Characterising Wood-derived Biomass Fly Ash and Options for its Use in Concrete

TY - JOUR

T1 - Characterising Wood-derived Biomass Fly Ash and Options for its Use in Concrete

AU - Chen, Guanzuo

AU - McCarthy, Michael J

AU - Dyer, Thomas D

AU - Csetenyi, Laszlo J

N1 - © 2025 Emerald Publishing Limited

PY - 2025/11/1

Y1 - 2025/11/1

N2 - This paper investigates wood-derived biomass fly ash (BFA) and is concerned with using this as an alternative to, or in combination with, coal fly ash (CFA) as part of the cement in concrete. The four BFA samples considered were physically and chemically characterised. Their colour was within the typical range for CFA, with fineness similar to or noticeably coarser than this. They comprised various particle types and sizes, greater surface area and particle density than CFA. The BFAs had high calcium and sulfate contents and low silica, alumina and iron contents, with limited amorphous phases. Alkali and chloride levels indicate that these may need to be considered with regard to concrete durability, although Le Chatelier tests suggest little implication for volume stability. While similar early mortar strengths were obtained between BFA and CFA in some cases, by 90 days CFA gave highest strengths, suggesting little pozzolanicity for BFA. Their high alkalinity and soluble mineral levels suggest potential as a pozzolanic activator, which was then confirmed for CFA and BFA combinations with Portland cement in mortar and concrete. With further work, this approach could provide a possible route to address availability issues for the two materials.

AB - This paper investigates wood-derived biomass fly ash (BFA) and is concerned with using this as an alternative to, or in combination with, coal fly ash (CFA) as part of the cement in concrete. The four BFA samples considered were physically and chemically characterised. Their colour was within the typical range for CFA, with fineness similar to or noticeably coarser than this. They comprised various particle types and sizes, greater surface area and particle density than CFA. The BFAs had high calcium and sulfate contents and low silica, alumina and iron contents, with limited amorphous phases. Alkali and chloride levels indicate that these may need to be considered with regard to concrete durability, although Le Chatelier tests suggest little implication for volume stability. While similar early mortar strengths were obtained between BFA and CFA in some cases, by 90 days CFA gave highest strengths, suggesting little pozzolanicity for BFA. Their high alkalinity and soluble mineral levels suggest potential as a pozzolanic activator, which was then confirmed for CFA and BFA combinations with Portland cement in mortar and concrete. With further work, this approach could provide a possible route to address availability issues for the two materials.

KW - binary and ternary blends

KW - biomass fly ash

KW - material characterisation

KW - testing and evaluation

KW - UN SDG 12: Responsible consumption and production

U2 - 10.1680/jmacr.25.00146

DO - 10.1680/jmacr.25.00146

M3 - Article

SN - 0024-9831

VL - 77

SP - 1275

EP - 1288

JO - Magazine of Concrete Research

JF - Magazine of Concrete Research

IS - 21-22

ER -