Thermodynamic modelling of alkali-activated materials

The Industrial Ecology Team at the University of Edinburgh is seeking an outstanding PhD candidate to apply thermodynamic modelling to alkali-activated materials.

Alkali-activated materials are a class of cementitious binders that present opportunities to achieve socioeconomic and environmental objectives, aligning with the circular economy and industrial symbiosis:
- they can exploit low quality raw materials, by-products, and wastes such as fly ash, which are otherwise challenging to utilise, to produce high performance building products;
- they usually have lower CO2 emissions than conventional cementitious binders such as hydrated Portland cement (up to ~90% reduction); and
- they can be used in specialist applications such as nuclear waste encapsulation and are useful in applications that require good fire resistance e.g. ceramics.
Because the performance of an alkali-activated material depends greatly upon its chemistry, relationships among physico-chemical properties in such materials need to be understood in order to realise their potential.

Many different raw materials may be used to produce a cementitious binder. These raw materials range from those that are rather chemically homogeneous such as limestone to those that have rather diverse/complex chemistry such as fly ash. However, there is a widespread and continued trend to produce cementitious binders using greater quantities and more diverse types of raw materials. This trend is being driven by a desire to increase material performance, beneficially use wastes/by-products, and reduce CO2 emissions. It means that the complexity and number of different binder formulations will increase in the future.

One key phase in these more diverse binders is sodium aluminosilicate (hydrate) gel. It is the major binding phase in low Ca alkali-activated materials such as those produced from fly ash and calcined clays (‘geopolymers’). Because of the prevailing trend towards materials that comprise this gel phase, there is a growing need to understand and predict its physico-chemical properties. Realising this aim would hasten the development and application of alkali-activated materials in practice, and thus to also achieve the socioeconomic and environmental aims mentioned above. Thermodynamic modelling is a general method that can be used to achieve this aim, as demonstrated by its success in other cementitious binder systems.

We are seeking a PhD candidate to develop and apply thermodynamic modelling to alkali-activated materials. In particular, the PhD candidate will generate new thermodynamic data and models for sodium aluminosilicate (hydrate) gel, and potentially also alkali-silica reaction (ASR) gel.

This is a collaborative project between the School of Engineering and School of Chemistry, and involves both modelling and experimental research. It advances upon a substantial body of work previously undertaken in the research team. We envisage that the PhD candidate will work at a world-leading level and collaborate with colleagues within and beyond the University of Edinburgh, including internationally.

Start date: Flexible – applications will be considered on a rolling and individual basis. Applicants are encouraged to apply well before February 1st 2019 to meet the deadline for School of Engineering PhD scholarships beginning in 2019.