There are many uses for recycled concrete aggregate (RCA), and this material is available in different compositions that suit certain applications such as roadway base, structural concrete or sidewalks. Purchasing this material is not a difficult process however since this material is widely used in Public Works Projects it is necessary to establish the specific requirements and be certain the use of RCA is approved by a particular jurisdiction prior to making a purchase.
With regard to availability there are literally thousands of recycle centers and batch plants throughout the U.S. where RCA can be purchased and many of these offer delivery of recycled concrete aggregate to the construction site. Locating a processing and distribution center within a convenient proximity can be accomplished by online searches or through recommendations from a reputable contractor. Since prices and services vary it would be prudent to compare prices and services in order to obtain the best value before making a purchase of the approved RCA material. This aggregate material is ordered and delivered by the cubic yard or per ton depending on the volume needed at a particular time or during a particular project phase.
The most widely used recycled concrete aggregate is sold as 1 1/2" to 2" dry processed base material and this is the ideal size for roadway construction work. The material lends itself to 95% compaction and achieving this by using RCA is far less cost intensive as opposed to the use of imported base materials that require compaction in lifts, or stages. For structural concrete the type of RCA may vary from 3/8” to 3/4” with mix design considerations that are included during the batch procedure. The exact specifications are determined by consulting the engineering specifications that pertain to the particular project. When purchasing RCA for these applications be sure to include the mix specifications.
For base material under sidewalks or commercial driveways the type of recycled concrete aggregate will most likely be ¾” with a mix proportion of 2 to1 sand. This material can be compacted to medium density that will suit pedestrian, auto and medium weight vehicle traffic. Recycled concrete base in ¼” with a mix proportion of 2 to 1 sand is also available and this size is ideal for exposed aggregate concrete finishes that are common in residential applications such as driveways and swimming pool decks.
Still another application for recycled concrete aggregate is as filler material where the over excavation of concrete footings or structural caissons has occurred. The batch design for filler applications must meet certain specifications and in some instances may require a continuous inspection while being placed. These are cost considerations that most certainly should be factored when considering the use of RCA in this way.
Again the application of recycled concrete aggregate and the batch or mix design for base or filler material must be approved. Be sure to make the proper inquiries prior to purchasing this or any RCA materials.