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Green Advantages of Concrete:
Æ Local
Æ Recycled
Æ Energy
► Rooftops
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Recycled Materials in Concrete Reduce CO2 Emissions and Landfill Use
The concrete industry also uses industrial waste byproducts such as fly ash (from coal combustion) and blast furnace slag (created in iron manufacture) to constitute a portion of the cement used in producing concrete. Use of such byproducts in concrete prevents 15 million metric tons a year of these waste materials from entering landfills. Utilizing these "supplemental cementitious materials" as a replacement for cement improves the strength and durability of concrete and also further reduces the CO2 embodied in concrete by as much as 70%, with typical values ranging from 15% to 40%.
Finally, when a concrete structure has served its purpose, it can be crushed for use as aggregate in new concrete or as fill or base materials for roads, sidewalks and concrete slabs. Even the reinforcing steel in concrete (which often is made from recycled materials) can be recycled and reused.
For more information, please review NRMCA's June 2008 Concrete CO2 Fact Sheet (PDF).
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ConcreteAnswers for Architects, Engineers and Developers:
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About NRMCA | Privacy Statement © National Ready Mixed Concrete Association, 2008
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Like any
manufacturing process, the production of cement
used in concrete results in the creation of
greenhouse gases, including CO2. The
U.S. cement industry has reduced CO2
emissions by 30% since 1972 and now accounts for
approximately 1.5% of U.S. emissions, well below
other sources such as heating and cooling homes
and buildings (33%), truck and auto use (27%)
and industrial operations (19%). The CO2
embodied in concrete as a finished building
product is a very small quantity considering
that cement accounts for a small proportion of
the finished product.
