20.500.12556/DiRROS-30098 Utilisation of biomass and waste-derived ashes in the extrusion of fired clay bricks mechanical properties, microstructure and leaching behaviour With the trend towards renewable alternatives to fossil fuel sources, further uses of biomass and waste ash instead of landfilling are being explored. This study investigates the potential of fly and bottom ashes from burning wood (alone or with coal), as well as coal-co-combustion of municipal solid waste, sewage sludge, and paper sludge, for use in extruded fired bricks fired at 950 °C. The influence of ash content (0 to 15 wt% ash) and ash type (10 wt% ash) on the physical, mechanical, and microstructural properties of the fired bricks was studied. The compressive strength of the reference sample without ash was 72.6 MPa and decreased gradually with an increasing ash content. Open porosity ranged from 28% (reference, no ash) to 43% (15 wt% ash), and water absorption from 12% to 28%, reflecting the pore-forming role of the added ashes. All samples had a compressive strength above the 10 MPa limit specified in EN 772-1, except for bricks with 5 wt% paper sludge bottom ash (B4, W-PS BA). The leaching concentrations indicate that heavy metals were effectively immobilised within the ceramic structure of the fired bricks, relative to inert and non-hazardous waste limit values under EN 12457-2 test conditions. These results suggest that 5% substitution of primary raw materials with ashes may contribute to the production of bricks with reduced environmental impact and improved resource efficiency. The study provides a basis for further formulation of extruded bricks with biomass and waste-derived ashes. biomass and waste derived ashes clay extruded fired bricks ceramic-technological tests microstructure leaching pepeli sežiga biomase in odpadkov glina ekstrudirane žgane opeke keramično-tehnološki testi mikrostruktura izluževanje true false true Elsevier Angleški jezik Slovenski jezik © 2026 The Authors Neznano 2026-06-15 13:28:35 2026-06-15 13:32:29 2026-06-15 13:32:31 0000-00-00 00:00:00 2026 0 0 str. 1-21 [article no.] 116371 Vol. 127 Jun. 2026 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 2026-05-22 54 2352-7102 10.1016/j.jobe.2026.116371 280834307 https://www.sciencedirect.com/science/article/pii/S2352710226011927 1 5a70702c-68ad-11f1-aebd-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=45440 RAZ_Zibret_Lea_2026.pdf RAZ_Zibret_Lea_2026.pdf 1 8988D6C0C115FE4B33EEA7E7A1C0B3E1 be69e292-68ad-11f1-aebd-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=45441 RAZ_Zibret_Lea_2026.docx RAZ_Zibret_Lea_2026.docx 1 55D0EA58E78C8DC6D5A499FBD4D9D8FF cef6b574-68ad-11f1-aebd-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=45442 http://hdl.handle.net/20.500.12556/DiRROS-29414 0 dd3b45e2-68ad-11f1-aebd-001a4af901a5 https://dirros.openscience.si/Dokument.php?lang=slv&id=45443 Zavod za gradbeništvo Slovenije Dataset for the article Utilisation of biomass and waste-derived ashes in the extrusion of fired clay bricks: mechanical properties, microstructure and leaching behaviour 0 0 0