Synthesis and Reaction Mechanism of an Alkali-Activated Metakaolin-Slag Composite System at Room Temperature
Publication: Journal of Materials in Civil Engineering
Volume 31, Issue 1
Abstract
Synthesis of geopolymer using metakaolin (MK) usually requires a relatively high curing temperature, which limits the application of MK-based geopolymers in the practice of civil engineering. With the goal of developing a cementitious composite that can be cured at room temperature, in the present study, ground granulated blast furnace slag powder was incorporated into MK for the synthesis of a geopolymer. With the aid of compressive strength tests, X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, and scanning electron microscopy (SEM), the influence of slag’s impact on the consistency, gelling time, and mechanical properties of the gelling system, as well as the reaction mechanism of the composite system, were investigated. The results showed that the incorporation of slag into MK improved the consistency of the slurry and shortened the setting time. A high-strength paste was synthesized successfully using the MK-slag composite system under ambient temperature curing. Results of XRD and FTIR analyses indicated that MK geopolymerization and slag hydration occurred simultaneously in the MK-slag composite system via alkali activation. The structure of hardened paste consists of both C-S-H-type and N-A-S-H-type gels. The activator module and the MK/slag mass ratio were the main factors affecting the strength of the synthesized products: when the slag replacement ratio was no more than 40%, the strength of the reaction products decreased with an increase of the activator module; when the slag replacement ratio reached or exceeded 60%, the strength of the reaction products increased with the increasing activator module.
Get full access to this article
View all available purchase options and get full access to this article.
Acknowledgments
This research was supported by the National Key Basic Research Program of China (973 Program) (Grant No. 2015CB057701), the National Natural Science Foundation of China (Grant Nos. 51578078 and 51878068), the Louisiana Board of Regents [Contract No. LEQSF(2017-20)-RD-B-02], and the Hunan Science Fund for Distinguished Young Scholars (Grant No. 2017JJ1027). The writers thank their colleagues and other personnel from the Changsha University of Science and Technology and the Louisiana State University for providing support for this project. This extensive investigation was carried out as a result of the input and involvement of many individuals to whom the writers express their sincere thanks and gratitude.
References
Bai, E. L., J. Y. Xu, H. Li, and T. Zhang. 2014. “Experimental study on setting and hardening characteristics of slag-fly ash cementitious material system added different modifier.” Bull. Chin. Ceram. Soc. 33 (12): 3250–3254. https://doi.org/10.16552/j.cnki.issn1001-1625.2014.12.050.
Chinese Standard. 1999. Method of testing cements-determination of strength. GB/T 17671. Beijing: National Standard of the People's Republic of China.
Chinese Standard. 2008. Ground granulated blast furnace slag used for cement and concrete. GB/T 18046. Beijing: National Standard of the People's Republic of China.
Chinese Standard. 2011. Test methods for water requirement of normal consistency, setting time and soundness of the portland cement. GB/T 1346. Beijing: National Standard of the People's Republic of China.
Davidovits, J. 1991. “Geopolymers: Inorganic polymeric new materials.” J. Therm. Anal. Calorim. 37 (8): 1633–1656. https://doi.org/10.1007/BF01912193.
Duxson, P., G. C. Lukey, F. Separovic, and J. S. J. Van Deventer. 2005. “Effect of alkali cations on aluminum incorporation in geopolymeric gels.” Ind. Eng. Chem. Res. 44 (4): 832–839. https://doi.org/10.1021/ie0494216.
Duxson, P., S. W. Mallicoat, G. C. Lukey, W. M. Kriven, and J. S. J. Van Deventer. 2007. “The effect of alkali and Si/Al ratio on the development of mechanical properties of metakaolin-based geopolymers.” Colloids Surf. A 292 (1): 8–20. https://doi.org/10.1016/j.colsurfa.2006.05.044.
He, P., M. Wang, S. Fu, D. C. Jia, S. Yan, J. K. Yuan, J. H. Xu, P. F. Wang, and Y. Zhou. 2016. “Effects of Si/Al ratio on the structure and properties of metakaolin based geopolymer.” Ceram. Int. 42 (13): 14416–14422. https://doi.org/10.1016/j.ceramint.2016.06.033.
Hou, X. K., Y. B. Dong, B. Xue, H. S. Li, H. Y. Yang, and J. S. Yuan. 2014. “Study on low heat steel slag and blast furnace slag portland cement (i): Cement performance with its proportion.” Bull. Chin. Ceram. Soc. 33 (10): 2451–2460. https://doi.org/10.16552/j.cnki.issn1001-1625.2014.10.016.
Jia, Y. H., M. F. Han, X. X. Meng, and Z. S. Xu. 2009. “Study on setting time of fly ash-based geopolymer.” Bull. Chin. Ceram. Soc. 28 (5): 893–899. https://doi.org/10.16552/j.cnki.issn1001-1625.2009.05.001.
Kuo, W. T., H. Y. Wang, and C. Y. Shu. 2014. “Engineering properties of cementless concrete produced from GGBFS and recycled desulfurization slag.” Constr. Build. Mater. 63: 189–196. https://doi.org/10.1016/j.conbuildmat.2014.04.017.
Li, X. G., C. Q. Duan, B. G. Ma, and J. Huang. 2013. “Research on polymer-modified metakaolin-based geopolymer material.” Concrete 12: 103–106.
Liu, S. F., Z. J. Li, and P. M. Wang. 2007. “Comparison of two methods for improving compressive strength of fly ash based geopolymers.” Mater. Rev. 21 (11): 141–143.
