{"id":49324,"key":"Concrete:Gray_to_Green","title":"Concrete:Gray to Green","latest":{"id":1223974,"timestamp":"2026-01-08T23:48:59Z"},"content_model":"wikitext","license":{"url":"https://www.appropedia.org/Appropedia:Copyrights","title":"CC-BY-SA-4.0"},"source":"The Concrete Gray to Green movement is a recent development with the goal to reduce the evironmental impact of concrete and other cement based construction materials. It has become a topic of high interest for industry leaders, such as the [http://www.cement.org/homes/brief12.asp Portland Cement Association (PCA)], [http://web.archive.org/web/20160609035709/http://www.nrmca.org/GreenConcrete/ National Ready Mixed Concrete Association (NRMCA)], [http://precast.org/2011/09/from-gray-to-green/ National Precast Concrete Association (NPCA)], and the[http://web.archive.org/web/20150322065709/http://usgreenconcretecouncil.com/editorial.htm U.S. Green Concrete Council] and has been publicized by several sources (e.g [http://www.nature.com/news/green-cement-concrete-solutions-1.12460 Nature.com], and [http://www.popularmechanics.com/home/how-to-plans/masonry/gray-to-green-how-to-make-cleaner-concrete#slide-3 Popular Mechanics]).\n\n== The Problem ==\n\nConcrete is the most used construction material in the world<ref name=\"Crow\">Crow, James Mitchell, The concrete conundrum, Chemistry World, March 2008, 62-66</ref> and according to the [http://web.archive.org/web/20130629143441/http://www.wri.org/chart/world-greenhouse-gas-emissions-2005 World Resources Institute (WRI)] 2005 report on world greenhouse gas emissions contributes to 5% of the global CO<sub>2</sub> emmissions. In comparison iron and steel only contribute to 4% of the global CO<sub>2</sub> emissions. This high percentage has been said to be primarily due to the vast amount of the material used in the construction industry.<ref name=\"Scrivener\">Scrivener, Karen L. and Kirkpatrick, R. James, Innovation in use and research on cementitious material, Cement and Concrete Research, 38, 2008, 128–136</ref> It is therefore essential that environmental friendly solutions are implimented to improve the sustainability of the world's buildings and infrastructure.\n\n== Solutions ==\n\nMuch of the research and education consists of mix optimization and using partial replacment alternatives to portland cement, however, other solutions also exist. Two of which are ultra-high performance concrete (UHPC) and geopolymer cement concrete.\n\n=== Mix Optimization ===\n\n=== Cement Alternatives ===\n\n=== Ultra-High Performance Concrete (UHPC) ===\n\n=== Geopolymer Concrete ===\n\n=== Choosing the Right Solution ===\n\n== References ==\n\n<references />\n\n== Links ==\n\n[http://www.concrete-greenbuilding.com/ Concrete Green Building]\n\n{{Page data\n| license = CC-BY-SA-3.0\n| description = Concrete Gray to Green reduces cement’s footprint. Appropedia explores new materials transforming sustainable construction.\n}}\n\n[[Category:Concrete]]"}