Optimization of alkali-activated fly ash-based geopolymer mortar: Influence of activator composition on strength and workability

Sathia Ramalingam; Vijayalakshmi Ramalingam; Aswin Sriram G

doi:10.62638/ZasMat1420

Authors

Sathia Ramalingam Department of Civil Engineering, Sri Venkateswara College of Engineering, Chennai, India Author https://orcid.org/0000-0002-0851-2145
Vijayalakshmi Ramalingam Department of Civil Engineering, Sri Sivasubramaniya Nadar College of Engineering, Kalavakkam, Chennai , India Author https://orcid.org/0000-0003-4678-2020
Dr Aswin Sriram G Department of Civil Engineering, Sri Sivasubramaniya Nadar College of Engineering, Kalavakkam, Chennai, India Author https://orcid.org/0000-0001-7416-8605

DOI:

https://doi.org/10.62638/ZasMat1420

Abstract

The effect of different combinations of alkali activator compositions, water content and mix proportions on rheology, mechanical properties and microstructure of fly ash-based geopolymer mortars are studied in this paper. Geopolymer mortars were synthesized at a sand-to-fly ash ratio of 2:1, sodium hydroxide (NaOH) molarity varied at 8M, 12M, 14M, 16M, and sodium silicate-to-NaOH ratios of 0·1–2·5. The water content was varied from 1-8% by weight of fly ash for the fixed solution-to-binder ratios of 0.4 and 0.5. Tests for flowability showed a workability between 120 to 140%. The compressive strength was determined at 3, 7, and 28 days. Maximum strength attained was 68 MPa at NaOH 16M and SS/NaOH ratio of 1.5. X-ray diffraction (XRD) analysis showed the formation of a zeolite (hydroxysodalite) phase at higher SS/NaOH ratios, resulting in higher strength. Increasing the ratio of H₂O and Na₂O more than 0.22 decreased strength due to porosity increase. The highest compressive strength was found at Na₂O/SiO₂ ratio of 0.15 to 0.17. The results define important activator ratios which help balance flowability and strength in geopolymer mortar and provide a quantifiable framework for mix optimization of alkali-activated materials.

Keywords:

Geopolymer mortar, Alkali activation, Compressive strength, Rheology and workability, Phase transformation

Supporting Agencies

No funding

References

L. Yan, B. Kasal, L. Huang (2016). A review of recent research on the use of cellulosic fibres, their fibre fabric reinforced cementitious, geopolymer and polymer composites in civil engineering, Compos. Part B Eng., 92, 94-132, https://doi.org/10.1016/j.compositesb.2016.02.002.

G.P. Lignola, V. Prota, F. Ceroni, E. Cosenza (2017). Performance assessment of basalt FRCM for retrofit applications on masonry, Compos. Part B Eng., 128, 1-18, https://doi.org/10.1016/j.compositesb.2017.05.003.

B. Lee, G. Kim, R. Kim, B. Cho, S. Lee, C. Chon (2017). Strength development properties of geopolymer paste and mortar with respect to amorphous Si/Al ratio of fly ash, Constr. Build.Mater., 151, 512-519, https://doi.org/10.1016/j.conbuildmat.2017.06.078.

S. Rocha, F. Pacheco-Torgal, Z.M. Zhang, J. Castro-Gomes, L.F. Ramos (2018). Metakaolin-based geopolymer mortars with different alkaline activators, Constr. Build.Mater., 178, 453-461, https://doi.org/10.1016/j.conbuildmat.2018.05.172.

M.N.S. Hadi, M. Al-Azzawi, T. Yu (2018). Effects of fly ash characteristics and alkaline activator components on compressive strength of fly ash-based geopolymer mortar, Constr. Build. Mater., 175, 41-54, https://doi.org/10.1016/j.conbuildmat.2018.04.092.

H.E. Elyamany, A.M. Elmoaty, M.A. Elmoaty, A.M. Elshaboury (2018). Magnesium sulfate resistance of geopolymer mortar, Constr. Build.Mater., 184, 111-127, https://doi.org/10.1016/j.conbuildmat.2018.06.212.

J.H. Zhuang, H.Y. Zhang, H. Xu (2017). Resistance of geopolymer mortar to acid and chloride attacks, Procedia Eng., 210, 126-131, https://doi.org/10.1016/j.proeng.2017.11.057.

N.A. Ulloa, H. Baykara, M.H. Cornejo, A. Rigail, C. Paredes, J.L. Gutierrez (2018). Application-oriented mix design optimization and characterization of zeolite-based geopolymer mortars, Constr. Build.Mater., 174, 138-149, https://doi.org/10.1016/j.conbuildmat.2018.04.101.

