Wood biomass ash as a clinker substitute in advancing next-generation blended cement: Croatian case study.

This research investigates the use of wood biomass ash (WBA) as a supplementary cementitious material (SCM) in blended cement formulations containing 6 and 12 wt% of bottom WBA. Motivated by the need to advance low-carbon cement production, reduce reliance on imported materials, and incorporate waste management strategies, the study explores sustainable pathways for cement manufacturing. Experimental results show that the 6 wt% WBA blend (BLEND BC-II) achieves a compressive strength of 59.3 MPa after 28 days, surpassing the reference CEM II, whereas the 12 wt% WBA blend (BLEND BC-I) also delivers favourable mechanical and durability performance, including a chloride diffusion coefficient of 15.85 × 10⁻¹² m²/s, capillary absorption of 0.68 g/m²·h¹/², and gas permeability of 0.50 × 10⁻¹⁶ m². Volume stability tests of the 12 wt% WBA blend confirm that autogenous deformations remain below − 0.017 mm/m after 90 days, indicating effective mitigation of shrinkage and reliable dimensional stability. When combined with other SCMs, WBA further improves long-term mechanical performance. Despite challenges related to compositional variability and infrastructure requirements, WBA incorporation can reduce environmental impact and support low-carbon cement production. Achieving net-zero emissions extends beyond quantitative targets, requiring the restoration of balance between resource use, material efficiency, and environmental sustainability. These findings demonstrate that WBA is a viable SCM, advancing sustainable and resilient cement manufacturing.