{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,1]],"date-time":"2026-10-01T00:10:04Z","timestamp":1790813404018,"version":"4.1.0"},"reference-count":53,"publisher":"MDPI AG","issue":"14","license":[{"start":{"date-parts":[[2026,7,20]],"date-time":"2026-07-20T00:00:00Z","timestamp":1784505600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Youth Innovation Talent Project of Ordinary Universities in Guangdong Province","award":["2024KQNCX236"],"award-info":[{"award-number":["2024KQNCX236"]}]},{"name":"Guangzhou Education Bureau\u2019s Higher Education Research Project","award":["2024312019"],"award-info":[{"award-number":["2024312019"]}]},{"award":["2024312019"],"award-info":[{"award-number":["2024312019"]}],"id":[{"id":"https:\/\/ror.org\/00479t136","id-type":"ROR","asserted-by":"publisher"}]},{"name":"Guangzhou City Polytechnic\u2019s 2025 Annual School-level Research Project","award":["KYBS2025002"],"award-info":[{"award-number":["KYBS2025002"]}]},{"award":["KYBS2025002"],"award-info":[{"award-number":["KYBS2025002"]}],"id":[{"id":"https:\/\/ror.org\/059h57z85","id-type":"ROR","asserted-by":"publisher"}]},{"name":"the Key Scientific Research Project Plan of Colleges and Universities in Henan Province","award":["26A56001"],"award-info":[{"award-number":["26A56001"]}]},{"name":"the Henan Provincial Natural Science Foundation for Youths (Category C) Project","award":["262300420385"],"award-info":[{"award-number":["262300420385"]}]},{"name":"the Key Research Platform and Project of Ordinary Universities in 2023","award":["2023ZDZX307"],"award-info":[{"award-number":["2023ZDZX307"]}]},{"name":"the Research Project of Guangzhou Municipal Universities in 2024","award":["2024312309"],"award-info":[{"award-number":["2024312309"]}]},{"name":"the Education Science Planning Project of the Guangdong Provincial Department of Education in 2025","award":["2025GXGK0247"],"award-info":[{"award-number":["2025GXGK0247"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>Geopolymer research has usually focused on predicting compressive strength at specific curing ages, while the underlying strength-development behavior remains insufficiently understood. To address this gap, this study proposes a pathway-oriented framework for characterizing strength-development patterns in one-part geopolymers (OPGs). A compiled experimental database was established from published studies, and three dimensionless indices, namely the Early Strength Index (ESI), Mid-age Strength Index (MSI), and Late-stage Growth Potential (LGP), were introduced to quantify temporal strength-development behavior. Then, Gaussian Mixture Model (GMM) clustering was employed in the ESI\u2013MSI\u2013LGP feature space to identify latent strength-development pathways. Based on the available core dataset, three representative strength-development pathways were identified: Fast-hardening, Delayed-hardening, and Balanced-hardening. The Fast-hardening pathway exhibited the highest average ESI and MSI values, indicating rapid early- and mid-age strength attainment. The Delayed-hardening pathway showed lower ESI and MSI values but the highest LGP value, reflecting stronger later-age strength-growth potential after 7 days. The Balanced-hardening pathway was characterized by relatively low ESI, high MSI, and low LGP, suggesting accelerated strength development between 3 and 7 days. Further analysis of mix-design variables indicated that pathway formation was associated with the coupled effects of aggregate-to-binder proportion, activator chemistry, water availability, precursor composition, and curing conditions, rather than being controlled by a single dominant factor. Finally, a smooth probability-based strength-development map was established in the ESI\u2013MSI feature space, providing a practical visualization tool for approximate pathway identification and preliminary mixture-selection support. The proposed framework shifts the focus from conventional strength prediction toward strength-development behavior characterization and offers new insights into the macroscopic hardening patterns of one-part geopolymers.