What is RCC?
RCC Definition: ACI 116 defines Roller Compacted Concrete as “concrete compacted by roller compaction”; concrete that, in its unhardened state, will support a (vibratory) roller while being compacted.
RCC is usually mixed using high-capacity continuous mixing or batching equipment, delivered with trucks or conveyors, and spread with one or more bulldozers in layers (also called lifts) prior to compaction.
RCC is used mainly for:
Dam / Mass concrete (described in ACI 207.5R) and
Pavements (described in ACI 325.10R)
Advantages & Disadvantages of RCC in Dam Structure
The main advantages of RCC are most generally:
Reduced cost and time for construction.
The RCC technology can be implemented rapidly.
RCC may not be appropriate when:
Aggregate material is not reasonably available, the foundation rock is of poor quality or not close to the surface, or where foundation conditions can lead to excessive differential settlement.
RCC in Dam Structure (principle)
The edges of the dam are formed first, by making low concrete walls on the upstream and downstream faces of the dam.
Concrete is then transported by dump trucks to the area between the walls, and spread in layer/lift (typically 300 mm thick) using bulldozers.
Rollers are then driven over the concrete to compact it down.
Mix Design of RCC
RCC is composed of:Cementitious Materials + Coarse Aggregates + Fines Aggregates + Water + Admixtures
But… mix proportioning differs from conventional concrete.
The aggregates grading and paste content are critical parts of mixture.
The paste volume must fill (or nearly fill) aggregates voids.
Design of RCC is extensively guided in ACI 207.5R.
Mix design proportioning methods:
ACI 207.5R (chapter 2.4) and ACI 211.3R extensively described the mix design proportioning methods for no slump concrete applicable for RCC