There was an interesting article in SF Chronicle back in September, talking about a Stanford professor’s work on developing a greener cement. The general process involves bubbling CO2 (carbon dioxide) emissions from a power plant through seawater. This locks in CO2 into one of the ingredients of the concrete. It eliminates the need to heat limestone to 1000 degrees Celcius, which in turn eliminates a large amount of CO2 that a typical cement plant emits.

The process is still being worked on, with a test facility in California up and running. Further tests will have to be done to verify this new concrete meets building codes and other requirements. If it works, it will help the CO2 problem. The interesting bit in the article was that China is building one coal-fired power plant a week, and each plant emits enough CO2 to cancel out the benefits of every hybrid in the US. Fascinating.

In viewing the comments to the article, I also ran across another product called aerated autoclave concrete (AAC). It seems like it is lighter, stronger, and greener than traditional concrete. It is used some in the US but more overseas. So I put the link to their website below as well.

Link to Green concrete article:
Green cement

Link to AAC:
AAC