<\/jats:p>","DOI":"10.3390\/ma19143108","type":"journal-article","created":{"date-parts":[[2026,7,20]],"date-time":"2026-07-20T09:32:54Z","timestamp":1784539974000},"page":"3108","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Identification of Strength-Development Pathways in One-Part Geopolymers Using ESI\u2013MSI\u2013LGP Indices and GMM Clustering"],"prefix":"10.3390","volume":"19","author":[{"given":"Yiming","family":"Li","sequence":"first","affiliation":[{"name":"School of Smart Urban Construction, Guangzhou City Polytechnic, Guangzhou 511370, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3497-0254","authenticated-orcid":false,"given":"Zhenzhu","family":"Meng","sequence":"additional","affiliation":[{"name":"School of Hydraulic Engineering, Zhejiang University of Water Resources and Electric Power, Hangzhou 310018, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jian","family":"Huang","sequence":"additional","affiliation":[{"name":"School of Smart Urban Construction, Guangzhou City Polytechnic, Guangzhou 511370, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yanwu","family":"Xiao","sequence":"additional","affiliation":[{"name":"School of Smart Urban Construction, Guangzhou City Polytechnic, Guangzhou 511370, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Zhibin","family":"Liu","sequence":"additional","affiliation":[{"name":"School of Civil Engineering and Architecture, Anyang Normal University, Anyang 455000, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Duo","family":"Zhang","sequence":"additional","affiliation":[{"name":"School of Civil Engineering, Sun Yat-sen University, Zhuhai 519082, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Pinxue","family":"Chen","sequence":"additional","affiliation":[{"name":"School of Smart Urban Construction, Guangzhou City Polytechnic, Guangzhou 511370, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,7,20]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"2252","DOI":"10.1016\/j.rser.2011.02.014","article-title":"A review on emission analysis in cement industries","volume":"15","author":"Ali","year":"2011","journal-title":"Renew. Sustain. Energy Rev."},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Abiodun, Y.O., Olanrewaju, O.A., Gbenebor, O.P., Ochulor, E.F., Obasa, D.V., and Adeosun, S.O. (2022). Cutting cement industry CO2 emissions through metakaolin use in construction. Atmosphere, 13.","DOI":"10.3390\/atmos13091494"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"1844","DOI":"10.1016\/j.istruc.2022.08.092","article-title":"Life cycle resilience assessment of RC frame structures considering multiple-hazard","volume":"44","author":"Li","year":"2022","journal-title":"Structures"},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"31","DOI":"10.1016\/j.clay.2015.04.023","article-title":"Geopolymer from kaolin in China: An overview","volume":"119","author":"Zhang","year":"2016","journal-title":"Appl. Clay Sci."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"21","DOI":"10.1016\/j.cemconres.2017.10.001","article-title":"One-part alkali-activated materials: A review","volume":"103","author":"Luukkonen","year":"2018","journal-title":"Cem. Concr. Res."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"225","DOI":"10.1007\/s12649-016-9582-5","article-title":"Characterisation of one-part geopolymer binders made from fly ash","volume":"8","author":"Hajimohammadi","year":"2017","journal-title":"Waste Biomass Valorization"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"5696","DOI":"10.1016\/j.ceramint.2014.12.154","article-title":"Synthesis of heat and ambient cured one-part geopolymer mixes with different grades of sodium silicate","volume":"41","author":"Nematollahi","year":"2015","journal-title":"Ceram. Int."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"636","DOI":"10.1016\/j.jclepro.2018.08.060","article-title":"Preparation of cleaner one-part geopolymer by investigating different types of commercial sodium metasilicate in China","volume":"201","author":"Ma","year":"2018","journal-title":"J. Clean. Prod."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.jclepro.2019.03.290","article-title":"Fresh and hardened properties of one-part fly ash-based geopolymer binders cured at room temperature: Effect of slag and alkali activators","volume":"225","author":"Oderji","year":"2019","journal-title":"J. Clean. Prod."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"118533","DOI":"10.1016\/j.conbuildmat.2020.118533","article-title":"Improvement of early strength of fly ash-slag based one-part alkali activated mortar","volume":"246","author":"Shah","year":"2020","journal-title":"Constr. Build. Mater."