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An Experimental Study on Thermal Properties according to Rock Types of the Crushed Aggregates for Concrete

콘크리트용 부순 골재의 암석 종류별 열적 특성에 관한 실험적 연구

  • Received : 2016.01.20
  • Accepted : 2016.03.29
  • Published : 2016.04.30

Abstract

The analysis of the petrologic characteristics and thermal properties of crushed aggregates for concrete such as granite, gneiss, dolomite, shale and andesite found that rock-forming minerals decided the thermal properties of the aggregates. The thermal expansion coefficients of aggregates containing lots of quartz increased rapidly at $573^{\circ}C$ due to quartz transition. The mass of aggregate containing carbonate minerals decreased rapidly at $750^{\circ}C$ due to decarboxylation, while its specific heat capacity increased relatively. The mass of aggregates containing hydrated silicate minerals decreased more significantly and their specific heat capacities were greater when compared with aggregates containing feldspar or quartz. It is deduced that the hydroxyle group (OH) in hydrated silicate dissolved as its bond became loose at high temperatures. Aggregates containing mafic minerals turned red at high temperatures due to oxidation response. And, the comparison of cooling methods showed that rapid cooling using water resulted in more reduction in aggregate mass than slow cooling at room temperatures.

Keywords

Acknowledgement

Supported by : 국토교통부

References

  1. British Standard (2004). Eurocode 2: Design of concrete structures Part 1-2 : General rules-Structural fire design, UK, British Standards.
  2. Chin, H. I., Min, K. W., Baek, H. J., & Yeon, K. S. (1997). Lithological and Mechanical Characteristics of Crushed Limestone Aggregates. Magazine of the Korea Concrete Institute, 9(3), 119-126. https://doi.org/10.22636/MKCI.1997.9.3.119
  3. Chin, H. I., Min, K. W., & Yeon, K. S. (1998). Mineralogical and Mechanical Properties of Some Rocks as Aggregates and Their Suitability for Concrete. Magazine of the Korea Concrete Institute, 10(4), 183-193. https://doi.org/10.22636/MKCI.1998.10.4.183
  4. Clauser, C., & Huenges, E. (1995). Thermal conductivity of rocks and minerals, Rock Physics and Phase Relations : A Handbook of Physics Constants, 105-126.
  5. Hong, S. S., Lee, C. B., Park, D. W., Yang, D. Y., Kim, J. Y., Lee, B. T., & Oh, G. C. (2004). Geology and Distribution of Crushed Aggregate Resources in Korea, Econ. Environ. Geol., 37(5), 555-568.
  6. International Code Council (2015). 2015 International Building Code, USA, International Code Council.
  7. Korea Concrete Institute (2009). Standard Concrete Construction Specification.
  8. Lee, S. B. (2002). Application and quality property of aggregate for concrete. Magazine of the Korea Concrete Institute., 14(2), 123-131.
  9. Meyers, S. L. (1951). How temperature and moisture changes may affect the durability of concrete. Rock Products, 153-157,
  10. Neville, A. M. (2004). Properties of concrete, John Wiley & Sons Ltd., Chichester, UK
  11. Rhoades, R., & Mielenz, R. C. (1946). Petrography of concrete aggregates, Journal of American Concrete Institute, 42(6), 581-600.
  12. Xing, Z., Neaucour, A., Hebert, R., Noumowe, A., & Ledesert, N. (2011). Influence of the nature of aggregates on the behaviour of concrete subjected to elevated temperature. Cement and Concrete Research 41, 392-402 https://doi.org/10.1016/j.cemconres.2011.01.005