Optimization of Hybrid Microwave Curing Approach Based On the Performance of Metakaolin-Based Geopolymer Mortars

Öz

Geopolymer binders have been highlighted due to their low carbon emission during production and processing. While metakaolin and F-type fly ash are commonly used as raw materials for aluminosilicate-based geopolymers, the long heat-curing requirements for hardening and strength development still pose challenges. This paper investigates the possible use of a hybrid microwave curing technique to design a set-on-demand approach to reduce the duration of heat curing in metakaolin-based geopolymer. The experimental design was established for samples with three different molar ratios (MR; 1.3,1.5, and 1.7) containing metakaolin, fly ash, and silica fume. Samples were subjected to 3 different curing regimes: oven curing, microwave (MW) curing, and hybrid curing (a combination of optimized microwave and oven curing). The performance evaluation was based on compressive strength, dimensional stability, and alkali leaching (efflorescence). Implementing only MW curing resulted in a significant decrease in compressive strength compared to their counterpart oven-cured samples. The reduction of compressive strength was more pronounced at lower molar ratios. The design of a hybrid curing approach where a portion of oven curing was replaced by MW resulted in a higher strength development than those only cured with MW. Similarly, the efficiency of hybrid curing was more pronounced in samples having MR of 1.5 and 1.7. Using MW curing in the geopolymer binders did not affect the alkali leaching; however, it increased the material’s drying shrinkage. Results showed that replacing a portion of oven curing with microwave curing in a hybrid approach can increase the operation speed and the hardening rate without significantly decreasing compressive strength.

Anahtar Kelimeler

• Geopolymer
• metakaolin
• microwave curing
• strength
• shrinkage

Kaynakça

1. K. Chen, Q. Liu, B. Chen, S. Zhang, L. Ferrara, W. Li, Effect of raw materials on the performance of 3D printing geopolymer: A review, Journal of Building Engineering 84 (2024) 108501. https://doi.org/10.1016/j.jobe.2024.108501.
2. Y.H.M. Amran, R. Alyousef, H. Alabduljabbar, M. El-Zeadani, Clean production and properties of geopolymer concrete; A review, J Clean Prod 251 (2020) 119679. https://doi.org/10.1016/j.jclepro.2019.119679.
3. N. Akhtar, T. Ahmad, D. Husain, A. Majdi, M.T. Alam, N. Husain, A.K.S. Wayal, Ecological footprint and economic assessment of conventional and geopolymer concrete for sustainable construction, J Clean Prod 380 (2022) 134910. https://doi.org/10.1016/j.jclepro.2022.134910.
4. B. Zhang, Durability of low-carbon geopolymer concrete: A critical review, Sustainable Materials and Technologies 40 (2024) e00882. https://doi.org/10.1016/j.susmat.2024.e00882.
5. P. Zhang, X. Han, S. Hu, J. Wang, T. Wang, High-temperature behavior of polyvinyl alcohol fiber-reinforced metakaolin/fly ash-based geopolymer mortar, Compos B Eng 244 (2022) 110171. https://doi.org/10.1016/j.compositesb.2022.110171.
6. W. Tu, M. Zhang, Behaviour of alkali-activated concrete at elevated temperatures: A critical review, Cem Concr Compos 138 (2023) 104961. https://doi.org/10.1016/j.cemconcomp.2023.104961.
7. M.C.G. Juenger, F. Winnefeld, J.L. Provis, J.H. Ideker, Advances in alternative cementitious binders, Cem Concr Res 41 (2011) 1232–1243. https://doi.org/10.1016/j.cemconres.2010.11.012.
8. K. Sankar, A. Sutrisno, W.M. Kriven, Slag-fly ash and slag-metakaolin binders: Part II—Properties of precursors and NMR study of poorly ordered phases, Journal of the American Ceramic Society 102 (2019) 3204–3227. https://doi.org/10.1111/jace.16224.

