Concrete is ubiquitous in our world, as is concern about carbon emissions. The creation of concrete is a major source of carbon emissions, because the calcium-based substances that make it up are heated at high temperatures to form the cement.
But scientists at MIT may have found a way to decrease the carbon emissions that result from concrete production: reducing the ratio of calcium to the silicate-rich clay.
Normally, concrete is made by mixing gravel, water, sand, and cement, Gizmag reports. The cement is produced by heating calcium-rich materials (e.g., limestone) at temperatures up to 2,732 F, and researchers say that this part of the process produces the majority of the carbon emissions.
The MIT research team examined the makeup of the concrete, and found that a calcium to silica ratio of 1.5 is the optimal mix for reducing emissions and producing quality concrete. In the industry, these ratios can vary from 1.2 to 2.2, though 1.7 is the cement production standard. Changing the standard ratio to 1.5, researchers say, could reduce carbon emissions by as much as 60%.
This mix of concrete was also shown to have a higher resistance to fractures. According to Gizmag, the researchers claim that "this is due to the molecular structure transforming from a tightly ordered crystalline to a disordered glassy structure." Regardless of the reason why, the 1.5 ratio concrete has twice the mechanical resistance to fractures of normal cement.
Because the analysis of this concrete mix was carried out on a molecular level, it remains to be seen whether or not these results will remain the same in engineering-scale applications. This research was published in the journal Nature Communications.
Related Stories
| May 15, 2012
One World Trade Center goes to new height of sustainability
One of the biggest challenges in developing this concrete mixture was meeting the Port Authority of New York/New Jersey’s strict requirement for the replacement of cement.
| May 14, 2012
Adrian Smith + Gordon Gill Architecture design Seoul’s Dancing Dragons
Supertall two-tower complex located in Seoul’s Yongsan International Business District.
| May 11, 2012
CRSI appoints Brace chairman
Stevens also elected to board of directors and vice-chair.
| May 8, 2012
Gensler & J.C. Anderson team for pro bono high school project in Chicago
City Year representatives came to Gensler for their assistance in the transformation of the organization’s offices within Orr Academy High School, which also serve as an academic and social gathering space for students and corps members.
| May 8, 2012
Morgan/Harbour completes three projects at Columbia Centre
Projects completed on behalf of property owner, White Oak Realty Partners, LLC, Pearlmark Realty Partners, LLC and Angelo Gordon & Co.
| May 7, 2012
2012 BUILDING TEAM AWARDS: TD Ameritrade Park
The new stadium for the College World Series in Omaha combines big-league amenities within a traditional minor league atmosphere.
| May 3, 2012
Ground broken for $94 million hospital expansion at Scripps Encinitas
New facility to more than double emergency department size, boost inpatient beds by 43%.
| May 2, 2012
Building Team completes two additions at UCLA
New student housing buildings are part of UCLA’s Northwest Campus Student Housing In-Fill Project.
| May 1, 2012
Construction is underway on MLK ambulatory care center in L.A.
Featuring a variety of sustainable features, the new facility is designed to achieve LEED Gold Certification.
| Apr 26, 2012
Orange County, Fla. high school receives NAIOP “Public Development of the Year” award
School replacement designed by SchenkelShultz Architecture and constructed by Williams Co.