To make the lime mix: We used raw lime slacked (wet) it added 2/3 of sand and then a week later we knocked it up and added the rest of the sand). The wall is also really heavy!
What is lime parging ? From what I understand it is a mix/process used between/ or the surface of brick, stone or concrete.
Not only is it energy intensive to make but the process actually releases CO2. However, self healing concrete is pretty interesting: http://www.asknature.org/product/cd6ff82750db9c9c7490b071e5a6b4d4
"uses microfibers in the place of coarser bits of sand and gravel that traditional cement mix uses. The fibers allow the final composite to bend with minimal fracturing and if fracturing does occur, the cracks tend to be less than 50 microns wide..."
Also there is http://www.sciencedaily.com/releases/2009/09/090929141534.htm
geopolymer concrete by using waste byproduct from coal fired power plants and help curb carbon dioxide emissions. As well as concrete without quarries. Check out the PDF attached below explaining how you can make concrete. the formula is Calcium chloride combined with Sodium hydroxide to make Sodium chloride and Calcium hydroxide into Calcium Carbonate.
I would also like to learn more about Tadelakt do you have any resources/information on the subject?
Charlie would like to know if you got his recent message about teaching a timber framing course.
All the best- N