20.500.12556/DiRROS-23872 Enhancing densification of metakaolin-based geopolymers via the cold sintering process Clay-based materials typically require high-temperature processing (>900 ◦C), resulting in high energy consumption. This study explores cold sintering of metakaolin (MK) powders to achieve high mechanical strength at significantly lower processing temperatures. By applying uniaxial pressure of 400 MPa and heating to only 240 ◦ C in the presence of 15 mol/L NaOH solution, successful densification of structurally sound and dense samples with an average density of 2.16 g/cm³ and a biaxial flexural strength of ~35 MPa was achieved. This strength surpasses that of conventionally sintered MK (1470 ◦C) by ~30 %. Densification was found to be governed by synergistic mechanisms involving MK exfoliation, conformal sintering around aggregates, and the precipitation of an amorphous sodium aluminosilicate hydrate phase. Crack formation was avoided through process optimization and verified using X-ray micro-computed tomography. These findings offer new insights into the chemo- mechanical mechanisms of cold sintering and demonstrate its potential as an efficient route for producing structural materials. cold sintering metakaolin geopolymer delaminations exfoliation hladno sintranje metakaolin geopolimer delaminacije eksfoliacija true false true Elsevier Ltd Angleški jezik Slovenski jezik © 2025 The Authors Neznano 2025-10-15 07:35:31 2025-10-15 07:53:31 2025-10-24 03:55:12 0000-00-00 00:00:00 2025 0 0 str. 1-10 [article no.] 100863 Vol. 24 Dec. 2025 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 2025-10-09 621.7 2666-5395 10.1016/j.oceram.2025.100863 253167107 https://doi.org/10.1016/j.oceram.2025.100863 0 c6aa0684-a988-11f0-9bb7-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=35409 RAZ_Jabr_Abdullah_2025.pdf RAZ_Jabr_Abdullah_2025.pdf 1 7F0A08C8CF3A34928E460F10DE21264D 7cf3eb7365d5e372fe6eb95e981589ad793eda5d165f25eda6ec23933b9b6b09 14bb8fde-a98b-11f0-9bb7-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=35410 Zavod za gradbeništvo Slovenije 0 0 0