Early Hydration Kinetics and Microstructure Development of MgO-Activated Slag at Room Temperature
Publication: Journal of Materials in Civil Engineering
Volume 35, Issue 1
Abstract
In this paper, active MgO was used as the alkali activator, and the early hydration kinetics and microstructure development of MgO-activated slag were explored by means of the hydration heat test, X-ray diffraction (XRD), thermogravimetry (TG-DTG), Fourier transform infrared spectroscopy (FT-IR), mercury intrusion porosimetry (MIP), and scanning electron microscopy–energy dispersive spectrometry (SEM-EDS). Three types of MgO were selected based on reaction time (). The other two variables in this study include MgO content and curing age. The research results show that S-MgO is more suitable as an alkali activator and the total hydration heat of S-MgO-activated slag is much lower. The second exothermic peak is more obvious with the increase of MgO content. The main early hydration products of S-MgO-activated slag were a hydrotalcite-like phase, C-S-H gels, and C-A-S-H gels; the early main hydration product of R-MgO-activated slag was brucite. With the increase of MgO content, the total porosity decreases, i.e., the total porosity of the S-MgO specimen is the smallest, followed by the M-MgO specimen, and the total porosity of the R-MgO specimen is the largest. With the increase of S-MgO content, the processes of crystal nucleation and crystal growth are accelerated. When the S-MgO content is 20% by weight, the phase boundary reaction process and diffusion process of the MgO-activated slag system accelerates, which is more conducive to the diffusion, recombination, and precipitation of hydration products. This study provides an experimental and theoretical basis for the use of green alkali activator.
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Data Availability Statement
All data, models, and code generated or used during the study appear in the published article.
Acknowledgments
This research was funded by the High-level Innovative Talents Program of Hebei University (521100221036) and Science and Technology Project of Hebei Education Department (QN2022067) . The corresponding author acknowledges the financial support provided by the National Natural Science Foundation of China (51978025).
References
Abdalqader, A., F. Jin, and A. Al-Tabbaa. 2019. “Performance of magnesia-modified sodium carbonate-activated slag/fly ash concrete.” Cem. Concr. Compos. 103 (Oct): 160–174. https://doi.org/10.1016/j.cemconcomp.2019.05.007.
Atiş, C. D., C. Bilim, Ö. Çelik, and O. Karahan. 2009. “Influence of activator on the strength and drying shrinkage of alkali-activated slag mortar.” Constr. Build. Mater. 23 (1): 548–555. https://doi.org/10.1016/j.conbuildmat.2007.10.011.
Bahafid, S., S. Ghabezloo, P. Faure, M. Duc, and J. Sulem. 2018. “Effect of the hydration temperature on the pore structure of cement paste: Experimental investigation and micromechanical modelling.” Cem. Concr. Res. 111 (Sep): 1–14. https://doi.org/10.1016/j.cemconres.2018.06.014.
Ben Haha, M., B. Lothenbach, G. Le Saout, and F. Winnefeld. 2011. “Influence of slag chemistry on the hydration of alkali-activated blast furnace slag—Part I: Effect of MgO.” Cem. Concr. Res. 41 (9): 955–963. https://doi.org/10.1016/j.cemconres.2011.05.002.
Bernal, S. A., R. S. Nicolas, R. J. Myers, R. M. de Gutiérrez, F. Puertas, J. S. J. van Deventer, and J. L. Provis. 2014. “MgO content of slag controls phase evolution and structural changes induced by accelerated carbonation in alkali-activated binders.” Cem. Concr. Res. 57 (Mar): 33–43. https://doi.org/10.1016/j.cemconres.2013.12.003.
Cao, F. Z., and P. Y. Yan. 2019. “The influence of the hydration procedure of MgO expansive agent on the expansive behavior of shrinkage-compensating mortar.” Constr. Build. Mater. 202 (Mar): 162–168. https://doi.org/10.1016/j.conbuildmat.2019.01.016.
Collins, F., and J. G. Sanjayan. 2000. “Effect of pore size distribution on drying shrinking of alkali-activated slag concrete.” Cem. Concr. Res. 30 (9): 1401–1406. https://doi.org/10.1016/S0008-8846(00)00327-6.
