Journal of the Korean Geotechnical Society (한국지반공학회논문집)

Korean Geotechnical Society (한국지반공학회)
권호 표지
DOI QR코드

DOI QR Code

Crushing Characteristics of Single Particle of Recycled Aggregate from Waste Concrete

폐콘크리트 순환골재의 단입자 파쇄 특성

  • Park, Sung-Sik (Dept. of Civil Eng., Kyungpook National Univ.) ;
  • Kim, Sang-Jung (Dept. of Civil Eng., Kyungpook National Univ.) ;
  • Moon, Hong-Duk (Dept. of Civil Eng., Gyeongnam National Univ. of Science and Technology)
  • 박성식 (경북대학교 공과대학 토목공학과) ;
  • 김상중 (경북대학교 공과대학 건축토목공학부) ;
  • 문홍득 (경남과학기술대학교 건설환경공과대학 토목공학과)
  • Received : 2016.06.27
  • Accepted : 2016.11.02
  • Published : 2016.12.31
Download PDF
⟨ Previous Next ⟩

Abstract

A single particle crushing test was carried out for recycled aggregates from waste concrete while demolishing various structures. When the recycled aggregates were used for backfill or road subbase materials, load-displacement and crushing characteristics were analyzed. The recycled aggregates with hydrates and aggregates were sorted into 40 mm size (75-40 mm) and 20 mm size (40-20 mm). At initial loading, their irregular surface was closed to and then crushed by loading plate. Such first crushing stage was called 'Surface crushing'. Further loading, some hydrate was crushed and detached from aggregate, and such process repeated several times. This state is called 'hydrate crushing'. The final state is called 'aggregate crushing' in which aggregate crushed and following load suddenly dropped down. As the load increased, such crushing cycle is repeated several times. The shapes of aggregates are round or square, and triangle or long shaped. Depending on their shapes and surface conditions, they crushed in different ways. The 63% of aggregates showed more than 50% load reduction due to aggregate crushing. The 90% load reduction occurred at 15% of aggregates. The 40 mm aggregate crushed at maximum load between 3.05-4.38 kN and 70% of crushed aggregates were less than 20 mm.

본 연구에서는 각종 구조물 철거 시 발생하는 폐콘크리트를 파쇄 처리하여 발생한 순환골재를 각종 토공 및 보조기 층용에 재활용 시 발생할 수 있는 하중-변위 및 파쇄 특성을 분석하기 위해 단입자 파쇄실험을 실시하였다. 수화물과 골재로 구성된 75mm 이하의 순환골재를 40mm 크기(75-40mm 사이)와 20mm 크기(40-20mm 사이)의 골재로 나누어 실험하였다. 순환골재에 하중이 증가할 경우 단입자의 파쇄 거동은 불규칙한 표면이 가압판에 밀착되면서 초기에 표면이 파쇄되는 '표면파쇄(Surface crushing)', 표면파쇄 이후 골재와 수화물이 분리되는 소규모 부분적 파쇄와 균열이 반복적으로 발생하는 '수화물파쇄(Hydrate crushing)', 수화물파쇄가 단계적으로 반복되다가 최대하중에서 골재가 파쇄되면서 하중이 급격히 감소되는 취성파괴인 '골재파쇄(Aggregate crushing)'의 순서로 파쇄 사이클(crushing cycle)이 진행되었다. 한편, 하중이 지속적으로 증가함에 따라 이러한 파쇄 사이클은 수 차례 반복되는 경향을 보였다. 순환골재의 형상은 둥글거나 사각형에 가깝거나, 삼각형 또는 길쭉한 형태로 표면상태나 형상에 따라 파쇄 형상이 다르게 나타났다. 골재파쇄(최대 파쇄)에서 취성파괴로 하중이 감소되는 비율인 파쇄하중 감소율은 50% 이상인 경우는 63% 정도이며, 90% 이상인 경우도 15% 정도로 나타났다. 40mm 단입자는 최대하중 3.05~4.38kN 정도에서 대부분 파쇄되어 작은 입자로 분리되며, 세립화된 단입자 개수를 기준으로 20mm 이하의 분포비율은 약 70% 정도였다.

