Novel Methods for Manufacturing Pollutant Reducing Concrete
Physical Sciences : Civil Engineering
Available for licensing
- Maria Juenger, Ph.D. , Civil, Architectural and Environmental Engineering
- Sarah Taylor-Lange , Civil, Architectural and Environmental Engineering
- Kyle Riding, Ph.D. , Kansas State University Research Foundation
Research indicates carbon dioxide emissions from human activity have been a major cause of the increase in average temperature recorded around the world since the beginning of the industrial revolution. So called "greenhouse gases", gases that when exposed to solar energy create smog and effectively trap heat in the lower levels of the atmosphere, are an area of concern in industrialized countries who look to reduce and potentially eliminate such emissions in order to reverse this alarming trend.
Interestingly, one industrial activity is responsible for 3% to 5% of the human activity generated CO2 emissions in the world, cement manufacturing. Portland cement provides the cementitious material component in concrete. Most portland cement consists of blends of naturally occurring cementitious materials, like calcined shale, metakaolin clay or diatomaceous earth. Other additives are used to reduce overall cost or enhance finished concrete performance, like fly ash from coal-fired power plants, or ground-granulated blast furnace slag from steel manufacture.
The manufacture of portland cement is an energy intensive process requiring the heating of the blended components to temperatures as high as 800°C. Heating of these high volume furnaces generates a great deal of CO2, approximately 1 ton CO2 per 2 tons cement.
Collaborative researchers from The University of Texas at Austin and Kansas State University have developed a process for manufacturing cementitious materials requiring less heat, thereby saving on fuel consumption and producing less CO2in the process. An added advantage, the process incorporates a waste material which further enhances its "green" aspects.
A great deal of research has been conducted around identification of alternative materials to provide added strength, reduced cure time, and other physical property enhancements to concrete admixtures. Typical materials tested provide better performance in some areas but less than optimal in others.
This technology appears to provide benefits to finished concrete strength even though it is manufactured at temperatures nearly 20% lower than typical processes. The dramatic reduction in process temperature effectively reduces fuel requirement, hence CO2 emissions from the process.
- Lower temperature operation = lower fuel requirement = lower CO2 emissions
- Incorporates waste material generated by steel mills and aluminum processing that typically ends up in landfills.
Cement is an essential component in the building industry used in formulating concrete. The cement industry is responsible for 3.4% of the global anthropogenic (human activity related) CO2 emissions, of which 54% comes from chemical processing and 46% from burning fossil fuels for generating the thermal energy needed in the manufacturing process
Proof of concept