DOI QR코드

DOI QR Code

The Degree of Hydration and Mechanical Properties of High Volume Fly Ash Cement

하이볼륨 플라이애시 시멘트의 수화도 및 역학적 특성

  • 차수원 (울산대학교 토목공학과) ;
  • 최영철 (가천대학교 토목환경공학과)
  • Received : 2022.09.05
  • Accepted : 2022.10.26
  • Published : 2022.10.30

Abstract

Recently, there has been a growing interest in reducing greenhouse gases in all industrial fields. In the construction industry, studies have been conducted for the use of high-volume fly ash concrete to replace cement with fly ash. Quantitative measurements of cement hydration and fly ash reactivity enable a clear understanding of the strength development mechanism of high-volume fly ash concrete. It is very difficult to describe the reactivity in a simple way because the hydration and pozzolanic reactions of cement paste containing fly ash are very complex and the composition of the hydration product cannot be accurately determined. This study investigated the hydration and mechanical properties of high volume fly ash (HVFA) cement according to the substitution rate of fly ash (FA). The hydration degree of cement and the reactivity of FA were evaluated through the selective dissolution method and the non-evaporable water content of the paste according to age. In addition, compressive strength was measured using HVFA mortar specimens according to age. As a result of the experiment, as the substitution rate of fly ash increased, the hydration degree of cement increased, but the reactivity of FA decreased.

최근, 전세계적으로 온실 가스의 저감에 관심이 높아지면서 건설 산업에서도 FA를 대량 치환하는 HVFAC의 사용을 위한 연구가 수행되고 있다. 시멘트의 수화도와 FA 반응도의 정량적인 측정은 HVFAC의 강도발현 메커니즘을 명확히 이해할 수 있게 한다. FA가 포함된 시멘트 페이스트의 수화 및 포졸란 반응은 매우 복잡하고 수화 생성물의 조성을 정확하게 결정할 수 없으므로 간단한 방법으로 반응도를 설명하는 것은 매우 어렵다. 따라서, 이 연구는 재령에 따른 하이볼륨 FA 시멘트의 수화 특성을 조사하였다. 시멘트의 수화도와 FA의 반응도는 재령에 따른 선택용해법과 페이스트의 비증발 수량을 통해 평가하였다. 또한 HVFA 모르타르 시편을 이용하여 연령에 따른 압축강도를 측정하였다. 실험결과 FA의 치환율이 증가할수록 시멘트의 수화도는 증가하나 FA의 반응성은 감소하는 것으로 나타났다.

Keywords

Acknowledgement

본 연구는 국토교통부/국토교통과학기술진흥원의 지원으로 수행되었음(과제번호RS-2021-KA163949).