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"124880","DOI":"10.1016\/j.conbuildmat.2021.124880","article-title":"Roles of hybrid activators in improving the early-age properties of one-part geopolymer pastes","volume":"306","author":"Wang","year":"2021","journal-title":"Constr. Build. Mater."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"188","DOI":"10.1016\/j.jclepro.2019.02.159","article-title":"Properties and characterization of green one-part geopolymer activated by composite activators","volume":"220","author":"Ma","year":"2019","journal-title":"J. Clean. Prod."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"686","DOI":"10.1016\/j.jclepro.2019.02.116","article-title":"Cleaner one-part geopolymer prepared by introducing fly ash sinking spherical beads: Properties and geopolymerization mechanism","volume":"219","author":"Guo","year":"2019","journal-title":"J. Clean. Prod."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"105928","DOI":"10.1016\/j.cemconcomp.2025.105928","article-title":"Enhancing the workability retention of one-part alkali activated binders by adjusting the chemistry of the activators","volume":"157","author":"Gao","year":"2025","journal-title":"Cem. Concr. Compos."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"207","DOI":"10.1016\/j.jiec.2024.03.006","article-title":"Preparation of one-part geopolymers using coal gasification slag: Effect of alkali fusion product additive and liquid\/solid ratio","volume":"137","author":"Chen","year":"2024","journal-title":"J. Ind. Eng. Chem."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"136544","DOI":"10.1016\/j.conbuildmat.2024.136544","article-title":"Biomass ash waste from agricultural residues: Characterisation, reactivity and potential to develop one-part geopolymer cement","volume":"431","author":"Lei","year":"2024","journal-title":"Constr. Build. Mater."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"138466","DOI":"10.1016\/j.conbuildmat.2024.138466","article-title":"Utilizing raw phosphogypsum to prepare one-part geopolymer: Mechanical properties, optimization, and hydration mechanisms","volume":"449","author":"Zhang","year":"2024","journal-title":"Constr. Build. Mater."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"141129","DOI":"10.1016\/j.jclepro.2024.141129","article-title":"Synthesis of one-part geopolymers from alkaline-activated molybdenum tailings: Mechanical properties and microstructural evolution","volume":"443","author":"Yang","year":"2024","journal-title":"J. Clean. Prod."},{"key":"ref_19","first-page":"e03444","article-title":"Enhancing solidification in one-part geopolymer systems through alkali-thermal activation of bauxite residue and silica fume integration","volume":"21","author":"Konduru","year":"2024","journal-title":"Case Stud. Constr. Mater."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"140067","DOI":"10.1016\/j.conbuildmat.2025.140067","article-title":"The effects of solid activator dosage and the liquid-solid ratio on the properties of FA-GGBS based one-part geopolymer","volume":"463","author":"Chen","year":"2025","journal-title":"Constr. Build. Mater."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"121030","DOI":"10.1016\/j.conbuildmat.2020.121030","article-title":"Effects of mixing water temperatures on properties of one-part alkali-activated slag paste","volume":"266","author":"Almakhadmeh","year":"2021","journal-title":"Constr. Build. Mater."},{"key":"ref_22","first-page":"e02677","article-title":"One-part slag\/zeolite geopolymer mortars under ambient and heat curing conditions","volume":"20","author":"Shoaei","year":"2024","journal-title":"Case Stud. Constr. Mater."},{"key":"ref_23","doi-asserted-by":"crossref","unstructured":"Srinivasa, A.S., Swaminathan, K., and Yaragal, S.C. (2023). Effect of slag and solid activator on flowability and compressive strength of fly ash based one-part geopolymer pastes. Mater. Today Proc.","DOI":"10.1016\/j.matpr.2023.03.481"},{"key":"ref_24","first-page":"e01946","article-title":"Microstructural and optimization studies on novel one-part geopolymer pastes by Box-Behnken response surface design method","volume":"18","author":"Srinivasa","year":"2023","journal-title":"Case Stud. Constr. Mater."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"133772","DOI":"10.1016\/j.conbuildmat.2023.133772","article-title":"Multi-objective optimization of one-part geopolymer mortars adopting response surface method","volume":"409","author":"Srinivasa","year":"2023","journal-title":"Constr. Build. Mater."