This is only what has been done to date. Use your engineering imagination!
Aggregate base course (road base), or the untreated aggregates used as foundation for roadway pavement, is the underlying layer (under pavement surfacing) which forms a structural foundation for paving.
A cross-section of pavement would show dirt, or subgrade, as the lowest of three levels, with aggregate base course at the center and pavement (whether concrete or asphalt) at the surface.
This is the major market in the U.S. and can be mastered as the simplest and easiest use of recycled concrete. To date, it is also the most owner accepted use of recycled concrete by Departments of Transportation.
Although this site is dedicated strictly to the subject of recycled concrete aggregate, it should be mentioned here that recycled asphalt is also accepted as a usable aggregate base course or road base.
Ready Mix concrete consists of a blend of cement, sand and water. This market is in its infancy stage with few recyclers attempting this re-use strategy although confidence is gaining through the Built Green program. Above all, the recycled concrete aggregate producer must make a quality product and have secured a willing and progressive ready mix producer who already has something that works. The ready mix producer must then, in turn, make a quality end product.
Similarly, recycled concrete can be used in new asphalt pavement as a substitute for virgin aggregate. The additional asphalt cement required must be offset by the cost savings of the virgin aggregate.
Uses to date are: residential slab and foundation; walk and curb; residential street and alley; commercial slab and foundation; and concrete paving per aggregate approval.
Soil Stabilization is the incorporation of recycled aggregate, lime, or fly ash into marginal quality subgrade material used to enhance the load bearing capacity of that subgrade. The process changes the water susceptibility of subgrade thereby stabilizing the soil/subgrade.
Many times concrete aggregate can be found and reused on the same project for this purpose.
Pipe bedding: Recycled concrete can serve as a stable bed or firm foundation in which to lay underground utilities. In this scenario, recycled concrete aggregate serves as a replacement of virgin aggregate. Originally, local municipalities developed specifications based on what’s readily available in the area. This use of recycled concrete aggregate is only economical if there is a savings in the yield and transportation costs.
Landscape Materials: Recycled concrete can be used in various landscape settings. Sized concrete rubble can serve as landscape feature; an attractive support that offers different architectural texture and color while contributing to Built Green architecture. To date, recycled concrete aggregate has been used as boulder/stacked rock walls, underpass abutment structures, erosion structures, water features, retaining walls, and more.