9. K. Sankar, P. Stynoski, G.K. Al-Chaar, W.M. Kriven, Sodium silicate activated slag-fly ash binders: Part I – Processing, microstructure, and mechanical properties, Journal of the American Ceramic Society 101 (2018) 2228–2244. https://doi.org/10.1111/jace.15391.
10. K. Sankar, P. Stynoski, W.M. Kriven, Sodium silicate activated slag-fly ash binders: Part III—Composition of soft gel and calorimetry, Journal of the American Ceramic Society 102 (2019) 3175–3190. https://doi.org/10.1111/jace.16219.
11. R. Bajpai, K. Choudhary, A. Srivastava, K.S. Sangwan, M. Singh, Environmental impact assessment of fly ash and silica fume based geopolymer concrete, J Clean Prod 254 (2020) 120147. https://doi.org/10.1016/j.jclepro.2020.120147.
12. A. Graytee, J.G. Sanjayan, A. Nazari, Development of a high strength fly ash-based geopolymer in short time by using microwave curing, Ceram Int 44 (2018) 8216–8222. https://doi.org/10.1016/j.ceramint.2018.02.001.
13. F. Puertas, S. Martı́nez-Ramı́rez, S. Alonso, T. Vázquez, Alkali-activated fly ash/slag cements, Cem Concr Res 30 (2000) 1625–1632. https://doi.org/10.1016/S0008-8846(00)00298-2.
14. P. Chindaprasirt, U. Rattanasak, S. Taebuanhuad, Role of microwave radiation in curing the fly ash geopolymer, Advanced Powder Technology 24 (2013) 703–707. https://doi.org/10.1016/j.apt.2012.12.005.
15. R. Prommas, T. Rungsakthaweekul, Effect of Microwave Curing Conditions on High Strength Concrete Properties, Energy Procedia 56 (2014) 26–34. https://doi.org/10.1016/j.egypro.2014.07.128.
16. M. Nadeem, E. Ul Haq, F. Ahmed, M. Asif Rafiq, G. Hameed Awan, M. Zain-ul-Abdein, Effect of microwave curing on the construction properties of natural soil based geopolymer foam, Constr Build Mater 230 (2020). https://doi.org/10.1016/j.conbuildmat.2019.117074.
17. J. Tan, J. Cai, L. Huang, Q. Yang, M. Mao, J. Li, Feasibility of using microwave curing to enhance the compressive strength of mixed recycled aggregate powder based geopolymer, Constr Build Mater 262 (2020). https://doi.org/10.1016/j.conbuildmat.2020.120897.
18. E.T. Thostenson, T.W. Chou, Microwave processing: fundamentals and applications, Compos. Part A: Appl. Sci. Manuf. 30 (1999) 1055–1070.
19. J. Somaratna, D. Ravikumar, N. Neithalath, Response of alkali activated fly ash mortars to microwave curing, Cem Concr Res 40 (2010) 1688–1696. https://doi.org/10.1016/j.cemconres.2010.08.010.
20. S. Das, A.K. Mukhopadhyay, S. Datta, D. Basu, Prospects of microwave processing: An overview, 2009.
21. Y. Sun, P. Zhang, J. Hu, B. Liu, J. Yang, S. Liang, K. Xiao, H. Hou, A review on microwave irradiation to the properties of geopolymers: Mechanisms and challenges, Constr Build Mater 294 (2021) 123491. https://doi.org/10.1016/j.conbuildmat.2021.123491.
22. Z. Dong, H. Ma, W. Feng, Y. Nie, H. Shi, Achieving superior high-strength geopolymer via the synergistic effect of traditional oven curing and microwave curing, Constr Build Mater 357 (2022) 129406. https://doi.org/10.1016/j.conbuildmat.2022.129406.
23. A.A. Shubbar, M. Sadique, P. Kot, W. Atherton, Future of clay-based construction materials – A review, Constr Build Mater 210 (2019) 172–187. https://doi.org/10.1016/j.conbuildmat.2019.03.206.
24. E.T. Thostenson, T.-W. Chou, Microwave processing: fundamentals and applications, Compos Part A Appl Sci Manuf 30 (1999) 1055–1071. https://doi.org/10.1016/S1359-835X(99)00020-2.
25. S. Muthukrishnan, S. Ramakrishnan, J. Sanjayan, Effect of microwave heating on interlayer bonding and buildability of geopolymer 3D concrete printing, Constr Build Mater 265 (2020) 120786. https://doi.org/10.1016/j.conbuildmat.2020.120786.
26. A. Noushini, A. Castel, The effect of heat-curing on transport properties of low-calcium fly ash-based geopolymer concrete, Constr Build Mater 112 (2016) 464–477. https://doi.org/10.1016/j.conbuildmat.2016.02.210.