S. Kumer, S. Al-Deen, M. Ashraf, W. Hutchison (2020). Resistance of fly ash-based geopolymer mortar to both chemicals and high thermal cycles simultaneously, Constr. Build. Mater., 239, 117886, https://doi.org/10.1016/j.conbuildmat.2019.117886.

N.U. Kockal, T. Ozturan (2011). Durability of lightweight concretes with lightweight fly ash aggregates, Constr. Build. Mater., 25, 1430-1438, https://doi.org/10.1016/j.conbuildmat.2010.09.022.

F. Ameri, P. Shoaei, S. Alireza, B. Behforouz (2019). Geopolymers vs. alkali-activated materials (AAMs): A comparative study on durability, microstructure, and resistance to elevated temperatures of lightweight mortars, Constr. Build. Mater., 222, 49-63, https://doi.org/10.1016/j.conbuildmat.2019.06.079.

P. Shoaei, H. Reza, F. Mirlohi, S. Narimani, F. Ameri (2019). Waste ceramic powder-based geopolymer mortars: Effect of curing temperature and alkaline solution-to-binder ratio, Constr. Build. Mater., 227, 116686, https://doi.org/10.1016/j.conbuildmat.2019.116686.

M. Vafaei, A. Allahverdi, P. Dong, N. Bassim (2018). Acid attack on geopolymer cement mortar based on waste-glass powder and calcium aluminate cement at mild concentration, Constr. Build. Mater., 193, 363-372, https://doi.org/10.1016/j.conbuildmat.2018.10.203.

A. Gholampour, V.D. Ho, T. Ozbakkaloglu (2019). Ambient-cured geopolymer mortars prepared with waste-based sands: Mechanical and durability-related properties and microstructure, Compos. Part B Eng., 160, 519-534, https://doi.org/10.1016/j.compositesb.2018.12.057.

S. Jin, Y. Ji, C. Lu, H. Wei (2026). Viability of fiber-reinforced geopolymer mortar as a protective layer for coal gangue concrete piles in cold regions: Balancing materials, applications, and sustainability, Compos. Part B Eng., 312, 113336, https://doi.org/10.1016/j.compositesb.2025.113336.

M. Kaya, M. Junaid, S. Minhaj, S. Kazmi, O. Gencel (2026).Valorization of tile waste in geopolymer mortars: A sustainable approach using marble powder, fly ash, and silica fume, Powder Technol., 469, 121866, https://doi.org/10.1016/j.powtec.2025.121866.

A. Sharma, P. Singh, K. Kapoor (2022). Utilization of recycled fine powder as an activator in fly ash-based geopolymer mortar, Constr. Build.Mater., 323, 126581, https://doi.org/10.1016/j.conbuildmat.2022.126581.

S.J. Chithambaram, S. Kumar, M.M. Prasad (2020). Thermo-mechanical characteristics of geopolymer mortar, Constr. Build. Mater., 213, 100-108, https://doi.org/10.1016/j.conbuildmat.2019.04.051.

F. Sahin, M. Uysal, O. Canpolat, T. Cosgun, H. Dehghanpour (2021). The effect of polyvinyl fibers on metakaolin-based geopolymer mortars with different aggregate filling, Constr. Build.Mater., 300, 124257, https://doi.org/10.1016/j.conbuildmat.2021.124257.

Y. Wang, K. Peng, Y. Alrefaei, J. Dai (2021). The bond between geopolymer repair mortars and OPC concrete substrate: Strength and microscopic interactions, Cem. Concr.Compos., 119, 103991, https://doi.org/10.1016/j.cemconcomp.2021.103991.

J.C. Kuri, P.K. Sarker, F. Uddin, A. Shaikh (2021). Sulphuric acid resistance of ground ferronickel slag blended fly ash geopolymer mortar, Constr. Build. Mater., 313, 125505, https://doi.org/10.1016/j.conbuildmat.2021.125505.

J. Kwasny, T.A. Aiken, M.N. Soutsos, J.A. McIntosh, D.J. Cleland (2018). Sulfate and acid resistance of lithomarge-based geopolymer mortars, Constr. Build. Mater., 166, 537-553, https://doi.org/10.1016/j.conbuildmat.2018.01.129.

A. Akbar, F. Farooq, M. Shafique, F. Aslam, R. Alyousef (2021). Sugarcane bagasse ash-based engineered geopolymer mortar incorporating propylene fibers, J. Build.Eng., 33, 101492, https://doi.org/10.1016/j.jobe.2020.101492.

H. Rashidian-Dezfouli, P. Rao (2021). Study on the effect of selected parameters on the alkali-silica reaction of aggregate in ground glass fiber and fly ash-based geopolymer mortars, Constr. Build. Mater., 271, 121549, https://doi.org/10.1016/j.conbuildmat.2020.121549.