References

  1. Liu, J., Qiu, Q. W., Chen, X. C., Wang, X. D., Xing, F., Han, N. X., He,Y. J. (2016) , Degradation of fly ash concrete under the coupled effect of carbonation and chloride aerosol ingress, Corrosion Science, 112, 364-372. https://doi.org/10.1016/j.corsci.2016.08.004
  2. Liu, J., Qiu, Q. W., Xing, F., Pan, D. (2014) , Permeation properties and pore structure of surface layer of fly ash concrete, Materials, 7(6), 4282-4296. https://doi.org/10.3390/ma7064282
  3. Jin, Z. Q., Sun, W., Zhang, Y. S., Jiang, J. Y., Lai, J. Z. (2007), Interaction between sulfate and chloride solution attack of concretes with and without fly ash, Cement and Concrete Research, 37(8), 1223-1232. https://doi.org/10.1016/j.cemconres.2007.02.016
  4. Metha, P. K. (2004), High-performance, high-volume fly ash concrete for sustainable development, Proceedings of the International Workshop on Sustainable Development and Concrete Technology, Beijing, 3-14.
  5. Berry, E. E., Hemmings, R. T., Zhang, M. H., Cornelious, B. J., Golden, D. M. (1994), Hydration in high-volume fly ash binders, ACI Mater J, 91(4), 382-389.
  6. Moon, G. D., Oh, S., Choi, Y. C. (2016), Effects of the physicochemical properties of fly ash on the compressive strength of high-volume fly ash mortar, Construction and Building Materials, 124, 1072-1080. https://doi.org/10.1016/j.conbuildmat.2016.08.148
  7. Lam, L,. Wong, Y. L., Poon, C. S. (2000), Degree of hydration and gel/space ratio of high volume fly ash/cement systems, Cement and Concrete Research, 30(5), 747-756. https://doi.org/10.1016/S0008-8846(00)00213-1
  8. Berrey, E. E., Hemmings, R. T., Cornelius, B. J. (1990), Mechanisms of hydration reaction in high volume fly ash cements and mortars, Cement and Concrete Composites, 12(4), 253-261. https://doi.org/10.1016/0958-9465(90)90004-H
  9. Zeng, Q., Li, K., Fen-Chong, T., Dangla, P. (2012), Pore structure characterization of cement pastes blended with high volume fly-ash, Cement and Concrete Composites, 42(1), 194-204.
  10. Zhao, H., Qin, X., Liu, J., Zhou, L., Tian, Q., Wang, P. (2018), Pore structure characterization of early-age cement pastes blended with high-volume fly ash, Construction and Building Materials, 189, 934-946. https://doi.org/10.1016/j.conbuildmat.2018.09.023
  11. De Weerdt, K., Ben Haha, M,. Le Saout, G., Kjellsen, K. O., Justnes, H., Lothenbach, B. (2011), Hydration mechanisms of ternary Portland cements containing limestone powder and fly ash, Cement and Concrete Research, 41(3), 279-291. https://doi.org/10.1016/j.cemconres.2010.11.014
  12. Baert, G., Hoste, S., De Schutter, G., De Belie, N. (2008), Reactivity of fly ash in cement paste studied by means of thermogravimetry and isothermal calorimetry, Journal of Thermal Analysis and Calorimetry, 94(2), 485-492. https://doi.org/10.1007/s10973-007-8787-z
  13. Lothenbach, B., Scrivener, K., Hooton, R. D. (2011), Supplementary cementitious materials, Cement and Concrete Research, 41(12), 1244-1256. https://doi.org/10.1016/j.cemconres.2010.12.001
  14. Yilmaz, B., Olgun, A. (2008), Studies on cement and mortar containing low-calcium fly ash, limestone, and dolomitic limestone, Cement and Concrete Composites, 30(3), 194-201. https://doi.org/10.1016/j.cemconcomp.2007.07.002
  15. Luke, K., Glasser, F. P. (1988), Internal chemical evolution of the constitution of blended cements, Cement and Concrete Research, 18(4), 495-502. https://doi.org/10.1016/0008-8846(88)90042-7
  16. Ohsawa, S., Asaga, K., Goto, S., Daimon, M. (1985), Quantitative determination of fly ash in the hydrated fly ash-CaSO4ㆍ2H2O-Ca(OH)2 system, Cement and Concrete Research, 15, 357-366. https://doi.org/10.1016/0008-8846(85)90047-X
  17. Li, S., Roy, D. M., Kumer, A. (1985), Quantitative determination of pozzolanas in hydrated system of cement or Ca(OH)2 with fly ash or silica fume, Cement and Concrete Research, 15(6), 1079-1086. https://doi.org/10.1016/0008-8846(85)90100-0
  18. Gopalan, M. K. (1993), Nucleation and pozzolanic factors in strength development of Class F fly ash concrete, ACI Materials Journal, 90(2), 117-121.
  19. Feldman, R. F., Carette, G. G., Malhotra, V. M. (1990), Studies on of development of physical and mechanical properties of high-volume fly ash-cement pastes, Cement and Concrete Composites, 12(4), 245-251. https://doi.org/10.1016/0958-9465(90)90003-G
