Reformix selected to Present at Concrete 2025 on the Industrial Standardisation of Geopolymer Binder Activator Preparation*

Reformix presented work at Concrete 2025 – Concrete Solutions for a Sustainable Future, held in Adelaide from 7–10 September 2025. Our paper, “Optimising Geopolymer Activator Preparation: Thermophysical Insights from a Fly Ash Case Study Towards Process Standardisation” addressed a largely overlooked variable in geopolymer technology: Activator solution preparation.

Challenging the 24-Hour Convention

Many geopolymer studies adopt arbitrary 24-hour activator equilibration periods before mixing. Our thermophysical modelling and calorimetry show this is unnecessary with experimentally validated methods demonstrating that:

• NaOH(aq) systems reach thermodynamic stability in under 30 seconds.

• NaOH(s) systems stabilise within approximately 1 minute.

When applied to Western Australian fly ash systems, activator mixing periods can be reduced from 24 hours to a staggeringly low 0.5 hours resulting in:

• Increased compressive strength by an average of 12.1 ± 3.5 MPa

• Produced a maximum strength improvement of 28.45 ± 1.1 MPa

Why This Matters

Abstract of the submitted paper, read more at https://www.researchgate.net/publication/397949631_Optimising_Geopolymer_Activator_Preparation_Thermophysical_Insights_from_a_Fly_Ash_Case_Study_Towards_Process_Standardisation

At laboratory scale, 24-hour equilibration is inconvenient, at industrial scale, it is a barrier.

Optimising activator energetics improves:

• Flowability

• Wetting behaviour

• Mixing efficiency

• Quality control

• Process scalability

Standardising activator preparation is not a minor procedural refinement, it is a pathway toward industrialising geopolymer systems.

Industry Context

Concrete 2025 made one thing clear = industry is actively pursuing high SCM and alternative binder systems. Several sessions covered high-volume replacement, calcined clays, carbon mineralisation, geopolymer and alkali-activated systems. However, reliability and standardisation remain central concerns. Activators are often treated as a secondary variable. They are not. If activator preparation is inconsistent, binder performance will be inconsistent. Concrete 2025 reinforced that the future of low-carbon concrete depends not only on new materials, but on engineering control of the systems that produce them.

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*Citation: R. Skane, E. Jamieson, P. A. Schneider, H. Gildenhuys, J. Allery, X. Sun and W. D. Rickard, “Optimising Geopolymer Activator Preparation: Thermophysical Insights from a Fly Ash Case Study Towards Process Standardisation,” in Concrete 2025: The 32nd Biennial Conference of the Concrete Institute of Australia, Adelaide, 2025.