High-volume fly-ash concrete
Concrete, a universal construction material synonymous with strength and longevity, is relatively benign in nature. However, the production of Portland cement, which is an essential constituent of concrete, leads to the release of significant amounts of carbon dioxide into the atmosphere (producing one ton of Portland cement produces about one ton of carbon dioxide).
Worldwide, cement manufacturing accounts for approximately eight percent of global carbon dioxide annual emissions. The use of concrete is expected to grow in the foreseeable future, but this growth needs to be compatible with environmental protection and sustainability.
It is widely accepted that using reclaimed industrial by-products such as fly ash, silica fume, and slag, commonly called supplementary cementing materials (SCM), can reduce the amount of cement needed to make concrete, and hence reduce its carbon dioxide signature. Using SCMs in concrete not only has the potential to reduce greenhouse gas emissions, but also to improve longterm strength and durability characteristics, and it may result in a more economical concrete than conventional Portland-cement concrete. Moreover, industrial by-products are redirected from the waste stream.
Contact: Ecosmart Foundation Inc., Vancouver, BC, Canada.
For more information, see Transmaterial: A Catalog of Materials That Redefine our Physical Environment