Han, F., and Z. Zhang. 2018. “Properties of 5-year-old concrete containing steel slag powder.” Powder Technol. 334 (Jul): 27–35. https://doi.org/10.1016/j.powtec.2018.04.054.
Han, F. H., Q. Wang, and M. T. Liu. 2016. “Early hydration properties of composite binder containing limestone powder with different finenesses.” J. Therm. Anal. Calorim. 123 (2): 1141–1151. https://doi.org/10.1007/s10973-015-5088-9.
Hay, R., N. T. Dung, A. Lesimple, C. Unluer, and K. Celik. 2021. “Mechanical and microstructural changes in reactive magnesium oxide cement-based concrete mixes subjected to high temperatures.” Cem. Concr. Compos. 118 (Apr): 103955. https://doi.org/10.1016/j.cemconcomp.2021.103955.
Hobson, A. J., D. I. Stewart, R. J. G. Mortimer, W. M. Mayes, M. Rogerson, and I. T. Burke. 2017. “Mechanism of vanadium leaching during surface weathering of basic oxygen furnace steel slag blocks: A microfocus X-ray absorption spectroscopy and electron microscopy study.” Environ. Sci. Technol. 51 (14): 7823–7830. https://doi.org/10.1021/acs.est.7b00874.
Ibrahim, M., and M. Maslehuddin. 2021. “An overview of factors influencing the properties of alkali-activated binders.” J. Cleaner Prod. 286 (Mar): 124971. https://doi.org/10.1016/j.jclepro.2020.124972.
Jansen, D., F. Goetz-Neunhoeffer, B. Lothenbach, and J. Neubauer. 2012. “The early hydration of ordinary portland cement (OPC): An approach comparing measured heat flow with calculated heat flow from QXRD.” Cem. Concr. Res. 42 (1): 134–138. https://doi.org/10.1016/j.cemconres.2011.09.001.
Jin, F., and A. Al-Tabbaa. 2014. “Characterisation of different commercial reactive magnesia.” Adv. Cem. Res. 26 (2): 101–113. https://doi.org/10.1680/adcr.13.00004.
Jin, F., K. Gu, and A. Al-Tabbaa. 2014. “Strength and drying shrinkage of reactive MgO modified alkali-activated slag paste.” Constr. Build. Mater. 51 (Jan): 395–404. https://doi.org/10.1016/j.conbuildmat.2013.10.081.
Jin, F., K. Gu, and A. Al-Tabbaa. 2015. “Strength and hydration properties of reactive MgO-activated ground granulated blastfurnace slag paste.” Cem. Concr. Compos. 57 (Mar): 8–16. https://doi.org/10.1016/j.cemconcomp.2014.10.007.
Kaja, A. M., A. Delsing, S. R. van der Laan, H. J. H. Brouwers, and Q. L. Yu. 2021. “Effects of carbonation on the retention of heavy metals in chemically activated BOF slag pastes.” Cem. Concr. Res. 148 (Oct): 106534. https://doi.org/10.1016/j.cemconres.2021.106534.
Kielė, A., D. Vaičiukynienė, G. Tamošaitis, and R. Bistrickaitė. 2020. “Thermal properties of alkali activated slag plaster for wooden structures.” Sci. Rep. 10 (1): 1–9. https://doi.org/10.1038/s41598-020-57515-8.
Li, Y., Y. C. Guo, Z. H. Lyu, and X. Wei. 2021. “Investigation of the effect of waterborne epoxy resins on the hydration kinetics and performance of cement blends.” Constr. Build. Mater. 301 (Sep): 124045. https://doi.org/10.1016/j.conbuildmat.2021.124045.
Liu, L., P. Yang, C. C. Qi, B. Zhang, L. G. Guo, and K. I. Song. 2019. “An experimental study on the early-age hydration kinetics of cement paste backfill.” Constr. Build. Mater. 212 (Jul): 283–294. https://doi.org/10.1016/j.conbuildmat.2019.03.322.
Lu, B., W. P. Zhu, Y. W. Weng, Z. X. Liu, E. H. Yang, K. F. Leong, M. J. Tan, T. N. Wong, and S. Z. Qian. 2021. “Study of MgO-activated slag as a cementless material for sustainable spray-based 3D printing.” J. Cleaner Prod. 123 (Jun): 104200. https://doi.org/10.1016/j.jclepro.2020.120671.