M. Hoy, S. Thandar, S. Horpibulsuk (2025). Strength and microstructural evaluation of sustainable geopolymer mortars using calcium carbonate sludge and fly ash as precursors, Case Stud. Constr. Mater., 23, e05189, https://doi.org/10.1016/j.cscm.2025.e05189.

K. Wang, P. Zhang, J. Guo, Z. Gao (2021). Single and synergistic enhancement on durability of geopolymer mortar by polyvinyl alcohol fiber, J. Mater.Res. Technol., 15, 1801-1814, https://doi.org/10.1016/j.jmrt.2021.09.036.

H.E. Elyamany, A.M. Elmoaty, M.A. Elmoaty, A.M. Elshaboury (2018). Setting time and 7-day strength of geopolymer mortar with various binders, Constr. Build.Mater., 187, 974-983, https://doi.org/10.1016/j.conbuildmat.2018.08.025.

J. Wang, L. Han, Z. Liu, D. Wang (2020). Setting controlling of lithium slag-based geopolymer by activator and sodium tetraborate as a retarder and its effects on mortar properties, Cem. Concr. Compos., 110, 103598, https://doi.org/10.1016/j.cemconcomp.2020.103598.

H. Ilcan, O. Sahin, A. Kul, G. Yildirim, M. Sahmaran (2022). Rheological properties and compressive strength of construction and demolition waste-based geopolymer mortars for 3D printing, Constr. Build.Mater., 328, 127114, https://doi.org/10.1016/j.conbuildmat.2022.127114.

Y. Sun, X. Wang, Y. Cao, Z. Chen, J. Fan, D. Liu (2025). Retardation behavior and mechanism of organic retarders on geopolymers at high temperatures and their effects on mortar properties, Constr. Build.Mater., 493, 143148, https://doi.org/10.1016/j.conbuildmat.2025.143148.

X. Shi, C. Zhang, X. Wang, T. Zhang, Q. Wang (2022). Response surface methodology for multi-objective optimization of fly ash-GGBS based geopolymer mortar, Constr. Build. Mater., 315, 125644, https://doi.org/10.1016/j.conbuildmat.2021.125644.

M. Vafaei, A. Allahverdi, P. Dong, N. Bassim, M. Mahinroosta (2021).Resistance of red clay brick waste/phosphorus slag-based geopolymer mortar to acid solutions of mild concentration, J. Build.Eng., 34, 102066, https://doi.org/10.1016/j.jobe.2020.102066.

X. Guo, G. Xiong (2021). Resistance of fiber-reinforced fly ash-steel slag based geopolymermortar to sulfate attack and drying-wetting cycles, Constr. Build. Mater., 269, 121326, https://doi.org/10.1016/j.conbuildmat.2020.121326.

W. Long, X. Zhang, J. Xie, S. Kou, Q. Luo, J. Wei (2022). Recycling of waste cathode ray tube glass through fly ash-slag geopolymer mortar, Constr. Build.Mater., 322, 126454, https://doi.org/10.1016/j.conbuildmat.2022.126454.

R. Kunthawatwong, L. Sylisomchanh, S. Pangdaeng, A. Wongsa (2022).Recycled non-biodegradable polyethylene terephthalate waste as fine aggregate in fly ash geopolymer and cement mortars, Constr. Build.Mater., 328, 127084, https://doi.org/10.1016/j.conbuildmat.2022.127084.

U. Durak, U. Bayram (2025). Recycled concrete aggregates in geopolymer mortars: Performance and environmental assessment, Constr. Build. Mater., 505, 144696, https://doi.org/10.1016/j.conbuildmat.2025.144696.

A. Albidah, A. Abadel, F. Alrshoudi, A. Altheeb, H. Abbas, Y. Al-Salloum (2020). Bond strength between concrete substrate and metakaolin geopolymer repair mortars at ambient and elevated temperatures, J. Mater. Res. Technol., 9, 10732-10745, https://doi.org/10.1016/j.jmrt.2020.07.092.

A. Wongsa, R. Kunthawatwong, S. Naenudon, V. Sata (2020). Natural fiber reinforced high calcium fly ash geopolymer mortar, Constr. Build. Mater., 241, 118143, https://doi.org/10.1016/j.conbuildmat.2020.118143.

J. Sai, D. Neeraja (2018). Properties of class F fly ash based geopolymer mortar produced with alkaline water, J. Build. Eng., 19, 42-48, https://doi.org/10.1016/j.jobe.2018.04.031.

