Recycled Concrete Aggregate (RCA) for Infrastructure Elements

2 graduate students

The objective of the proposed research is to determine the implications of using recycled concrete aggregate (RCA) in the production of new concrete. Specifically, the study will evaluate the fresh and hardened properties, durability, and structural behavior of concrete containing RCA. The expected result from this study will be guidelines for evaluating, selecting, and specifying RCA concrete. These guidelines will provide both MoDOT and design engineers with a resource to design, test, and implement RCA in transportation-related infrastructure.

Sustainability is at the forefront of our society, and concrete is the most consumed man-made material on our planet. Unfortunately, the production of concrete consumes an enormous amount of virgin materials. One area that offers significant potential for increasing the sustainability of concrete is the use of recycled concrete as aggregate for new construction. Recycled concrete is less expensive than virgin aggregate sources, and its use would remove a sizeable amount of material from landfills, turning a waste product into a viable construction material.

Concrete recycling protects natural resources and eliminates the need for disposal by using readily available concrete as an aggregate source for new concrete, including in-place recycling. However, the successful application of RCA requires a thorough understanding of its effect on the fresh and hardened properties of the resulting concrete. For instance, recycled aggregate usually has higher absorption and lower specific gravity than virgin sources. Both of these issues require adjustments during the mix design process. Concrete made with RCA can also experience increased creep, shrinkage, and permeability – as well as decreased stiffness and compressive strength – compared to concrete produced from virgin aggregate. Nonetheless, proper application of RCA can decrease the cost of transportation-related infrastructure and remove a significant amount of material from landfills, increasing the sustainability of concrete.

Relationship to other Research/Projects

This is a standalone project under the advanced materials theme of the Center for Transportation Infrastructure and Safety (CTIS) National University Transportation Center (NUTC) at Missouri S&T.

Transportation-Related Keywords

Technology Transfer Activities

The technology transfer activities will include a final research report and dissemination of the findings through a national conference via technical presentation(s) and publication(s).

Project Deliverables

Anticipated Benefits

Reduction in concrete’s carbon footprint and removal of material from the solid waste stream

Milestones