Mahieux, P. Y., J. E. Aubert, and G. Escadeillas. 2009. “Utilization of weathered basic oxygen furnace slag in the production of hydraulic road binders.” Constr. Build. Mater. 23 (2): 742–747. https://doi.org/10.1016/j.conbuildmat.2008.02.015.
Mo, B. H., H. Zhu, X. M. Cui, Y. He, and S. Y. Gong. 2014. “Effect of curing temperature on geopolymerization of metakaolin-based geopolymers.” Appl. Clay Sci. 99 (3): 144–148. https://doi.org/10.1016/j.clay.2014.06.024.
Muñiz-Villarreal, M. S., A. Manzano-Ramírez, S. Sampieri-Bulbarela, J. R. Gasca-Tirado, J. L. Reyes-Araiza, J. C. Rubio-Ávalos, J. J. Pérez-Bueno, L. M. Apatiga, A. Zaldivar-Cadena, and V. Amigó-Borrás. 2011. “The effect of temperature on the geopolymerization process of a metakaolin-based geopolymer.” Mater. Lett. 65 (6): 995–998. https://doi.org/10.1016/j.matlet.2010.12.049.
Nath, P., and P. K. Sarker. 2014. “Effect of GGBFS on setting, workability and early strength properties of fly ash geopolymer concrete cured in ambient condition.” Constr. Build. Mater. 66: 163–171. https://doi.org/10.1016/j.conbuildmat.2014.05.080.
Ozer, I., and S. Soyer-Uzun. 2015. “Relations between the structural characteristics and compressive strength in metakaolin based geopolymers with different molar Si/Al ratios.” Ceram. Int. 41 (8): 10192–10198. https://doi.org/10.1016/j.ceramint.2015.04.125.
Palomo, A., M. W. Grutzeck, and M. T. Blanco. 1999. “Alkali-activated fly ashes: A cement for the future.” Cem. Concr. Res. 29 (8): 1323–1329. https://doi.org/10.1016/S0008-8846(98)00243-9.
Pelletier, L., F. Winnefeld, and B. Lothenbach. 2010. “The ternary system portland cement–calcium sulphoaluminate clinker–anhydrite: Hydration mechanism and mortar properties.” Cem. Concr. Compos. 32 (7): 497–507. https://doi.org/10.1016/j.cemconcomp.2010.03.010.
Rovnaník, P. 2010. “Effect of curing temperature on the development of hard structure of metakaolin-based geopolymer.” Constr. Build. Mater. 24 (7): 1176–1183. https://doi.org/10.1016/j.conbuildmat.2009.12.023.
Sakulich, A. R., E. Anderson, C. L. Schauer, and M. W. Barsoum. 2010. “Influence of Si:Al ratio on the microstructural and mechanical properties of a fine-limestone aggregate alkali-activated slag concrete.” Mater. Struct. 43 (7): 1025–1035. https://doi.org/10.1617/s11527-009-9563-2.
Weng, L., and K. Sagoe-Crentsil. 2007. “Dissolution processes, hydrolysis and condensation reactions during geopolymer synthesis. Part I: Low Si/Al ratio systems.” J. Mater. Sci. 42 (9): 2997–3006. https://doi.org/10.1007/s10853-006-0820-2.
Winnefeld, F., and B. Lothenbach. 2010. “Hydration of calcium sulfoaluminate cements—Experimental findings and thermodynamic modelling.” Cem. Concr. Res. 40 (8): 1239–1247. https://doi.org/10.1016/j.cemconres.2009.08.014.
Yip, C. K., G. C. Lukey, J. L. Provis, and J. S. J. Van Deventer. 2008. “Effect of calcium silicate sources on geopolymerisation.” Cem. Concr. Res. 38 (4): 554–564. https://doi.org/10.1016/j.cemconres.2007.11.001.
Yip, C. K., G. C. Lukey, and J. S. J. Van Deventer. 2005. “The coexistence of geopolymeric gel and calcium silicate hydrate at the early stage of alkaline activation.” Cem. Concr. Res. 35 (9): 1688–1697. https://doi.org/10.1016/j.cemconres.2004.10.042.
Zhang, J. F., H. Ding, K. Dai, and C. Sun. 2007a. “Microstructure and properties of hydration products of slag-fly ash mixed cementitious materials.” J. Chin. Ceram. Soc. 35 (5): 633. https://doi.org/10.14062/j.issn.0454-5648.2007.05.021.
Zhang, Y. S., W. Sun, Q. L. Chen, and L. Chen. 2007b. “Synthesis and heavy metal immobilization behaviors of slag based geopolymer.” J. Hazard. Mater. 143 (1–2): 206–213. https://doi.org/10.1016/j.jhazmat.2006.09.033.
Zhu, H. J., X. Yao, Z. H. Zhang, S. D. Hua, and Y. Chen. 2009. “Effect of slag dosage on compressive strength and pore structure of metakaolin-based geopolymeric cement.” J. Nanjing Univ. Technol. (Nat. Sci. Ed.) 2: 1–4.
Information & Authors
Information
Published In
Journal of Materials in Civil Engineering
Volume 31 • Issue 1 • January 2019
Copyright
©2018 American Society of Civil Engineers.
History
Received: Jan 4, 2018
Accepted: Jul 6, 2018
Published online: Oct 26, 2018
Published in print: Jan 1, 2019
Discussion open until: Mar 26, 2019
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.