Roller-compacted concrete (RCC), which takes its name from the construction method used to build it, is a concrete of zero-slump consistency in its unhardened state. It is defined as concrete compacted by roller, as per ACI 207.5R.
This would ensure an effective consolidation which is crucial for achieving satisfactory density, strength (compressive strength can be more than 60MPa), smoothness, and surface texture. The roller compacted concrete is constructed without joints, formwork, finishing, steel reinforcement, or dowels.
These characteristics make roller-compacted concrete simple, fast, and economical. Roller compacted concrete owes much of its economy to high-volume, high-speed construction methods.
Nowadays, RCC is used when strength, durability, and economy are primary needs. It is applied for construction and rehabilitation of dams, roads, airfields, parking lots, power plants, road shoulders, storage facilities, military facilities, and other industrial complexes. Depending on the desired thickness and width of the installation, the concrete can be laid very quickly – from 60 up to 120 meters per hour.
Materials, Production, and Placement
Roller compacted concrete consist of the same basic ingredient as conventional concrete: cement, water, and aggregates, such as gravel or crushed stone. However, unlike traditional concrete, the mixture is drier and adequately stiff to be compacted by vibratory roller.
The mix design of RCC usually consist of a high amount of stone, Portland cement with a replacement of fly ash, a minimal amount of sand, and of course, water to hydrate the mix.
The mixture of roller compacted concrete need to be dry enough to avoid sinking of the vibratory roller equipment, but wet enough to allow sufficient distribution of the binder mortar in concrete during the mixing and vibratory compaction operations.
Roller compacted concrete is transported, placed, and compacted using earth and rockfill construction equipment.