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"105480","DOI":"10.1016\/j.jobe.2022.105480","article-title":"Strength optimization and key factors correlation of one-part fly ash\/ladle furnace slag (FA\/LFS) geopolymer using statistical approach","volume":"63","author":"Hang","year":"2023","journal-title":"J. Build. Eng."},{"key":"ref_27","doi-asserted-by":"crossref","unstructured":"Faridmehr, I., Sahraei, M.A., Nehdi, M.L., and Valerievich, K.A. (2023). Optimization of fly ash\u2014slag one-part geopolymers with improved properties. Materials, 16.","DOI":"10.3390\/ma16062348"},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"106978","DOI":"10.1016\/j.jobe.2023.106978","article-title":"Assessing the viability of a high performance one-part geopolymer made from fly ash and GGBS at ambient temperature","volume":"75","author":"Ma","year":"2023","journal-title":"J. Build. Eng."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"138202","DOI":"10.1016\/j.conbuildmat.2024.138202","article-title":"Evaluation of chemo-physio-mechanical characteristics of GGBS-MBS-based ready-mix geopolymer under ambient curing condition","volume":"449","author":"Godani","year":"2024","journal-title":"Constr. Build. Mater."},{"key":"ref_30","first-page":"525","article-title":"Artificial Intelligence Prediction of One-Part Geopolymer Compressive Strength for Sustainable Concrete","volume":"141","author":"Iqbal","year":"2024","journal-title":"CMES-Comput. Model. Eng. Sci."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"3016498","DOI":"10.1155\/stc\/3016498","article-title":"A Novel Permutation Entropy\u2013Based Method for Assessing the Stability of Seawalls on Soft Soils","volume":"2026","author":"Qin","year":"2026","journal-title":"Struct. Control Health Monit."},{"key":"ref_32","doi-asserted-by":"crossref","unstructured":"Meng, Z., Hu, Y., Jiang, S., Zheng, S., Zhang, J., Yuan, Z., and Yao, S. (2025). Slope Deformation Prediction Combining Particle Swarm Optimization-Based Fractional-Order Grey Model and K-Means Clustering. Fractal Fract., 9.","DOI":"10.3390\/fractalfract9040210"},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Li, J., Meng, Z., Zhang, J., Chen, Y., Yao, J., Li, X., Qin, P., Liu, X., and Cheng, C. (2025). Prediction of seawater intrusion run-up distance based on K-means clustering and ANN model. J. Mar. Sci. Eng., 13.","DOI":"10.3390\/jmse13020377"},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"129534","DOI":"10.1016\/j.conbuildmat.2022.129534","article-title":"Compressive strength prediction of one-part alkali activated material enabled by interpretable machine learning","volume":"360","author":"Shah","year":"2022","journal-title":"Constr. Build. Mater."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"111429","DOI":"10.1016\/j.jobe.2024.111429","article-title":"Analyzing the compressive strength of one-part geopolymers using experiment and machine learning approaches","volume":"98","author":"Wei","year":"2024","journal-title":"J. Build. Eng."},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Wang, Y., Jia, Y., Wang, C., He, W., Ding, Q., Wang, F., Wang, M., and Fang, K. (2025). Interpretation of Dominant Features Governing Compressive Strength in One-Part Geopolymer. Buildings, 15.","DOI":"10.3390\/buildings15203661"},{"key":"ref_37","doi-asserted-by":"crossref","unstructured":"Chen, Q., Hu, G., and Wu, J. (2024). Prediction of the unconfined compressive strength of a one-part geopolymer-stabilized soil using deep learning methods with combined real and synthetic data. Buildings, 14.","DOI":"10.3390\/buildings14092894"},{"key":"ref_38","first-page":"e03530","article-title":"Prediction on the freeze-thaw resistance of a one-part geopolymer stabilized soil by using deep learning method","volume":"21","author":"Yao","year":"2024","journal-title":"Case Stud. Constr. Mater."},{"key":"ref_39","doi-asserted-by":"crossref","unstructured":"Zhang, J., Hu, G., Zhang, J., and Wu, J. (2026). Prediction of the Unconfined Compressive Strength of One-Part Geopolymer-Stabilized Soil Under Acidic Erosion: Comparison of Multiple Machine Learning Models. Materials, 19.","DOI":"10.3390\/ma19010209"},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"221","DOI":"10.1007\/s41062-026-02595-0","article-title":"Holistic model validation and interpretation with SHAP for machine learning models: Predicting compressive strength of fly ash geopolymer concrete using optimization algorithms and ensemble model","volume":"11","author":"Jibril","year":"2026","journal-title":"Innov. Infrastruct. Solut."