C. Suksiripattanapong, K. Krosoongnern (2020). Properties of cellular lightweight high-calcium bottom ash-Portland cement geopolymer mortar, Case Stud. Constr. Mater., 12, e00337, https://doi.org/10.1016/j.cscm.2020.e00337.

O.A. Abdulkareem, M. Ramli, J.C. Matthews (2019). Production of geopolymer mortar system containing high calcium biomass wood ash as a partial substitution to fly ash: An early age evaluation, Compos. Part B Eng., 174, 106941, https://doi.org/10.1016/j.compositesb.2019.106941.

S. Jiang, X. Wang, K. Qi, X. Wan (2025). Preparation and performance of a fast-hardening red mud based geopolymer repair mortar complexed with FGD, J. Build. Eng., 108, 112980, https://doi.org/10.1016/j.jobe.2025.112980.

T. Yang, H. Zhu, Z. Zhang (2017). Influence of fly ash on the pore structure and shrinkage characteristics of metakaolin-based geopolymer pastes and mortars, Constr. Build. Mater., 153, 284-293, https://doi.org/10.1016/j.conbuildmat.2017.05.067.

Y. Wang, S. Jin, X. Wang, T. Zhu, Q. Wang (2025). Polyvinyl alcohol fiber reinforced electrolytic manganese slag based geopolymer mortar: Mechanical properties and microstructure, Constr. Build. Mater., 477, 141390, https://doi.org/10.1016/j.conbuildmat.2025.141390.

G.A. Soares, B.P. Bezerra, J.G. Antoniazzi, M.D.M. Innocentini (2025). Physico-mechanical and thermal behavior of foamed mortars bonded with Portland cement or metakaolin-based geopolymer, J. Build. Eng., 111, 113644, https://doi.org/10.1016/j.jobe.2025.113644.

Y. Wang, K. Takasu, Q. Zhao, K. Harada, Z. Liu, H. Suyama (2025). Performance optimization and carbon reduction potential of bamboo biochar fine aggregates for sustainable geopolymer mortars, Constr. Build. Mater., 497, 143905, https://doi.org/10.1016/j.conbuildmat.2025.143905.

M.G. Khalil, F. Elgabbas, M.S. El-Feky, H. El-Shafie (2020). Performance of geopolymer mortar cured under ambient temperature, Constr. Build. Mater., 242, 118090, https://doi.org/10.1016/j.conbuildmat.2020.118090.

P. Darvish, U.J. Alengaram, Y. Soon, S. Ibrahim, S. Yusoff (2020).Performance evaluation of palm oil clinker sand as replacement for conventional sand in geopolymer mortar, Constr. Build.Mater., 258, 120352, https://doi.org/10.1016/j.conbuildmat.2020.120352.

A. Bhutta, M. Farooq, N. Banthia (2019). Performance characteristics of micro fiber-reinforced geopolymer mortars for repair, Constr. Build.Mater., 215, 605-612, https://doi.org/10.1016/j.conbuildmat.2019.04.210.

Y. Wang, X. Liu, Z. Zhang, Y. Li (2025). Performance and strength mechanism of aeolian sand mortar solidified by coal gangue-slag geopolymers, Case Stud. Constr. Mater., 23, e05567, https://doi.org/10.1016/j.cscm.2025.e05567.

A. El Abd, S.E. Kichanov, M. Taman, R.M. Nazarov (2020). Penetration of water into cracked geopolymer mortars by means of neutron radiography, Constr. Build. Mater., 256, 119471, https://doi.org/10.1016/j.conbuildmat.2020.119471.

W. Ye, H. Kruppa, A. Vollpracht, Y. Tan (2025). Paste rheological behavior and mortar workability of siliceous fly ash geopolymer, Constr. Build. Mater., 486, 142050, https://doi.org/10.1016/j.conbuildmat.2025.142050.

D. Wang, K. Zou, S. Zhu, L. Guo (2025). Optimization of mix proportions and mechanical properties of coal gangue-based multi-solid-waste geopolymer mortars, Case Stud. Constr. Mater., 23, e05134, https://doi.org/10.1016/j.cscm.2025.e05134.

L. Yan, Y. Li, F. Gao, X. Wang, H. Xu, R. Hai (2025). Optimization of mix proportion design for expanded perlite geopolymer insulating mortar based on mixture design, Constr. Build. Mater., 491, 142641, https://doi.org/10.1016/j.conbuildmat.2025.142641.

E. Luga, C. Duran (2018). Optimization of heat cured fly ash/slag blend geopolymer mortars designed by Combined Design method: Part 1, Constr. Build. Mater., 178, 393-404, https://doi.org/10.1016/j.conbuildmat.2018.05.140.

