Recycled Concrete Aggregate (RCA) is a product in which steel and other debris is separated out from the concrete and the concrete is crushed for use as road base, fill, landscaping material, soil stabilization, and in some situations as aggregate for ready-mixed concrete and asphalt.
Pervious concrete. Pervious concrete is used to manage stormwater runoff, and in some cases eliminates the need for retention ponds. By allowing rain and snow melt to soak into the ground, pervious concrete helps recharge aquifers.
There are many unique applications for pervious concrete happening throughout the industry, including paving for residential streets and decorative applications. At the University of Tennessee at Chattanooga, pervious concrete is being used for water harvesting; water from a pervious parking lot is diverted to a cistern, then used to water the athletic field.
In the field, concrete contractors and ready mix suppliers have worked side-by-side in moving the pervious market forward. The NRMCA has already certified more than 3,500 contractors through its pervious certification program. The RMC Research & Education Foundation's study from December 2007, "Pervious Concrete Pavement: Field Performance Investigation on Parking Lot and Roadway Pavements," laid to rest many of the concerns people had with pervious concrete in freeze/thaw environments and made pervious concrete a national product. The NRMCA also offers contractors pervious pavement promotional brochures and an educational seminar on the topic.
Albedo, or solar reflectance. In sustainable building situations, there are benefits to paving parking lots, sidewalks and other impervious areas with high albedo materials, or materials with a high level of solar reflectance. Designers often choose concrete or pervious concrete over asphalt in these situations because concrete's higher light reflectance reduces the heat island effect.