October 7th, 2009

Eco-cement

by Alex Hallatt

I was reading an interesting Treehugger article about more environmentally-friendly concrete this week. Concrete from Portland cement produces a lot of carbon dioxide in its manufacture, but is very useful as a heat sink for passive solar heating. Now it looks like there is a very real alternative to Portland cement in the form of “E-crete” made from fly ash – a by-product of burning coal and something that is currently hard to get rid of. Buildings made from this stuff have lasted a very long time and the production means an 80-90% reduction in carbon emissions.

Later the same day, I read another article in CSIRO’s magazine, ECOS, about  Zeobond , based right here in Melbourne, which is a leading manufacturer of this eco-concrete. I hope they are successful in promoting this kind of building material over regular concrete.Zeobond Pty Ltd utilises waste materials of fly ash and bottom ash from power stations, blast furnace slag from iron making plants, and concrete waste to make geopolymers, which is what gives this material the large energy saving. This technology has experienced rapid growth in the last decade with an extensive range of applications particularly in the construction, architectural and refractory industries.