We just got a nice note from www.eartharchitecture.org saying they have linked this site to their site, www.eartharchitecture.org.
www.eartharchitecture.org is a great site. Hey, go see for your self--take the time and visit our friends at www.eartharchitecture.org?
While you're there, make sure you read the article about the wall built by a group from MIT. Their wall is 70 feet long, 6 feet tall and 1.5 feet thick. They made it using a combination of 30 percent Boston Blue Clay mixed with sand and gravel.
That's 30 percent clay mixed with sand and gravel. The only mention made of cement is thus:
Dahmen and Ochsendorf, who say that a conservative estimate attributes 7 percent of CO2 emissions worldwide to the production of cement, the primary ingredient in concrete.