H.M. Khater, M. Ghareib (2020). Optimization of geopolymer mortar incorporating heavy metals in producing dense hybrid composites, J. Build.Eng., 32, 101684, https://doi.org/10.1016/j.jobe.2020.101684.

A. Hasnaoui, E. Ghorbel, G. Wardeh (2019). Optimization approach of granulated blast furnace slag and metakaolin based geopolymer mortars, Constr. Build. Mater., 198, 10-26, https://doi.org/10.1016/j.conbuildmat.2018.11.251.

A. Wongsa, R. Kunthawatwong, S. Naenudon, V. Sata, P. Chindaprasirt (2020). Natural fiber reinforced high calcium fly ash geopolymer mortar, Constr. Build. Mater., 241, 118143, https://doi.org/10.1016/j.conbuildmat.2020.118143.

M. Kaur, J. Singh, M. Kaur (2018). Microstructure and strength development of fly ash-based geopolymer mortar: Role of nano-metakaolin, Constr. Build. Mater., 190, 672-679, https://doi.org/10.1016/j.conbuildmat.2018.09.157.

J.C. Kuri, S. Majhi, P.K. Sarker, A. Mukherjee (2021). Microstructural and non-destructive investigation of the effect of high temperature exposure on ground ferronickel slag blended fly ash geopolymer mortars, J. Build. Eng., 43, 103099, https://doi.org/10.1016/j.jobe.2021.103099.

A. Naghizadeh, S.O. Ekolu (2019). Method for comprehensive mix design of fly ash geopolymer mortars, Constr. Build. Mater., 202, 704-717, https://doi.org/10.1016/j.conbuildmat.2018.12.185.

I. Skyrianou, L.N. Koutas, C.G. Papakonstantinou (2025). Metakaolin-based geopolymer mortars: Influence of mix design on mechanical properties and durability, Constr. Build. Mater., 490, 142526, https://doi.org/10.1016/j.conbuildmat.2025.142526.

A. Naghizadeh, S.O. Ekolu, M. Welman-Purchase, L. Lagrange, L.N. Tchadjie (2025). Effective recycled binder produced upon thermal activation to enhance mechanical properties of fly ash-based geopolymer mortars, Dev. Built Environ., 23, 100688,

https://doi.org/10.1016/j.dibe.2025.100688.

M. Sun, Z. Li, Z. Li, Q. Xu, B. Zou, H. Liu, F. Wang (2025). Mechanical and microstructural properties of graphite tailings based geopolymer mortars at high temperature, Case Stud. Constr. Mater., 23, e05388, https://doi.org/10.1016/j.cscm.2025.e05388.

A. Erfanimanesh, M.K. Sharbatdar (2020). Mechanical and microstructural characteristics of geopolymer paste, mortar, and concrete containing local zeolite and slag activated by sodium carbonate, J. Build.Eng., 32, 101781, https://doi.org/10.1016/j.jobe.2020.101781.

M. Ziada, H. Tanyildizi, A. Coskun (2025). Mechanical and microstructural properties of basalt fiber reinforced underwater geopolymer mortar, Structures, 75, 108814, https://doi.org/10.1016/j.istruc.2025.108814.

K. Chen, D. Wu, M. Yi, Q. Cai, Z. Zhang (2021). Mechanical and durability properties of metakaolin blended with slag geopolymer mortars used for pavement repair, Constr. Build. Mater., 281, 122566, https://doi.org/10.1016/j.conbuildmat.2021.122566.

Y. Yang, W. Zhou, Y. Yang, I. Mithal, X. Lu, Y. Zhang (2025). Fatigue behavior and microstructural mechanisms of fly ash-slag based geopolymer mortars under cyclic loading, Constr. Build. Mater., 494, 143236, https://doi.org/10.1016/j.conbuildmat.2025.143236.

G. Fahim, M. Ismail, N. Hafizah, A. Khalid (2018). Compressive strength and microstructure of assorted wastes incorporated geopolymer mortars: Effect of solution molarity, Alexandria Eng. J., 57, 3375-3386, https://doi.org/10.1016/j.aej.2018.07.011.

C. Ng, U.J. Alengaram, L. Sing, K. Hung, M. Zamin, S. Ramesh (2018). A review on microstructural study and compressive strength of geopolymer mortar, paste and concrete, Constr. Build.Mater., 186, 550-576, https://doi.org/10.1016/j.conbuildmat.2018.07.075.

W. Huang, H. Wang (2024). Comprehensive assessment of engineering and environmental attributes of geopolymer pervious concrete with natural and recycled aggregate, J. Clean.Prod., 468, 143138, https://doi.org/10.1016/j.jclepro.2024.143138.

