung-Gu (Department of Materials Engineering, Kyonggi University)
  • Published : 2008.10.31

Abstract

The artificial lightweight aggregate (ALA) was manufactured in a rotary kiln at $1125^{\circ}C$ using green body formed by pelletizing the batch powder composing of coal bottom ash (CBA) produced from power plant, clay and dredged soil (DS). The TCLP (Toxicity characteristic leaching procedure) results showed that the dissolution concentration of heavy metal ions of ALA fabricated in this study was below the limitation defined by the enforcement regulations of wastes management law in Korea. The ALA containing 60$\sim$70 wt% CBA had a bulk density of 1.45$\sim$1.49 and a water absorption of 17.2$\sim$18.5 %. The impact values for oven-dry state and saturated-surface dry state of ALA were 27.4$\pm$1.3 and 23.4$\pm$2.6 % respectively. The 28-days compressive strength of concrete made with various ALA was $22.7\sim27.8 N/mm^2$. The slump of concrete with ALA containing CBA 60 and 70 wt% were 7.9 and 14.3 cm respectively. The unit weight of concrete made with any ALA fabricated in this study was satisfied with the standard specifications of lightweight concrete for the civil engineering and construction presented by Korea as below $1.84 ton/m^3$.

화력발전소에서 발생하는 석탄 바닥재(Coal bottom ash)를 준설토(Dredged soil) 및 적점토(Clay)와 혼합하여 조립기(Pelletizer)로 성형 후, 이를 로타리 킬른에서 $1125^{\circ}C$에서 소성하여 인공경량골재를 제조였다. 제조된 인공경량골재에 대한 중금속 용출 실험(TCLP) 결과, 폐기물 관리법 시행규칙의 중금속 검출량 기준치 이하로 나타났다. 바닥재가 60$\sim$70 wt% 첨가된 인공경량골재는 부피비중 1.45$\sim$1.49, 흡수율 17.2$\sim$18.5%의 값을 나타냈으며, 골재충격시험결과 건조 상태와 표건 상태의 충격값이 각각 27.4$\pm$1.3 및 23.4$\pm$2.6%를 나타내었다. 인공경량골재를 이용하여 제조된 콘크리트 공시체의 28일 압축강도는 첨가된 골재종류에 따라 $22.7\sim27.8 N/mm^2$ 이었다. 바닥재가 60 및 70% 첨가된 골재를 사용한 콘크리트의 슬럼프 값은 각각 7.9와 14.3 cm를 나타내었고, 단위용적질량은 골재조성에 상관없이 $1.84 ton/m^3$ 이하를 나타내어 토목 건축공사 표준시방서에 제시된 경량콘크리트 특성을 만족하였다.

Keywords

References

  1. Y.I. Koh, H.T. Kim and J.H. Noh, "Consideration on utilization of coal ash mixed with fine particle as drain materials for soft ground", Kor. Geo-Enviro. Soc. Workshop (2005) 69
  2. G.L. Yoon, C.W. Lee and W.S. Jeong, "Korean environmental standards for beneficial use of dredged materials", J. of the Korean Geotechnical Soc. 24(5) (2008) 5
  3. F. Canpolat, K. Yilmaz and M.M. Kse, "Use of zeolite, coal bottom ash and fly ash as replacement materials in cement production", Cem. & Conc. Res. 34 (2004) 731 https://doi.org/10.1016/S0008-8846(03)00063-2
  4. O. Ozkan, I. Yuksel and O. Muratoglu, "Strength properties of concrete incorporating coal bottom ash and granulated blast furnace slag", Waste Management 27 (2007) 161 https://doi.org/10.1016/j.wasman.2006.01.006
  5. C. Kang, K.W. Kang, E.G. Kawg and G.C. Jung, "Site application of the light weight foamed concrete partition wall using bottom ash", Proceeding of Architectural Institute of Kor. 25(1) (2005) 369
  6. S.J. Park, J.D. Lim and S.H. Park, "Study of monitoring for change of marine environment by dumping dredged materials", J. of the Kor. Soc. Marin Enviro. & Safety (2007) 15
  7. Y.T. Kim, Y.K. Kwon and H.J. Kim, "Comparison of compressive behavior characteristics between un-reinforced and reinforced lightweight soils for recycling of dredged soils", J. of Ocean Eng. & Tech. 19(6) (2005) 44
  8. S.S. Kim, B.I. Kim, S.J. Han and H.Y. Shin, "Strength characteristics of light-weighted soils mixed with EPS and dredged soils", J. of Kor. Soc. for Railway 5(2) (2002) 61
  9. K.D. Kim and S.G. Kang, "Manufacturing artificial lightweight aggregates using coal bottom ash and clay", J. Kor. Cry. Growth & Cry. Tech. 17(6) (2007) 277
  10. KS F 2581; Testing method for determination of aggregates impacting value-Method of test for production control of aggregates, Korean Standards Association (2003)
  11. Korea concrete institute, "New Concrete Engineering" Kimundang, Korea (2007)
  12. Architectural Institute of Korea, "Standard specification of building construction", Kimundang, Korea (2006)