20.500.12556/DiRROS-23034 Carbonation of lightweight alkali-activated aggregates based on biomass fly ash effect on microstructure and leaching behavior Artificial aggregates offer a sustainable solution to large-scale waste utilization and the increasing demand for limited natural aggregates. This study extends the understanding of the production of artificial lightweight aggregates with a variable rotation speed approach based solely on biomass fly ash (BFA) alkali-activated materials (AAMs). Systematic variation of alkali content and solution density at a constant water-to-solids ratio showed that alkali concentration significantly influences granulation beyond what can be explained by water availability. The interplay between alkali activation and carbonation was investigated using different mix designs and curing conditions, as well as comparing simultaneous curing carbonation with post-cure carbonation. The results were evaluated with regard to the effects on the macro- and microstructural properties as well as on the leaching behavior. Prolonged carbonation initiated after aggregate formation resulted in premature depletion of Ca, limiting the development of C-A-S-H gels and increasing microporosity, leading to a reduction in mechanical properties. In contrast, post-curing carbonation maintained a compressive strength of over 1 MPa while still allowing carbonation benefits, resulting in compressive strengths comparable to lightweight expanded clay aggregates. Carbonation also proved to be an effective leaching mitigation strategy by stabilizing heavy metals through both physical encapsulation and chemical pH regulation. These results underline the importance of carbonation timing in high Ca AAMs and highlight lightweight aggregates as a viable pathway for BFA valorization, CO₂ sequestration and sustainable construction applications. This approach offers an alternative valorization strategy for BFA facing regulatory restrictions for direct use in cement, while contributing to carbon capture and circular economy initiatives. artificial aggregates lightweight aggregates biomass ash alkali-activated materials leaching carbonation umetni agregati lahki agregati biomasni pepel alkalijsko aktivirani materiali izluževanje karbonatizacija true false true Elsevier Angleški jezik Slovenski jezik © 2025 The Authors Neznano 2025-07-18 08:21:35 2025-07-18 08:37:48 2025-10-24 03:52:59 0000-00-00 00:00:00 2025 0 0 str. 1-18 [article no.] e05014 Vol. 23 Dec. 2025 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 2025-07-04 620.1/.2 2214-5095 10.1016/j.cscm.2025.e05014 242644483 https://www.sciencedirect.com/science/article/pii/S2214509525008125 1 75551774-639f-11f0-9bb7-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=33769 RAZ_Tesovnik_Anze_2025.pdf RAZ_Tesovnik_Anze_2025.pdf 1 7D8D32DA1562B7242BCCC8AEAA8195C1 c874f20935c5e91ff15b5aa0dfa92e911187d6484aac2f7a9a4b0f21190ec344 a395dd55-63a1-11f0-9bb7-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=33770 RAZ_Tesovnik_Anze_2025.docx RAZ_Tesovnik_Anze_2025.docx 1 71C4A6952D5B7F0DC88B2A267C790B91 e7ea28159165a91bb5ae5bde91b58382bf51f71d48411bfe6258a25474a44e71 ad10c75a-63a1-11f0-9bb7-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=33771 http://hdl.handle.net/20.500.12556/DiRROS-22660 0 b4607dd5-63a1-11f0-9bb7-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=33772 Zavod za gradbeništvo Slovenije Alkali-activated artificial aggregates 0 0 0