K. Walbruck, L. Drewler, S. Witzleben, D. Stephan (2021).Factors influencing thermal conductivity and compressive strength of natural fiber-reinforced geopolymer foams, Open Ceram., 5, 100065, https://doi.org/10.1016/j.oceram.2021.100065.

B. Bayrak, A. Benli, H.G. Alcan, O. Celebi, G. Kaplan, A.C. Aydin (2023). Recycling of waste marble powder and waste colemanite in ternary-blended green geopolymer composites: Mechanical, durability and microstructural properties, J. Build.Eng., 73, 106661, https://doi.org/10.1016/j.jobe.2023.106661.

M.S. Saif, M.O.R. El-Hariri, A.I. Sarie-Eldin, B.A. Tayeh, M.F. Farag (2022). Impact of Ca+ content and curing condition on durability performance of metakaolin-based geopolymer mortars, Case Stud. Constr. Mater., 16, e00922, https://doi.org/10.1016/j.cscm.2022.e00922.

A.R. Villca, F. Vargas, J. Araya, L. Rojas, C. Villarroel (2021). Lime/pozzolan/geopolymer systems: Performance in pastes and mortars, Constr. Build. Mater., 276, 122208, https://doi.org/10.1016/j.conbuildmat.2020.122208.

F. Longo, P. Lassandro, A. Moshiri, T. Phatak, M.A. Aiello, K.J. Krakowiak (2020). Lightweight geopolymer-based mortars for the structural and energy retrofit of buildings, Energy Build., 225, 110352, https://doi.org/10.1016/j.enbuild.2020.110352.

Z. Sun, A. Vollpracht (2020). Leaching of monolithic geopolymer mortars, Cem.Concr.Res., 136, 106161, https://doi.org/10.1016/j.cemconres.2020.106161.

A. Lo Bianco, F. Armetta, M.M. Calvino, G.E. Gagliardo Briuccia, B. Macalik, D. Hreniak, M.L. Saladino, G. Lazzara, G. Cavallaro (2026). Invisible near-infrared luminescent marker incorporating Egyptian blue in halloysite-based geopolymer mortars: Applications in covert tagging, J. Alloys Compd., 1050, 185458, https://doi.org/10.1016/j.jallcom.2025.185458.

B.B. Jindal (2019). Investigations on the properties of geopolymer mortar and concrete with mineral admixtures: A review, Constr. Build. Mater., 227, 116644, https://doi.org/10.1016/j.conbuildmat.2019.08.025.

I. Tank, S.K. Sharma, A. Goyal (2026). Investigation on fly ash-based geopolymer mortar: Effect of mix proportions and curing conditions on mechanical properties and durability characteristics of optimized mix, Next Mater., 10, 101565, https://doi.org/10.1016/j.nxmate.2025.101565.

H. Liu, X. Dai, P. Zhu, X. Wang, M. Zong, J. Feng (2024). Acid rain resistance of geopolymer recycled pervious concrete featuring top-bottom interconnected pores under freeze-thaw cycles and fatigue loads, J. Build. Eng., 96, 110356, https://doi.org/10.1016/j.jobe.2024.110356.

Z. Gao, P. Zhang, J. Wang, K. Wang, T. Zhang (2022). Interfacial properties of geopolymer mortar and concrete substrate: Effect of polyvinyl alcohol fiber and nano-SiO2 contents, Constr. Build. Mater., 315, 125735, https://doi.org/10.1016/j.conbuildmat.2021.125735.

A.K. Kaya, M.I. Onur (2025). Optimization of physical, mechanical and thermal properties of two-part geopolymer mortar by Taguchi method, Constr. Build.Mater., 476, 141208, https://doi.org/10.1016/j.conbuildmat.2025.141208.

P.W. Ariyadasa, A.C. Manalo, W. Lokuge, V. Aravinthan, A. Gerdes, J. Kaltenbach (2025). Degradation mechanisms of low-calcium fly ash-based geopolymer mortar in simulated aggressive sewer conditions, Cem.Concr.Res., 194, 107882, https://doi.org/10.1016/j.cemconres.2025.107882.

P. Zhang, Y. Zheng, K. Wang, J. Zhang (2018). A review on properties of fresh and hardened geopolymer mortar, Compos. Part B Eng., 152, 79-95, https://doi.org/10.1016/j.compositesb.2018.06.031.

G. Silva, S. Kim, B. Bertolotti, J. Nakamatsu, R. Aguilar (2020). Optimization of a reinforced geopolymer composite using natural fibers and construction wastes, Constr. Build.Mater., 258, 119697,https://doi.org/10.1016/j.conbuildmat.2020.119697.