},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"2061","DOI":"10.1007\/s42107-025-01602-6","article-title":"Analytical and experimental investigation on strength characteristics of one part geopolymer using machine learning models","volume":"27","author":"Harika","year":"2026","journal-title":"Asian J. Civ. Eng."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"165","DOI":"10.1007\/s40745-015-0040-1","article-title":"A comprehensive survey of clustering algorithms","volume":"2","author":"Xu","year":"2015","journal-title":"Ann. Data Sci."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"43","DOI":"10.1007\/s11222-017-9793-z","article-title":"Deep Gaussian mixture models","volume":"29","author":"Viroli","year":"2019","journal-title":"Stat. Comput."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"138","DOI":"10.1016\/j.jnoncrysol.2016.06.027","article-title":"Periodic vs. molecular cluster approaches to resolving glass structure and properties: Anorthite a case study","volume":"451","author":"Tian","year":"2016","journal-title":"J. Non-Cryst. Solids"},{"key":"ref_45","doi-asserted-by":"crossref","unstructured":"Wan, H., Wang, H., Scotney, B., and Liu, J. (2019). A novel Gaussian mixture model for classification. Proceedings of the 2019 IEEE International Conference on Systems, Man and Cybernetics (SMC), IEEE.","DOI":"10.1109\/SMC.2019.8914215"},{"key":"ref_46","first-page":"147","article-title":"Model selection for Gaussian mixture models","volume":"27","author":"Huang","year":"2017","journal-title":"Stat. Sin."},{"key":"ref_47","first-page":"100","article-title":"Experimental Study on the Compressive Strength of Slag-fly Ash Based Geopolymer Activated by Solid Sodium Silicate","volume":"40","author":"Gao","year":"2023","journal-title":"Spec. Struct."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"116891","DOI":"10.1016\/j.conbuildmat.2019.116891","article-title":"Influence of superplasticizers and retarders on the workability and strength of one-part alkali-activated fly ash\/slag binders cured at room temperature","volume":"229","author":"Oderji","year":"2019","journal-title":"Constr. Build. Mater."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"139331","DOI":"10.1016\/j.conbuildmat.2024.139331","article-title":"Microstructure and pore structure of one-part geopolymer incorporating electrolytic copper powder and graphene oxide","volume":"456","author":"Tran","year":"2024","journal-title":"Constr. Build. Mater."},{"key":"ref_50","doi-asserted-by":"crossref","first-page":"103679","DOI":"10.1016\/j.cemconcomp.2020.103679","article-title":"Properties of one-part fly ash\/slag-based binders activated by thermally-treated waste glass\/NaOH blends: A comparative study","volume":"112","author":"Samarakoon","year":"2020","journal-title":"Cem. Concr. Compos."},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"103917","DOI":"10.1016\/j.cemconcomp.2020.103917","article-title":"Effect of mixing method on the performance of alkali-activated fly ash\/slag pastes along with polycarboxylate admixture","volume":"117","author":"Alrefaei","year":"2021","journal-title":"Cem. Concr. Compos."},{"key":"ref_52","first-page":"e01269","article-title":"Experimental study of freeze\u2013thaw resistance of a one-part geopolymer paste","volume":"17","author":"Min","year":"2022","journal-title":"Case Stud. Constr. Mater."},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"117611","DOI":"10.1016\/j.conbuildmat.2019.117611","article-title":"Development of high strength one-part geopolymer mortar using sodium metasilicate","volume":"236","author":"Dong","year":"2020","journal-title":"Constr. Build. Mater."}],"container-title":["Materials"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1996-1944\/19\/14\/3108\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,27]],"date-time":"2026-07-27T05:54:00Z","timestamp":1785131640000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1996-1944\/19\/14\/3108"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,7,20]]},"references-count":53,"journal-issue":{"issue":"14","published-online":{"date-parts":[[2026,7]]}},"alternative-id":["ma19143108"],"URL":"https:\/\/doi.org\/10.3390\/ma19143108","relation":{},"ISSN":["1996-1944"],"issn-type":[{"value":"1996-1944","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,7,20]]}}}