Understanding the reactivity of biomass ash from a pulverised fuel combustorCarević, Ivana (Avtor) Serdar, Marijana (Avtor) Ducman, Vilma (Avtor) Dolenec, Sabina (Avtor) Mrak, Maruša (Avtor) Štirmer, Nina (Korespondenčni avtor) biomass ashreactivityrecyclingpropertiesperspectiveThe manuscript provides long-term microstructural study on as-collected wood biomass ash (WBA) from a pulverised fuel combustor. Analytical methods, including isothermal calorimetry, X-ray powder diffraction, thermogravimetric analysis, and mercury intrusion porosimetry, were used to assess reaction kinetics, phase development, and porosity. Results show that WBA in- creases water demand due to its irregular particle morphology and high content of unburnt carbon and carbonates, causing a dilution effect that delays hydration reactions and extends the induction period. Microstructural analysis revealed significant changes in porosity, with an in- crease in pores between 0.01–0.05 μm during early hydration. As a result, early mechanical strength is reduced. Over time, the pozzolanic activity and carbonation of WBA enhance compressive strength, improving long-term performance. The study highlights the potential of WBA as a sustainable cement substitute and emphasises the need for further research to optimise its integration into concrete applications and assess its durability in various environments.Elsevier20262026-07-17 14:06:41Neznano31174UDK: 620.1/.2ISSN pri članku: 2214-5095DOI: 10.1016/j.cscm.2026.e06244COBISS_ID: 284173571sl© 2026 The Authors