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 Portland Cement Association (PCA), National Ready Mixed Concrete Association (NRMCA), National Precast Concrete Association (NPCA), and theU.S. Green Concrete Council and has been publicized by several sources (e.g Nature.com, and Popular Mechanics).
The Problem[edit | edit source]
Concrete is the most used construction material in the world  and according to the World Resources Institute (WRI) 2005 report on world greenhouse gas emissions contributes to 5% of the global CO2 emmissions. In comparison iron and steel only contribute to 4% of the global CO2 emissions. This high percentage has been said to be primarily due to the vast amount of the material used in the construction industry. It is therefore essential that environmental friendly solutions are implimented to improve the sustainability of the world's buildings and infrastructure.
Solutions[edit | edit source]
Much 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.
Mix Optimization[edit | edit source]
Cement Alternatives[edit | edit source]
Ultra-High Performance Concrete (UHPC)[edit | edit source]
Geopolymer Concrete[edit | edit source]
Choosing the Right Solution[edit | edit source]
References[edit | edit source]
- Crow, James Mitchell, The concrete conundrum, Chemistry World, March 2008, 62-66
- Scrivener, Karen L. and Kirkpatrick, R. James, Innovation in use and research on cementitious material, Cement and Concrete Research, 38, 2008, 128–136