[Greenbuilding] Unconscionable Concrete Use

[Peter/Pam Martin]

At 08:13 PM 11/21/2015, John Salmen wrote:
>This is such a complex topic. Next to water concrete is the most 
>used substance in the world. Did the romans use a recipe that 
>produced less carbon dioxide. Possibly not as materials that require 
>less temperature typically release carbon dioxide at some earlier 
>point in a process (like magnesium oxide).

<snip>

According to the article at 
http://www.history.com/news/the-secrets-of-ancient-roman-concrete , 
"...Roman concrete also appears to be more sustainable to produce. To 
manufacture Portland cement, carbon is emitted by the burning fuel 
used to heat a mix of limestone and clays to 1,450 degrees Celsius 
(2,642 degrees Fahrenheit) as well as by the heated limestone 
(calcium carbonate) itself. To make their concrete, Romans used much 
less lime, and made it from limestone baked at 900 degrees Celsius 
(1,652 degrees Fahrenheit) or lower, a process that used up much less fuel".

Abstract of "Material and Elastic Properties of Al-Tobermorite in 
Ancient Roman Seawater Concrete" at 
http://onlinelibrary.wiley.com/doi/10.1111/jace.12407/abstract . 
Perhaps Monteiro's view that "that adopting materials and production 
techniques used by the ancient Romans could produce longer-lasting 
concrete that generates less carbon dioxide" is incorrect.

Peter