Results from tests at the National Ready Mixed Concrete Association’s College Park, Md., research lab support the use of crushed returned concrete as aggregate for new concrete mixes
Source: RMC Research & Education Foundation, Silver Spring, Md.
Results from tests at the National Ready Mixed Concrete Association’s College Park, Md., research lab support the use of crushed returned concrete as aggregate for new concrete mixes. An RMC Research & Education Foundation study compared the impact of crushed concrete aggregate (CCA) mixes’ fresh and hardened properties against those of specimens prepared from virgin aggregate mixes, concluding that CCA specification offers the industry potential material, processing and hauling savings up to $300 million annually. In the Crushed Returned Concrete as Aggregates for New Concrete Final Report, investigators provide ready mixed concrete producers guidance on a methodology for appropriate CCA use in concrete; the document suggests that in most applications, ungraded “as received” CCA should be permitted at up to 10 percent by weight of total aggregate.
“The call for increased recycling efforts for all industries is louder than ever. The findings show us how we can increase recycling, while saving on both materials and disposal costs,” says RMC Research & Education Foundation Chairman Dominique Calabrese (Lafarge NA). “The construction community has an obligation to examine ways to contribute to national sustainability efforts, and the CCA report demonstrates another win-win way to become more green.”
Crushed Returned Concrete as Aggregates for New Concrete can be downloaded from the Foundation’s website, www.rmc-foundation.org