Journal of the Korea Institute of Building Construction (한국건축시공학회지)

The Korean Institute of Building Construction (한국건축시공학회)
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Quality of Recycled Fine Aggregate using Neutral Reaction with Sulfuric Acid and Low Speed Wet Abrader

  • Kim, Ha-Seog (Advanced Building Research Division Building Research Department, KICT) ;
  • Lee, Kyung-Hyun (Korea Atomic Energy Research & Institute) ;
  • Kim, Jin-Man (Department of Architecture, Kongju University)
  • Received : 2012.02.03
  • Accepted : 2012.07.15
  • Published : 2012.10.20
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Abstract

The use of recycled aggregate, even for low-performance concrete, has been very limited because recycled aggregate, which contains a large amount of old mortar, is very low in quality. To produce a high-quality recycled aggregate, removing the paste that adheres to the recycled aggregate is very important. We have conducted research on a complex abrasion method, which removes the component of cement paste from recycled fine aggregate by using both a low-speed wet abrasion crusher as a mechanical process and neutralization as chemical processes, and well as research on the optimal manufacturing condition of recycled fine aggregates. Subsequently, we evaluated the quality of recycled fine aggregate manufactured using these methods, and tested the specimen made by this aggregate. As a result, it was found that recycled fine aggregates produced by considering the aforementioned optimal abrasion condition with the use of sulfuric acid as reactant showed excellent quality, recording a dry density of 2.4 and an absorption ratio of 2.94. Furthermore, it was discovered that gypsum, which is a reaction product occurring in the process, did not significantly affect the quality of aggregates. Furthermore, the test of mortar using this aggregate, when gypsum was included as a reaction product, showed no obvious retarding effect. However, the test sample containing gypsum recorded a long-term strength of 25.7MPa, whereas the test sample that did not contain gypsum posted a long-term strength of 29.4MPa. Thus, it is thought to be necessary to conduct additional research into the soundness and durability because it showed a clear reduction of strength.

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References

  1. Ministry of environment. An annually trend of variation of waste. 2008.
  2. Ministry of environment. An annually trend of variation of waste. 2008.
  3. Lee DH. Construction & Transportation R&D Report. Korea Land &Housing Corporation. 2006.
  4. KICT, A preestimate to the amount of occurrence waste concrete in domestic. 2003.
  5. Minister of land, transport and maritime affairs. The standard of environmental management of recycled aggregate
  6. Metha PK, Paulo JM. Concrete Microstructure Properties and Materials. 3th rev. ed. New york (NY): Mc Graw Hill; 1993. p. 29-31.
  7. Kim JM. Optimum Abrasing Condition for Recycled Fine Aggregate Produced by Low Speed Wet Abrader Using Sulfur. Journal of the Korea Concrete Institute. 2008 Oct;20(5):557-63. https://doi.org/10.4334/JKCI.2008.20.5.557
  8. Metha PK, Paulo JM. Concrete Microstructure Properties and Materials. 3th rev. ed. New york (NY): Mc Graw Hill; 1993. p. 186-9.
  9. Sakiyama M, Oshio Y, Mitsuda T. Influence of Gypsum on the Hydrothermal Reaction of Lime-Quartz System and on the Strength of Autoclaved Calcium Silicate Product. Journal of the Society of Inorganic Materials. 2000;7(289):685-91.
  10. Chan CF, Sakiyama M, Mitsuda T. Kinetics of the CaO-Quartz-$H_{2}O$ Reaction at 120$^{\circ}C$ to 180$^{\circ}C$ in Suspensions. Cement and Concrete Research. 1978;8:1-6. https://doi.org/10.1016/0008-8846(78)90052-2
  11. Sato H, Grutzeck M. Effect of Starting Materials on the Synthesis of Tobermorite. Material Research Society Symposium Proceedings. 1992;245:235-40.
  12. Mitsuda T, Kiribayashi T, Sasaki K, Ishida H. Advances in Autoclaved Aerated Concrete. Balkema. Rotterdam. Netherlands. 1992. p. 11-8.
  13. Hemaly T, Mitsuda, Taylor HFW. Synthesis of Normal and Anomalous Tobermorite. Cement and Concrete Research. 1977;7:429-32. https://doi.org/10.1016/0008-8846(77)90071-0
  14. Choi DJ. The Experimental Study on The Compressive Strength of Concrete Using High Quality Recycled Fine Aggregate Produced by Sulphuric Water and Low Speed Wet Abrasional. Journal of the Korea Concrete Institute. Research conferences in Fall. 2008;20(2): 385-8.
  15. Metha PK, Paulo JM. Concrete Microstructure Properties and Materials. 3th rev. ed. New york (NY): Mc Graw Hill; 1993. p.146-7.
  16. Rosen MJ. Surfacants and Interfacial Phenomena. John W, Son. 1978. p. 206.
  17. Jawed I, Skalny J, Young JF. Structure and Performance of Cements. Barnes P. Applied Science Publishers; 1983. 240p.
  18. Metha PK, Paulo JM. Concrete Microstructure Properties and Materials. 3th rev. ed. New york (NY): Mc Graw Hill; 1993. p. 30-6.
  19. Jambor J. Pore Structure and Properties of Materials. Proc Conf. Prague. Vol. II. 1973. p. 30-6.
  20. Neville AM. Properties of Concrete, 4th rev. ed. New york (NY): John Wiley & Sons, Inc; 1995. p. 277-84.