Keywords

References

  1. Cho, S. A. (2009), Study on Shear Behavior and Particle Crushing with Respect to Particle Shape, Master thesis, Konkuk University.
  2. Ham, T. G., Cho, Y. S., and Kim, Y. S. (2004), "A Study on the Compression Characteristics of Decomposed Granite Soil Based on Single Particle Crushing Property", Journal of the Korean Geotechnical Society, Vol.20, No.8, pp.103-111.
  3. Ham, T. G. and Kim, U. G. (2008), "Influence of Water on Compression Characteristic of Decomposed Granite Soil Based on Single Particle Crushing Strength", Journal of the Korean Geotechnical Society, Vol.24, No.11, pp.101-109.
  4. Jeong, S. A. (2010), Characteristics of Shear Behavior according to State of Particle Bonding and Crushing, Master thesis, Konkuk University.
  5. Jeong, S. A., Kim, E. K., and Lee, S. W. (2010), "Applicability of Particle Crushing Model by Using PFC", Journal of Korean Geosynthetics Society, Vol.9, No.1, pp.47-57.
  6. Kang, S. C., Kim, G. H., Wi, J. H., Ahn, T. B., Lee, D. S., and Choi, H. S. (2015), "Effect of Particle Breakage on Compaction and Thermal Resistivity of Concrete-based Recycled Aggregates", Journal of the Korean Geotechnical Society, Vol.31, No.10, pp. 17-28.
  7. Kim, H. U. (2014a), Shear Strength Characteristics by the Particle Crushing in the Decomposed Pocheon Granite Soil, Master thesis, Daejin University.
  8. Kim, J. H. (2016), Study on the pH of Recycle Aggregates, Master Thesis, Kumoh National Institute of Technology.
  9. Kim, S. J., Ji, W. B., Yi, C. T., and Han, H. S. (2014a), "A Change of Porewater Pressure under Particle Crushing of Carbonate Sand of Sabkha Layer", Journal of the Korean Geotechnical Society, Vol.30, No.2, pp.19-32. https://doi.org/10.7843/KGS.2014.30.2.19
  10. Kim, Y. J. (2014b), Quality Assessment of Recycled Aggregate Concrete using Microscopic Studies, Ph.D thesis, Hanyang University.
  11. Kim, J. H., Han, M. C., and Han, C. G. (2014b), "Strength Development of the Concrete Incorporating Blast Furnace Slag and Recycled Aggregate as Alkali Activator", Journal of Korean Recycled Construction Resources Institute, Vol.2, No.2, pp.107-114. https://doi.org/10.14190/JRCR.2014.2.2.107
  12. KS F 2541 (2002), Testing method for determination of aggregates crushing value.
  13. Kwak, J. M. (1999), "A Basic Study on Crushability of Sands and Characteristics of Particle Strength", Journal of the Korean Geotechnical Society, Vol.15, No.15, pp.193-204.
  14. Kwon, J. H., Kim, S. W., and Park, B. S. (2013), "Study on the Reinforced Retaining Wall using the Backfill of Recycled Aggregate", Journal of Korean Society of Environmental Technology, Vol.14, No.2, pp.128-134.
  15. Lade, P. V., Yamamuro, J. A., and Bopp, P. A. (1996), "Significance of Particle Crushing in Granular Materials", Journal of Geotechnical Engineering, Vol.122, No.4, pp.309-316. https://doi.org/10.1061/(ASCE)0733-9410(1996)122:4(309)
  16. Lee, K. L. and Farhoomand, I. (1967), "Compressibility and Crushing of Granular Soil in Anisotropic Triaxial Compression", Canadian Geotechnical Journal, Vol.4, No.1, pp.68-86. https://doi.org/10.1139/t67-012
