Benefits, Limitations and Uses of Roller Compacted Concrete – RCC
Paving contractors, highway builders, and even government agencies are turning to roller compacted concrete as the pavement of choice in greater numbers as acceptance of roller compacted concrete, also known as RCC, grows throughout the United States. . RCC offers unique qualities different from traditional concrete or asphalt that make pavement an inexpensive and quick-build candidate for many applications previously reserved for asphalt or conventional concrete.
RCC has traditionally been used for surfaces that support heavy loads at low speeds due to its relatively coarse texture, but in recent years RCC has been selected as the flooring of choice for a greater number of commercial and industrial applications. Cities like Columbus Ohio have begun using roller compacted concrete for residential streets, and Atlanta Georgia has used RCC for interstate shoulder construction. RCC is mainly used in the construction of industrial and commercial parking areas and low traffic road surfaces.
Typical RCC applications include:
- Industrial access roads and parking areas
- Shipyards and shipping ports
- Truck and freight terminals and distribution centers
- Composting and bulk product storage areas
- Aircraft parking areas
- Urban, rural and park roads
- Large commercial parking lots
- Temporary travel lanes
RCC is also being used in pavement systems for higher traffic speeds that serve as the foundation for traditional concrete or lower elevator in a two-level paving operation.
There are many benefits to using roller compacted concrete, but the main factor is that RCC can be built faster and cheaper than traditional concrete and multi-rise asphalt pavements. The RCC can be built quickly because it is typically laid with an asphalt paver equipped with a standard or high-density screed, and then compacted with rollers. Unlike conventional concrete, formwork, dowels, reinforcing steel and vibration are not used. Additionally, no transverse joints are required, however, when the project specifies that they must be present, the joints are more widely spaced than conventional concrete.
The cost savings associated with RCC are attributed not only to ease of construction, but the material also uses less Portland cement, the most expensive ingredient in conventional concrete. The specific savings associated with the use of roller compacted concrete depend on the complexity of the construction, the size of the project, and the specified mix design.
Additional Benefits of RCC – Roller Compacted Concrete
- Durability and resistance to chemical attack.
- High freeze-thaw durability even without the use of entrained air
- High strength capable of withstanding heavy repetitive loads without failure.
- Reduced cracking and shrinkage
- Rigid surface that eliminates grooves, except in areas of heavy tire chains or use of studded tires.
- Resists abrasion even under heavy traffic volume and loads
- Light colored surface reduces lighting required for parking and storage areas
- Light vehicles and cars can travel on RCC shortly after completion
While the benefits of RCC are numerous, it is important to understand that there are also some limitations to the use of roller compacted concrete. For example, the production of large quantities of RCC requires specialized equipment. While a transit mix truck can mix RCC, the mixing time is significantly longer than conventional concrete and the amount of RCC that can be mixed in the truck is reduced due to the dryness of the RCC mix. Also, the RCC surface may not be suitable for high speed traffic without diamond polishing.
Other RCC limitations
- Adjacent slabs and multiple horizontal rises should be placed within one hour to ensure a good bond unless a cold joint is planned.
- Pavement edges are more difficult to compact, causing most specifications to require 96% modified proctor density at cold joints.
- The use of additives in RCC can be greater than that of traditional concrete due to the dryness of the material.
- RCC paving in hot climates requires special attention to reduce the possibility of water loss and evaporation.
When considering the versatility of RCC, its ease of application compared to conventional concrete, and its durability compared to asphalt, it becomes clear that roller compacted concrete is a suitable substitute for paving. When considering the rising cost of oil and petroleum products such as asphalt, it becomes clear that RCC is likely to be the paving material of the future.
