Comparative Assessment of Commercial and Waste-Derived Sodium Silicate Activators in PFA-GGBS Alkali-Activated Concrete.
- 1Faculty of Computing, Engineering and Science, University of South Wales, Pontypridd CF37 1DL, UK.
Abstract
The growing demand for Portland cement has intensified concerns over construction-related CO₂ emissions, driving interest in low-carbon alternatives such as alkali-activated concrete (AAC). Although AAC can substantially reduce embodied carbon, the production of commercial sodium silicate (SS), a widely used activator, remains a significant environmental burden. This study evaluates the feasibility of a waste-derived sodium silicate activator produced from silica fume (SF) and sodium hydroxide (NaOH) and compares its performance with that of a conventional commercial activator in blended f fuel ash (PFA) and ground granulated blast furnace slag (GGBS) systems. Fresh and hardened properties were assessed across a range of activator-to-binder (A/B) and SS/SH ratios, considering workability, setting time, and compressive strength requirements for structural concrete applications. Increasing the A/B ratio from 0.16 to 0.20 improved compressive strength and accelerated setting, while higher SS/SH ratios enhanced early- and later-age strength through increased soluble silica availability and gel formation. Although higher activator contents reduced workability due to increased viscosity, both commercial and SF-derived activators achieved comparable mechanical performance. The high amorphous silica content of SF was found to promote dense C-(A)-S-H gel development, while 10 M NaOH and a 24 h ambient-temperature extraction process provided sufficient silica dissolution without additional heating. These findings demonstrate the potential of SF-derived sodium silicate as a sustainable activator for producing low-carbon AAC with performance comparable to conventional systems.
Related
- Thromboelastographic Assessment of the Differential Sensitivity of Three Contact Activators to Coagulation Factor Deficiencies in Hemocell Environments
- Comparative laboratory and field assessment of commercial and nanoformulated metaldehyde baits against Monacha obstructa
- Hazelnut Husk Waste-Derived Activated Carbon for Adsorption of a Remdesivir-Containing Commercial Formulation: Equilibrium, Kinetic, and Thermodynamic Studies
- Comparative evaluation of a novel strontium silicate-based sealer on dental stem cells from human: an in vitro study.
- Comparative evaluation of shear bond strength of composite restorations and glass-incorporated restorations with calcium silicate-based cement liner: A systematic review and meta-analysis.
BibTeX
@article{ayres2026comparative,
title = {{Comparative Assessment of Commercial and Waste-Derived Sodium Silicate Activators in PFA-GGBS Alkali-Activated Concrete.}},
author = {Andrew Ayres and Jonathan Oti and John Kinuthia},
journal = {Materials (Basel, Switzerland)},
year = {2026},
month = oct,
doi = {10.3390/ma19204321},
url = {https://europepmc.org/article/MED/42941062},
note = {CC BY},
}
RIS
TY - JOUR
TI - Comparative Assessment of Commercial and Waste-Derived Sodium Silicate Activators in PFA-GGBS Alkali-Activated Concrete.
AU - Andrew Ayres
AU - Jonathan Oti
AU - John Kinuthia
PY - 2026
DA - 2026/10/14
JO - Materials (Basel, Switzerland)
DO - 10.3390/ma19204321
UR - https://europepmc.org/article/MED/42941062
AB - The growing demand for Portland cement has intensified concerns over construction-related CO₂ emissions, driving interest in low-carbon alternatives such as alkali-activated concrete (AAC). Although AAC can substantially reduce embodied carbon, the production of commercial sodium silicate (SS), a widely used activator, remains a significant environmental burden. This study evaluates the feasibility of a waste-derived sodium silicate activator produced from silica fume (SF) and sodium hydroxide (NaOH) and compares its performance with that of a conventional commercial activator in blended f fuel ash (PFA) and ground granulated blast furnace slag (GGBS) systems. Fresh and hardened properties were assessed across a range of activator-to-binder (A/B) and SS/SH ratios, considering workability, setting time, and compressive strength requirements for structural concrete applications. Increasing the A/B ratio from 0.16 to 0.20 improved compressive strength and accelerated setting, while higher SS/SH ratios enhanced early- and later-age strength through increased soluble silica availability and gel formation. Although higher activator contents reduced workability due to increased viscosity, both commercial and SF-derived activators achieved comparable mechanical performance. The high amorphous silica content of SF was found to promote dense C-(A)-S-H gel development, while 10 M NaOH and a 24 h ambient-temperature extraction process provided sufficient silica dissolution without additional heating. These findings demonstrate the potential of SF-derived sodium silicate as a sustainable activator for producing low-carbon AAC with performance comparable to conventional systems.
SN - 1996-1944
ER -