P. Zhu, X. Chen, H. Liu, Z. Wang, C. Chen, H. Li (2024). Recycling of waste recycled aggregate concrete in freeze-thaw environment and emergy analysis of concrete recycling system, J. Build.Eng., 96, 110377, https://doi.org/10.1016/j.jobe.2024.110377.

T. Bezabih, D. Sinkhonde, D. Mirindi, S. Kiprop, F. Mirindi, O. Abiodun (2025). Effects of mix design parameters on workability and compressive strength of teff straw ash-based geopolymer mortars: Experimental evaluation and machine learning prediction, Constr. Build. Mater., 502, 144487, https://doi.org/10.1016/j.conbuildmat.2025.144487.

N. Bheel, P. Awoyera, T. Tafsirojjaman, N.H. Sor, S. Sohu (2021). Synergic effect of metakaolin and groundnut shell ash on the behavior of fly ash-based self-compacting geopolymer concrete, Constr. Build.Mater., 311, 125327, https://doi.org/10.1016/j.conbuildmat.2021.125327.

A. Raza, B. Ahmed, M.H. El Ouni, W. Chen (2024). Mechanical, durability and microstructural characterization of cost-effective polyethylene fiber-reinforced geopolymer concrete, Constr. Build.Mater., 432, 136661, https://doi.org/10.1016/j.conbuildmat.2024.136661.

H. Altawil (2025). Influence of saline exposure and freeze-thaw effects on class C fly ash geopolymer mortars using the Taguchi method, Results Eng., 27, 106836, https://doi.org/10.1016/j.rineng.2025.106836.

T. Cakmak, I. Ustabas, E. Yilmaz (2025). Integrating obsidian and silica fume in geopolymer mortars: Strength prediction via meta-ensemble machine learning framework, Dev. Built Environ., 24, 100820, https://doi.org/10.1016/j.dibe.2025.100820.

G. Ogwang, P.W. Olupot, H. Kasedde, E. Menya, H. Storz, Y. Kiros (2021). Experimental evaluation of rice husk ash for applications in geopolymer mortars, J. Bioresour. Bioprod., 6, 160-167, https://doi.org/10.1016/j.jobab.2021.02.008.

L. Masoud, A. Hammoud, Y. Mortada, E. Masad (2024). Rheological, mechanical, and microscopic properties of polypropylene fiber reinforced-geopolymer concrete for additive manufacturing, Constr. Build. Mater., 438, 137069, https://doi.org/10.1016/j.conbuildmat.2024.137069.

S. Kumar, S. Shrivastava (2021). Influence of molarity and alkali mixture ratio on ambient temperature cured waste cement concrete based geopolymer mortar, Constr. Build. Mater., 301, 124380, https://doi.org/10.1016/j.conbuildmat.2021.124380.

R. Vijayalakshmi (2021). Recent studies on the properties of pervious concrete: A sustainable solution for pavements and water treatment, Civ. Environ. Eng. Rep., 31, 54-84, https://doi.org/10.2478/ceer-2021-0034.

R.A. Mahmood, E. Delik, N.U. Kockal, B.E. Tefon-Ozturk (2025). Performance of bio-geopolymer mortar incorporation isolates of Bacillus cereus and Bacillus subtilis: A comprehensive experimental study, Next Mater., 8, 100845, https://doi.org/10.1016/j.nxmate.2025.100845.

M. Saba, J.J. Assaad (2021). Effect of recycled fine aggregates on performance of geopolymer masonry mortars, Constr. Build. Mater., 279, 122461, https://doi.org/10.1016/j.conbuildmat.2021.122461.

Z. Huang, J. Ling, J. Zhang, J. Li, H. Yang, Y. Zheng (2026). Influence of functional admixtures on the strength and shrinkage of seawater sea sand geopolymer mortar, Constr. Build. Mater., 513, 145504, https://doi.org/10.1016/j.conbuildmat.2026.145504.

A.S. Bature, M. Khorami, E. Ganjian, M. Tyrer (2021). Influence of alkali activator type and proportion on strength performance of calcined clay geopolymer mortar, Constr. Build. Mater., 267, 120446, https://doi.org/10.1016/j.conbuildmat.2020.120446.

Z. Sun, X. Lin, A. Vollpracht (2018). Pervious concrete made of alkali activated slag and geopolymers, Constr. Build. Mater., 189, 797-803, https://doi.org/10.1016/j.conbuildmat.2018.09.067.

M. Jin, Z. Wang, F. Lian, P. Zhao (2020).Freeze-thaw resistance and seawater corrosion resistance of optimized tannery sludge/metakaolin-based geopolymer, Constr. Build.Mater., 265, 120730, https://doi.org/10.1016/j.conbuildmat.2020.120730.