27. A. Noushini, F. Aslani, A. Castel, R.I. Gilbert, B. Uy, S. Foster, Compressive stress-strain model for low-calcium fly ash-based geopolymer and heat-cured Portland cement concrete, Cem Concr Compos 73 (2016) 136–146. https://doi.org/10.1016/j.cemconcomp.2016.07.004.
28. ASTM International, ASTM C305-14 Standard Practice for Mechanical Mixing of Hydraulic Cement Pastes andMortars of Plastic Consistency, West Conshohocken, 2014. https://doi.org/10.1520/C0305-14.2.
29. B. Panda, C. Unluer, M.J. Tan, Investigation of the rheology and strength of geopolymer mixtures for extrusion-based 3D printing, Cem Concr Compos 94 (2018) 307–314. https://doi.org/10.1016/j.cemconcomp.2018.10.002.
30. European Standarts, EN 196-1: Methods of testing cement - Part 1: Determination of strength, 2016.
31. ASTM, ASTM C 596-18 Standard Test Method for Drying Shrinkage of Mortar Containing Hydraulic Cement, West Conshohocken, PA, USA, 2018.
32. B. Li, A. Gao, Y. Li, H. Xiao, N. Chen, D. Xia, S. Wang, C. Li, Effect of silica fume content on the mechanical strengths, compressive stress–strain behavior and microstructures of geopolymeric recycled aggregate concrete, Constr Build Mater 384 (2023) 131417. https://doi.org/10.1016/j.conbuildmat.2023.131417.
33. Q. Wan, F. Rao, S. Song, R.E. García, R.M. Estrella, C.L. Patiño, Y. Zhang, Geopolymerization reaction, microstructure and simulation of metakaolin-based geopolymers at extended Si/Al ratios, Cem Concr Compos 79 (2017) 45–52. https://doi.org/10.1016/j.cemconcomp.2017.01.014.
34. M.S. Muñiz-Villarreal, 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, V. Amigó-Borrás, The effect of temperature on the geopolymerization process of a metakaolin-based geopolymer, Mater Lett 65 (2011) 995–998. https://doi.org/10.1016/j.matlet.2010.12.049.
35. M. Mastali, P. Kinnunen, A. Dalvand, R. Mohammadi Firouz, M. Illikainen, Drying shrinkage in alkali-activated binders – A critical review, Constr Build Mater 190 (2018) 533–550. https://doi.org/10.1016/j.conbuildmat.2018.09.125.
36. P. Duan, C. Yan, W. Zhou, W. Luo, Thermal Behavior of Portland Cement and Fly Ash–Metakaolin-Based Geopolymer Cement Pastes, Arab J Sci Eng 40 (2015) 2261–2269. https://doi.org/10.1007/s13369-015-1748-0.
37. I. Khan, T. Xu, A. Castel, R.I. Gilbert, M. Babaee, Risk of early age cracking in geopolymer concrete due to restrained shrinkage, Constr Build Mater 229 (2019). https://doi.org/10.1016/j.conbuildmat.2019.116840.
38. S. Wallah, Creep behaviour of fly ash-based geopolymer concrete, , Civ. Eng. Dimens. 12 (2) (2010) 73–78 12 (2010) 73–78.
39. T. Yang, H. Zhu, Z. Zhang, Influence of fly ash on the pore structure and shrinkage characteristics of metakaolin-based geopolymer pastes and mortars, Constr Build Mater 153 (2017) 284–293. https://doi.org/10.1016/j.conbuildmat.2017.05.067.
40. F. Škvára, S. Pavlasová, L. Kopecký, L. Myšková, L. Alberovská, 3rd International Symposium on Non-traditional Cement and Concrete, in: High Temperature Properties of Fly Ash-Based Geopolymers, 2008: pp. 741–750.
41. Z. Zhang, J.L. Provis, A. Reid, H. Wang, Fly ash-based geopolymers: The relationship between composition, pore structure and efflorescence, Cem Concr Res 64 (2014) 30–41. https://doi.org/10.1016/j.cemconres.2014.06.004.
42. P. Duxson, G.C. Lukey, F. Separovic, J.S.J. van Deventer, Effect of Alkali Cations on Aluminum Incorporation in Geopolymeric Gels, Ind Eng Chem Res 44 (2005) 832–839. https://doi.org/10.1021/ie0494216.
43. M. Criado, A. Fernández-Jiménez, A. Palomo, Alkali activation of fly ash: Effect of the SiO2/Na2O ratio. Part I: FTIR study, Microporous and Mesoporous Materials 106 (2007) 180–191. https://doi.org/10.1016/j.micromeso.2007.02.055.
44. N. Granizo, A. Palomo, A. Fernandez-Jiménez, Effect of temperature and alkaline concentration on metakaolin leaching kinetics, Ceram Int 40 (2014) 8975–8985. https://doi.org/10.1016/j.ceramint.2014.02.071.
45. E. Najafi Kani, A. Allahverdi, J.L. Provis, Efflorescence control in geopolymer binders based on natural pozzolan, Cem Concr Compos 34 (2012) 25–33. https://doi.org/10.1016/j.cemconcomp.2011.07.007.