  20. Marsh, B. K., Day, R. L., Bonner, D. G. (1985), Pore structure characteristics affecting the permeability of cement paste containing fly ash, Cement and Concrete Research, 15(6), 1027-1038. https://doi.org/10.1016/0008-8846(85)90094-8
  21. Hinrichs, W., Odler, I. (1989), Investigation of the hydration of portland blastfurnace slag cement hydration kinetics, Advances in Cement Research, 2(5), 9-13. https://doi.org/10.1680/adcr.1989.2.5.9
  22. Papadakis, V. G. (1999), Effect of fly ash on Portland cement systems Part I. Low-calcium fly ash, Cement and Concrete Research, 29(11) , 1727-1736. https://doi.org/10.1016/S0008-8846(99)00153-2
  23. Zeng, Q., Li, K., Fen-Chong, T., Dangla, P. (2010), Surface fractal analysis of pore structure of high-volume fly-ash cement pastes, Applied Surface Science, 257(3), 762-768. https://doi.org/10.1016/j.apsusc.2010.07.061
  24. Zhao, H., Qin, X., Liu, J., Zhou, L., Tiane, Q., Wang, P. (2018), Pore structure characterization of early-age cement pastes blended with high-volume fly ash, Construction and Building Materials, 189, 934-946. https://doi.org/10.1016/j.conbuildmat.2018.09.023
  25. Yu, Ye, G. (2013), The pore structure of cement paste blended with fly ash, Construction and Building Materials, 45(7), 30-35. https://doi.org/10.1016/j.conbuildmat.2013.04.012
  26. Taylor, H. F. W. (1997), Cement Chemistry, second ed. Thomas Telford, London.
  27. Bhatty, J. I. (1986), Hydration versus strength in a portland cement developed from domestic mineral wastes-A comparative study, Thermochimica Acta, 106, 93-103. https://doi.org/10.1016/0040-6031(86)85120-6
  28. Bhatty, J. I., Reid K. J. (1985), Use of thermal analysis in the hydration studies of a type 1 portland cement produced from mineral tailings, Thermochimica Acta, 91, 95-105. https://doi.org/10.1016/0040-6031(85)85205-9
  29. Escalante-Garcia, J. I.. (2003), Nonevaporable water from neat OPC and replacement materials in composite cements hydrated at different temperatures, Cement Concrete Research, 33(11), 1883-1888. https://doi.org/10.1016/S0008-8846(03)00208-4
  30. Bentz, D. P., Sato, T., De la Varga, I., Weiss, W. J. (2012), Fine limestone additions to regulate setting in high volume fly ash mixtures, Cement & Concrete Composites, 34, 11-17. https://doi.org/10.1016/j.cemconcomp.2011.09.004
  31. Poon, C. S., Lam, L., Wong, Y. L. (2000), A study on high strength concrete prepared with large volumes of low calcium fly ash, Cement Concrete Research, 30, 447-455. https://doi.org/10.1016/S0008-8846(99)00271-9
  32. Chindaprasirt, P., Jaturapitakkul, C., Sinsiri, T. (2007), Effect of fly ash fineness on microstructure of blended cement paste, Construction and Building Materials, 21(7), 1534-1541. https://doi.org/10.1016/j.conbuildmat.2005.12.024
  33. Fraay, A. L. A., Bijen, J. M., Dehaan,Y. M. (1989), The reaction of fly ash in concrete - a critical examination, Cement and Concrete. Research, 19(2), 235-246. https://doi.org/10.1016/0008-8846(89)90088-4
  34. Rahhal, V., Talero, R. (2004), Influence of two different fly ashes on the hydration of Portland cements, Journal of Thermal Analysis and Calorimetry, 78(1), 191-205. https://doi.org/10.1023/B:JTAN.0000042167.46181.17
  35. Barbhuiya, S. A. Gbagbo, J. K., Russell, M. I., Basheerm, P. A. M. (2009), Properties of fly ash concrete modified with hydrated lime and silica fume, Construction and Building Materials, 23(10), 3233-3239. https://doi.org/10.1016/j.conbuildmat.2009.06.001
  36. Nayak, D. K., Abhilash, P. P., Singh, R., Kumar, R., Kumar, V. (2022), Fly ash for sustainable construction: A review of fly ash concrete and its beneficial use case studies, Cleaner Materials, 6, 100143. https://doi.org/10.1016/j.clema.2022.100143
  37. Mocharla, I.R., Selvam, R., Govindaraj, V., Muthu, M. (2022), Performance and life-cycle assessment of high-volume fly ash concrete mixes containing steel slag sand, Construction and Building Materials, 341, 127814. https://doi.org/10.1016/j.conbuildmat.2022.127814
  38. Wang, T., Ishida, T., Gu, R., Luan, Y. (2021), Experimental investigation of pozzolanic reaction and curing temperature-dependence of low-calcium fly ash in cement system and Ca-Si-Al element distribution of fly ash-blended cement paste, Construction and Building Materials, 267, 121012. https://doi.org/10.1016/j.conbuildmat.2020.121012