The UK Quality Ash Association (UKQAA) – the representative organisation for the producers and users of coal ash in the UK – has launched a new flyash research project, in partnership with the Concrete Technology Unit (CTU) at the University of Dundee, Scotland, to investigate whether stockpiled flyash could be recovered and used as a pozzolana in concrete and cement.
The research programme – the first of its kind in recent years – will be significant for the construction sector. With demand on the rise for high quality flyash, the research could help give the sector access to material previously thought unusable. It is believed that there is as much as 50 million t of flyash in storage at coal-fired power stations across the UK, but until now there has been no study into the amount of ash that could be recovered for use in construction.
Driven by the UKQAA, the study will first establish an accurate estimate of the amount of stockpiled ash in the UK. Samples from across UK ash fields will be collected and tested in laboratories to assess their performance as pozzolanas, used as a partial cement replacement in concrete. The CTU will then work with the UKQAA to develop a process route to transform stockpiled ash into flyash, which meets the specification of EN 450, the recognised standard for the use of flyash in cement and concrete.
The benefits are potentially huge. Flyash sourced directly from power stations is already widely used in the construction sector, from bricks and blocks to ready-mixed concrete in major engineering projects. If successful, the research could significantly boost supplies and allow the industry to make greater use of a valuable secondary material – cutting carbon dioxide emissions and reducing the need for primary raw materials in cement and concrete production.
Dr Robert Carroll, Technical Director at the UKQAA, said: “This is a really exciting opportunity. Flyash demand continues to rise to keep pace with a growing construction sector, but availability is dependent on our use of coal power. Unlocking the potential of stockpiled ash in ashfields across the UK could increase supply, meet construction demand and exploit an otherwise underused material.”
“Flyash is a vital construction material and key constituent of sustainable concrete products. As a result, there is a well established flyash supply chain in the UK, with a consistent demand for raw material. With up to 50 million t of flyash stockpiled in the UK, this project has the potential to not only sustain a well established ash market but also create new ones,” he added.
The flagship project is jointly funded by the UKQAA and the Engineering and Physical Sciences Research Council, and is expected to run for three and a half years. Based in the laboratories of the University of Dundee, the research programme is being lead by Dr Michael McCarthy, with a team including PhD research student Thomas Hope, who will work in close partnership with the UKQAA and its members.
Dr McCarthy added: “We have carried out research on flyash in construction for more than 25 years and the project, investigating recovery and processing of stockpile material, is in keeping with much of our other work concerned with broadening the scope of its use. We look forward to our role in this important area”
Read the article online at: https://www.worldcement.com/europe-cis/10122014/ukqaa-begins-flyash-research-project-985/