Ma, H. Q., S. C. Zhang, and J. J. Feng. 2022. “Physicochemical properties of MgO-silica fume cementitious materials exposed to high temperatures.” J. Build. Eng. 50 (Jun): 104124. https://doi.org/10.1016/j.jobe.2022.104124.
Ma, H. Q., H. G. Zhu, C. Wu, H. Y. Chen, J. W. Sun, and J. Y. Liu. 2020. “Study on compressive strength and durability of alkali-activated coal gangue-slag concrete and its mechanism.” Powder Technol. 368 (May): 112–124. https://doi.org/10.1016/j.powtec.2020.04.054.
Ma, H. Q., H. G. Zhu, C. Yi, J. C. Fan, H. Y. Chen, X. N. Xu, and T. Wang. 2019. “Preparation and reaction mechanism characterization of alkali-activated coal gangue-slag materials.” Materials 12 (Jul): 2250. https://doi.org/10.3390/ma12142250.
Mo, L. W., and D. K. Panesar. 2013. “Accelerated carbonation—A potential approach to sequester in cement paste containing slag and reactive MgO.” Cem. Concr. Compos. 43 (Oct): 69–77. https://doi.org/10.1016/j.cemconcomp.2013.07.001.
Mo, L. W., F. Zhang, M. Deng, and D. K. Panesar. 2016. “Effectiveness of using pressure to enhance the carbonation of portland cement-fly ash-MgO mortars.” Cem. Concr. Compos. 70 (Jul): 78–85. https://doi.org/10.1016/j.cemconcomp.2016.03.013.
Osio-Norgaard, J., A. N. Aday, X. Chen, S. L. Williams, J. P. Gevaudan, and W. V. Srubar III. 2021. “Silica-modifying chemical admixtures for directed zeolitization of metakaolin-based alkali-activated materials.” Cem. Concr. Res. 142 (Apr): 106348. https://doi.org/10.1016/j.cemconres.2020.106348.
Pan, Y., C. Wu, and X. Huang. 2017. “Long-term durability testing on the MgO-activated slag cured in brine.” Constr. Build. Mater. 144 (Jul): 271–278. https://doi.org/10.1016/j.conbuildmat.2017.03.192.
Pang, X. Y., L. J. Sun, F. Sun, G. Zhang, S. H. Guo, and Y. H. Bu. 2021. “Cement hydration kinetics study in the temperature range from 15°C to 95°C.” Cem. Concr. Res. 148 (Oct): 106552. https://doi.org/10.1016/j.cemconres.2021.106552.
Park, S., H. M. Park, H. N. Yoon, J. Seo, C. M. Yang, J. L. Provis, and B. Yang. 2020. “Hydration kinetics and products of MgO-activated blast furnace slag.” Constr. Build. Mater. 249 (Jul): 118700. https://doi.org/10.1016/j.conbuildmat.2020.118700.
Phair, J., and J. van Deventer. 2002. “Effect of the silicate activator pH on the microstructural characteristics of waste-based geopolymers.” Int. J. Miner. Process. 66 (1–4): 121–143. https://doi.org/10.1016/S0301-7516(02)00013-3.
Repette, W., A. A. M. Neto, and M. A. Cincotto. 2008. “Drying and autogenous shrinkage of pastes and mortars with activated slag cement.” Cem. Concr. Res. 38 (4): 565–574. https://doi.org/10.1016/j.cemconres.2007.11.002.
Seo, J., H. N. Yoon, S. Kim, Z. Wang, T. Kil, and H. K. Lee. 2021. “Characterization of reactive MgO-modified calcium sulfoaluminate cements upon carbonation.” Cem. Concr. Res. 146 (Aug): 106484. https://doi.org/10.1016/j.cemconres.2021.106484.
Shi, C., A. F. Jiménez, and A. Palomo. 2011. “New cements for the 21th century: The pursuit of an alternative to portland cement.” Cem. Concr. Res. 41 (7): 750–763. https://doi.org/10.1016/j.cemconres.2011.03.016.
