The video below highlights a company called "Ceratech" located in Baltimore, MD (peep the inner harbor at 1:10) that have succeeded in creating a sustainable concrete alternative out of fly ash. Fly ash is a bi-product made from electrical utilities. https://www.youtube.com/watch?v=mdj_vi1_jyc
Here are a few other articles I read if anyone is interested. Their primary focus is on the environmental impacts of concrete, and not alternatives BUT the information is still interesting.
- https://www.thinkwood.com/building-better/sustainability
- http://www.greenspec.co.uk/building-design/environmental-impacts-of-concrete/
- https://en.wikipedia.org/wiki/Environmental_impact_of_concrete