  17. Lee, W. K., Choi, J. O., and Jung, Y. W. (2015), "Effect of the Amount of Attached Mortar of Recycled Aggregates on the Properties of Concrete", Journal of Korean Recycled Construction Resources Institute, Vol.3, No.2, pp.132-139. https://doi.org/10.14190/JRCR.2015.3.2.132
  18. Lee, J. Y., Chun, H. P., Jeong, W. C., and Lim, H. S. (2008), "A Study on Utilization of Recycled Aggregates as Lateral Drain for Soft Ground Improvement", Journal of the Korean Geotechnical Society, Vol.24, No.10, pp.5-15.
  19. Lee, J., Lee, B. C., Cho, Y. G., and Jung, S. H. (2016), "Chloride Diffusivity of Concrete using Recycled Aggregate by Strength Levels", Journal of the Korea Institute of Structural Maintenance and Inspection, Vol.20, No.2, pp.102-109.
  20. Lee, J. C., Song, T. H., Lee, S. H., and Kim, J. B. (2011), "A Study on the Optimization of Recycled Aggregate Alkalinity Reducing Facility in the Field", Journal of Korean Recycled Construction Resources Institute, Vol.6, No.3, pp.53-60.
  21. Lobo-Guerrero, S. and Vallejo, L. E. (2005), "Analysis of Crushing of Granular Material under Isotropic and Biaxial Stress Conditions", Soils and Foundations, Vol.45, No.4, pp.79-87. https://doi.org/10.3208/sandf.45.4_79
  22. McDowell, G. R. and Bolton, M. D. (1998), "On the Micromechanics of Crushable Aggregates", Geotechnique, Vol.48, No.5, pp.667-679. https://doi.org/10.1680/geot.1998.48.5.667
  23. Ministry of Land, Infrastructure and Transport (2013), Quality Standards for Recycled Aggregate.
  24. Nakata, Y., Hyodo, M., Hyde, A. F. L., Kato, Y., and Murata, H. (2001), "Microscopic Particle Crushing of Sand Subjected to High Pressure One-Dimensional Compression", Soils and Foundations, Vol.41, No.1, pp.69-82. https://doi.org/10.3208/sandf.41.69
  25. Park, B. S., Sim, D. S., Lee, H. K., and Jung, G. S. (2011), "Installation Resistance Test for the Reinforced Materials with Compaction of Recycled Aggregate", Proc. of Korean Society of Hazard Mitigation.
  26. Shin, J. L., Kim, W. S., Baek, S. M., Kang, H. K., and Kwak, Y. K. (2015), "Structural Performance Evaluation of Steel Fiber-Reinforced Concrete Beams with Recycled Coarse Aggregates", Journal of the Korea Concrete Institute, Vol.27, No.3, pp.215-227. https://doi.org/10.4334/JKCI.2015.27.3.215
  27. Song, T. H., Lee, J. C., and Lee, S. H. (2011), "A Study on the pH Characteristic of Recycle Aggregate According to Test Methods and Elapsed Time", Journal of Korean Recycled Construction Resources Institute, Vol.6, No.3, pp.61-68.
  28. Wi, J. H., Hong, S. Y., Lee, D. S., Park, S. W., and Choi, H. S. (2011), "Evaluation of Compaction and Thermal Characteristics of Recycled Aggregates for Backfilling Power Transmission Pipelines", Journal of the Korean Geotechnical Society, Vol.27, No.7, pp.17-33.
  29. Yoon, G. L., Yoon, Y. W., Kang, O. R., You, S. K., and Lee, K. H. (2008), "Shear Strength Characteristics of Recycled-aggregate Porous Concrete Pile for Soft Ground Improvement", Journal of the Korean Geotechnical Society, Vol.24, No.12, pp.75-84.

Cited by

  1. 다짐으로 인한 순환골재의 파쇄 및 공학적 특성에 관한 연구 vol.33, pp.12, 2016, https://doi.org/10.7843/kgs.2017.33.12.35