Tafesse, M., H. K. Lee, A. S. Alemu, H. K. Kim, and S. Pyo. 2020. “On the expansive cracking of a cement matrix containing atomized basic oxygen furnace slag with a metallic iron.” Constr. Build. Mater. 264 (Dec): 119806. https://doi.org/10.1016/j.conbuildmat.2020.119806.
Theiss, F. L., G. A. Ayoko, and R. L. Frost. 2013. “Thermogravimetric analysis of selected layered double hydroxides.” J. Therm. Anal. Calorim. 112 (2): 649–657. https://doi.org/10.1007/s10973-012-2584-z.
Trittschack, R., B. Grobety, and P. Brodard. 2014. “Kinetics of the chrysotile and brucite dihydroxylation reaction: A combined non-isothermal/isothermal thermogravimetric analysis and high-temperature X-ray powder diffraction study.” Phys. Chem. Miner. 41 (3): 197–214. https://doi.org/10.1007/s00269-013-0638-9.
Yang, K. R., and W. E. Claire. 2020. “Multiscale pore structure determination of cement paste via simulation and experiment: The case of alkali-activated metakaolin.” Cem. Concr. Res. 137 (Nov): 106212. https://doi.org/10.1016/j.cemconres.2020.106212.
Ye, H. L., C. Cartwright, F. Rajabipour, and A. Radlin’ska. 2017. “Understanding the drying shrinkage performance of alkali-activated slag mortars.” Cem. Concr. Compos. 76 (Feb): 13–24. https://doi.org/10.1016/j.cemconcomp.2016.11.010.
Yi, C., H. Q. Ma, H. Y. Chen, J. X. Wang, J. Shi, Z. H. Li, and M. K. Yu. 2018. “Preparation and characterization of coal gangue geopolymers.” Constr. Build. Mater. 187 (Oct): 318–326. https://doi.org/10.1016/j.conbuildmat.2018.07.220.
Yi, Y. L., M. Liska, A. Al-Tabbaa, R. K. Dhir, and K. Paine. 2014. “Properties and microstructure of GGBS-MgO pastes.” Adv. Cem. Res. 26 (2): 114–122. https://doi.org/10.1680/adcr.13.00005.
Yu, P., R. J. Kirkpatrick, B. Poe, P. F. McMillan, and X. D. Cong. 1999. “Structure of calcium silicate hydrate (C-S-H): Near-, mid-, and far-infrared spectroscopy.” J. Am. Ceram. Soc. 82 (3): 742–748. https://doi.org/10.1111/j.1151-2916.1999.tb01826.x.
Zhang, Y. S., H. R. Jiang, Y. C. Du, C. Q. Wang, and H. Wang. 2021. “Surface alcoholysis induced by alkali-activation ethanol: A novel scheme for binary flotation of polyethylene terephthalate from other plastics.” J. Cleaner Prod. 314 (Sep): 128096. https://doi.org/10.1016/j.jclepro.2021.128096.
Zheng, J. R., X. X. Sun, L. J. Guo, S. M. Zhang, and J. Y. Chen. 2019. “Strength and hydration products of cemented paste backfill from sulphide-rich tailings using reactive MgO-activated slag as a binder.” Constr. Build. Mater. 203 (Apr): 111–119. https://doi.org/10.1016/j.conbuildmat.2019.01.047.
Zhou, L. F., M. F. Gou, and X. M. Guan. 2021. “Hydration kinetics of cement-calcined activated bauxite tailings composite binder.” Constr. Build. Mater. 301 (Sep): 124296. https://doi.org/10.1016/j.conbuildmat.2021.124296.
Zhuang, S. Y., and Q. Wang. 2021. “Inhibition mechanisms of steel slag on the early-age hydration of cement.” Cem. Concr. Res. 140 (Feb): 106283. https://doi.org/10.1016/j.cemconres.2020.106283.
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Published In
Journal of Materials in Civil Engineering
Volume 35 • Issue 1 • January 2023
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© 2022 American Society of Civil Engineers.
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Received: Jan 5, 2022
Accepted: May 4, 2022
Published online: Oct 26, 2022
Published in print: Jan 1, 2023
Discussion open until: Mar 26, 2023
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