[Image Credit: Mikko Itälahti on Flickr under a Creative Commons license]
Fly ash and bottom ash are byproducts from coal-fired power plants. Both are environmental hazards, and their disposal is toxic and costly. Small amounts of these materials can be reused in concrete production, but the rest ends up in landfills or storage lagoons. Georgia Tech assistant professor Mulalo Doyoyo is looking to solve that problem and create a greener, cement-free concrete alternative to boot!
The cement industry is responsible for 5% of the world’s CO2 emissions. Doyoyo’s cement alternative Cenocell, which is created from combining fly ash or bottom ash with organic compounds, is lighter and stronger than conventional concrete with a lower carbon footprint. Cenocell has a number of potential uses from replacing cement and some wood in construction to ultra-light heat sheilding for the aerospace industry.
Not only does this new material keep toxic ash out of the waste stream, Cenocell has strong insulating properties. That means that buildings constructed from Cenocell will be more efficient to heat and cool. They are estimating that it will cost about $50 per cubic yard, which makes it more affordable than concrete, which costs around $75 per cubic yard.
At the moment, they only have small amounts of the material to test. Doyoyo and his research team are working with a Georgia-based maker of autoclaved concrete to produce larger samples for additional testing, though. They are planning to present their findings about the material at the inception workshop of the Resource-Driven Technology Concept Center in South Africa (RETECZA) next week.