Study Finds Advantages of Recycled Concrete Aggregate

Pile of rubble

How does recycled concrete aggregate compare to traditional virgin limestone as a base course? A project in Ohio was put together specifically to pit the two against each other to see which performs best. John Dingledein and Elizabeth Olenbush explored the specifics of the study for C&D World. According to the findings, blended recycled base course is at least as effective as virgin limestone and is likely to become stronger over time.The project used a blend of recycled concrete aggregate and foundry sand for half of its needs, and used a control of traditional limestone on the rest. Specifically, the recycled aggregate blend used 16.5-percent foundry sand and 83.5-percent recycled concrete aggregate. They found that the recycled base met the Ohio Department of Transportation’s specifications better than the limestone.Researchers also found that, based on Falling Weight Deflectometer and Resilient Modulus testing, the recycled blend will gain strength over time. This estimate was found to be consistent with the experience of multiple commercial contractors using recycled aggregate.While the recycled concrete blend allowed less water filtration throughout the testing, neither base allowed a significant amount and neither exceeded the minimum requirements for roadway base specifications.Perhaps the most telling evidence is the recommendations of those involved in the project. They clearly state that to improve the strength and durability of roadways, should be using the blend of local foundry sand and recycled concrete aggregate.While this team only experimented with aggregate blends containing up to 25-percent foundry sand, they believe that their blends remained on the conservative side. More sand is believed to be able to be used without a significant loss in performance. More controlled processing of the recycled concrete is even suspected to produce an even better blended aggregate product.At Demolition Technologies, we’re experienced in screening, crushing and blending of recycled concrete. We even feature on-site concrete crushing for many projects. Call us to learn more about our capabilities on demolition jobs in the Midwest and beyond.