L. Niu, X. Nie, N. Li, J. Guan, L. Li, C. Xie (2026). Experimental and theoretical investigation of fiber-reinforced geopolymer mortars: Mix design optimization and bond behavior with brick masonry, Case Stud. Constr. Mater., 24, e05767, https://doi.org/10.1016/j.cscm.2026.e05767.

E.K. Mermerdas, Z. Algin (2020).Experimental assessment and optimization of mix parameters of fly ash-based lightweight geopolymer mortar with respect to shrinkage and strength, J. Build.Eng., 31, 101351, https://doi.org/10.1016/j.jobe.2020.101351.

H. Hamisi, S.T. Chambua, S. Mansouri, H. Majdoubi (2025).Compressive strength optimization of the ambient-cured metakaolin-based geopolymer mortar using the Taguchi design approach, Constr. Build.Mater., 475, 141248, https://doi.org/10.1016/j.conbuildmat.2025.141248.

D. Huang, C. Lin, Z. Liu, Y. Lu, S. Li (2024). Compressive behaviors of steel fiber-reinforced geopolymer recycled aggregate concrete-filled GFRP tube columns, Structures, 66, 106829, https://doi.org/10.1016/j.istruc.2024.106829.

H. Baykara, M.H. Cornejo, E. Garcia, N. Ulloa (2020). Preparation, characterization, and evalua-tion of compressive strength of polypropylene fiber reinforced geopolymer mortars, Heliyon, 6, e03755, https://doi.org/10.1016/j.heliyon.2020.e03755.

M. Upshaw, C.S. Cai (2021). Feasibility study of MK-based geopolymer binder for RAC applications: Effects of silica fume and added CaO on compressive strength of mortar samples, Case Stud. Constr. Mater., 14, e00500, https://doi.org/10.1016/j.cscm.2021.e00500.

A. Grinys, M. Statkauskas (2025).Effect of elevated temperature on mechanical properties of ceramic brick and metakaolin waste-based geopolymer mortar, Constr. Build.Mater., 470, 140431, https://doi.org/10.1016/j.conbuildmat.2025.140431.

P. Yoosuk, C. Suksiripattanapong, P. Sukontasukkul (2021). Properties of polypropylene fiber reinforced cellular lightweight high calcium fly ash geopolymer mortar, Case Stud. Constr. Mater., 15, e00730, https://doi.org/10.1016/j.cscm.2021.e00730.

P. Darvish, U.J. Alengaram, A. Mahmoud, Y. Soon, S. Ibrahim (2021). Enunciation of size effect of sustainable palm oil clinker sand on the characteristics of cement and geopolymer mortars, J. Build.Eng., 44, 103335, https://doi.org/10.1016/j.jobe.2021.103335.

X. Liang, Y. Ji (2021).Experimental study on durability of red mud-blast furnace slag geopolymer mortar, Constr. Build.Mater., 267, 120942, https://doi.org/10.1016/j.conbuildmat.2020.120942.

T.H. Vu, N. Gowripalan, P. De Silva, A. Paradowska, U. Garbe, P. Kidd, V. Sirivivatnanon (2020). Assessing carbonation in one-part fly ash/slag geopolymer mortar: Change in pore characteristics using the state-of-the-art technique neutron tomography, Cem. Concr.Compos., 114, 103759, https://doi.org/10.1016/j.cemconcomp.2020.103759.

L. Hong, W. Tang, Y. Tan, Y. Wang, B. Guo, P. Gao (2025). Effect of short fibers on non-uniform strain distribution of geopolymer mortar under dry conditions, Constr. Build.Mater., 459, 139768, https://doi.org/10.1016/j.conbuildmat.2024.139768.

P. Duxson, J.L. Provis, G.C. Lukey, J.S.J. van Deventer (2007).The role of inorganic polymer technology in the development of green concrete, Cem.Concr.Res., 37, 1590-1597, https://doi.org/10.1016/j.cemconres.2007.08.018.

Z. Jiao, X. Li, Q. Yu (2021).Effect of curing conditions on freeze-thaw resistance of geopolymer mortars containing various calcium resources, Constr. Build.Mater., 313, 125507, https://doi.org/10.1016/j.conbuildmat.2021.125507.

H. Zhang, J. Liu, B. Wu (2021).Mechanical properties and reaction mechanism of one-part geopolymer mortars, Constr. Build.Mater., 273, 121973, https://doi.org/10.1016/j.conbuildmat.2020.121973.

G.A. Ramos, P.R. de Matos, F. Pelisser, P.J.P. Gleize (2020). Effect of porcelain tile polishing residue on eco-efficient geopolymer: Rheological performance of pastes and mortars, J. Build. Eng., 32, 101699, https://doi.org/10.1016/j.jobe.2020.101699