Applications are invited for a PhD fellowship/scholarship at Graduate School of Natural Sciences, Aarhus University, Denmark, within the Chemistry programme. The position is available from August 2026 or later.
Title:
Utilization of mineral wool waste as Supplementary Cementitious Materials in Portland cement blends
Research area and project description:
A PhD stipend is available from August 1st, 2026 at the Department of Chemistry, the Faculty of Natural Science, Aarhus University, focussing on the potential of mineral wool waste as a Supplementary Cementitious Material (SCM) in blended Portland cements.
Mineral wool is the most widely used material for isolation and soundproofing of buildings in the world. They cover glass wool and stone wool (the latter known as ‘Rockwool’ in Denmark), which are amorphous, glass-like materials that are fiberized and fixed in mats or boards by a small fraction of organic resins. In Europe, it is estimated that approx. 2.5 million tons/year mineral wool waste is produced from demolition of buildings. Although mineral wool mats can be rather easily isolated during demolition processes, this waste is hard to recycle, and most often it is deposited as landfills. In this PhD project, we wish to utilize recycled mineral wool waste to partially replace the CO2-intensive Portland cement clinker in new cement blends. This will give a two-fold gain in sustainability for the mineral and construction industries, as it will contribute to the circular utilization of mineral wool and at the same time reduce CO2 emissions of new cement-based materials.
The principal hypothesis of the PhD project is that mineral wool wastes can be used as a supplementary cementitious material (SCM) in Portland cement blends at the same Portland clinker replacement level as used today for Portland cement – fly ash blended cements. Representative samples of stone and mineral wool from Europe will be investigated in the project. The wool’s composition, microstructure, and physical properties will be explored to establish structural models for the glass and stone wools, which account for the composition of the aluminosilicate-based network structure in terms of modifier cations and for its degree of polymerization. Furthermore, their pozzolanic reactivities will be investigated and the most reactive mineral wool wastes will be tested as SCMs in blends with Portland cements. A Portland clinker replacement level of 10 – 30 wt% is targeted and optimized blend compositions will finally be developed and tested by their physical performance in concrete mortars.
Solid-state NMR spectroscopy will be a key-technique in the project to study the amorphous phases in mineral wools and blended cements. However, a range of other analytical tools will be employed in parallel. The project will be conducted in collaboration with Assoc. Prof. Juho Yliniemi from The Fibre and Particle Engineering Research Unit, University of Oulu, Finland.
Interested applicants are strongly encouraged to contact Professor Jørgen Skibsted, before applying.
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Qualifications and specific competences:
The PhD candidate should have a Master’s (3-year PhD programme) or 4-years studies (4-year PhD programme) in chemistry, nanoscience, physics, or materials science. Knowledge about inorganic materials, cement chemistry, microscale characterization tools, and NMR spectroscopy will be considered as a plus. All highly motivated candidates are encouraged to apply, regardless of their personal background. Equal consideration will be given to all qualified applicants independent of their gender, race, and cultural background.
Place of employment and place of work:
The place of employment is Aarhus University, and the place of work is Department of Chemistry, Langelandsgade 140, 8000 C Aarhus, Denmark.
Contacts:
Applicants seeking further information for this project are invited to contact: Professor Jørgen Skibsted, jskib@chem.au.dk
How to apply:
For information about application requirements and mandatory attachments, please see the Application guide. Please read the Application guide thoroughly before applying.
When ready to apply, go to https://phd.nat.au.dk/for-applicants/apply-here/ (Note, the online application system opens 1 March 2026)
Please note:
At the Faculty of Natural Science at Aarhus University, we strive to support our scientific staff in their career development. We focus on competency development and career clarification and want to make your opportunities transparent. On our website, you can find information on all types of scientific positions, as well as the entry criteria we use when assessing candidates. You can also read more about how we can assist you in your career planning and development.
Aarhus University’s ambition is to be an attractive and inspiring workplace for all and to foster a culture in which each individual has opportunities to thrive, achieve and develop. We view equality and diversity as assets, and we welcome all applicants. All interested candidates are encouraged to apply, regardless of their personal background.
