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http://dx.doi.org/10.6111/JKCGCT.2018.28.5.199

Study on the immersion test of geopolymers made by recycling of coal ash  

Bang, John J. (Department of Environmental, Earth & Geospatial Sciences, North Carolina Central University)
Kang, Seunggu (Department of Advanced Material Engineering, Kyonggi University)
Publication Information
Journal of the Korean Crystal Growth and Crystal Technology / v.28, no.5, 2018 , pp. 199-205 More about this Journal
Abstract
A geopolymer was produced from coal ash generated from an integrated gasification combined cycle (IGCC) plant and its water resistance was evaluated. For this purpose, the geopolymer specimens were immersed in water for 30 days to measure changes in microstructure and alkalinity of the immersion liquid. Particularly, the experiment was carried out with foaming status of the geopolymers and parameters of room temperature aging condition, and immersion time. The foamed geopolymer containing 0.1 wt% Si-sludge had pores with a diameter of 1 to 3 mm and exhibited excellent foamability. Also, the calcium-silicate-hydrate crystal phase appeared in the foamed geopolymer. In the geopolymer immersion experiment, the pH of the immersion liquid increased with time, because the un-reacted alkali activator remained was dissolved in the immersion liquid. From the pH change of the immersion liquid, it was found that geopolymer reaction in the foamed specimen was completed faster than the non-foamed specimen. Through this study, it was possible to successfully produce foamed and non-foamed geopolymers recycled from IGCC coal ash. Also the necessary data for the safe application of IGCC coal ash-based geopolymers to areas where water resistance is needed were established; for example, the process conditions for room temperature aging time, effect of foaming status, immersion time and so on.
Keywords
Coal ash; Recycling; Geopolymer; Immersion test; Water resistance;
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  • Reference
1 T. Bakharev, "Durability of geopolymer materials in sodium and magnesium sulfate solutions", Cem. Concr. Res. 35 (2005) 1233.   DOI
2 J. Davidovits, L. Buzzi, P. Rocher, D. Gimeno, C. Marini and S. Tocco, "Geopolymeric cement based on low cost geopolymer materials. Results from the european research project GEOCISTEM", Geopolymer'99 Proceeding (1999) 83.
3 A. Fernandez-Jimenez, I. Garcia-Lodeiro and A. Palomo, "Durability of alkali activated fly ash cementitious materials", J. Mater. Sci. 42 (2007) 3055.   DOI
4 A. Palomo, M. Blanco-Valera, M. Granizo, F. Puertas, T. Vazquez and M. Grutzeck, "Chemical stability of cementitious materials based on metakaolin", Cem. Concr. Res. 29 (1999) 997.   DOI
5 T. Silverstrim, H. Rostami, J. Clark and J. Martin, "Microstructure and properties of chemically activated fly ash concrete", Proc. 19th Int. Conf. Cem. Micro. (1997) 355.
6 T. Ueng, S. Lyu, H. Chu, H. Lee and T. Wang, "Adhesion at interface of geopolymer and cement mortar under compression: an experimental study", Constr. Build. Mater. 35 (2012) 204.   DOI
7 S. Yong, D. Feng, G. Lukey and J. Deventer, "Chemical characterisation of the steel-geopolymeric gel interface", Colloids Surf., A: Physicochem. Eng. Aspects 302 (2007) 411.   DOI
8 J. Provis, A. Palomo and C. Shi, "Advances in understanding alkali-activated materials", Cem. Concr. Res. 78 (2015) 110.   DOI
9 J. Davidovits, "Geopolymer chemistry and applications", Ins. Geopolymers, France, 2008.
10 F. Skvara, L. Kopecky, J. Nemecek and Z. Bittnar, "Microstructure of geopolymer materials based on fly ash", Ceram. Silik. 50 (2006) 208.
11 K. Komnitsas and D. Zaharaki, "Geopolymerisation: a review and prospects for the minerals industry", Miner. Eng. 20 (2007) 1261.   DOI
12 A. Nikolov, I. Rostovsky and H. Nugteren, "Geopolymer materials based on natural zeolite", Case Studies in Construction Materials 6 (2017) 198.   DOI
13 D. Satterthwaite, "Cities' contribution to global warming: notes on the allocation of greenhouse gas emissions", Environment & Urbanization 20 (2008) 539.   DOI
14 A. Bogomolov, B. Lepri, R. Larcher and F. Antonelli, "Energy consumption prediction using people dynamics derived from cellular network data", EPJ Data Sci. 5 (2016) 1.   DOI
15 O. Ohunakin, O. Leramo, O. Abidakun, M. Odunfa and O. Bafuwa, "Energy and cost analysis of cement production using the wet and dry processes in nigeria", Energy and Power Engineering 5 (2013) 537.   DOI
16 E. An, S. Cho, S. Lee, H. Miyauchi and G. Kim, "Compressive strength properties of geopolymer using power plant bottom ash and NaOH activator", Kor. J. Mater. Res. 22 (2012) 71.   DOI
17 J. Davidovits, "Geopolymers: Inorganic polymeric new materials", J. Therm. Anal. 37 (1991) 1633.   DOI
18 J. Davidovits, "Global warming impacts on the cement and aggregate industries", World Resource Review 6 (1994) 263.