This document provides information on roller compacted concrete (RCC). It defines RCC as a no-slump concrete that is compacted with vibratory rollers. RCC has similar ingredients as conventional concrete but with a drier mix that allows it to be compacted. It discusses how RCC is constructed without joints, forms, finishing, dowels or steel reinforcement, making it simple and economical. The document then discusses the uses of RCC for roads, dams, and other applications and provides details on mix design, placement, compaction, and curing of RCC.
2. Takes its name from the construction method used to build it ,It's placed
like asphalt paving equipment, and then compacted with rollers.
RCC has the same basic ingredient as conventional concrete: cement,
water, and aggregates, it's a drier mix—stiff enough to be compacted by
vibratory rollers typically.
RCC is constructed without joints. It needs neither forms nor finishing, nor
does it contain dowels or steel reinforcing These characteristics make RCC
simple, fast, and economical
Introduction
3. The largest difference between RCC mixtures and
conventional concrete mixtures is that RCC
has a higher percentage of fine aggregates, which
allows for tight packing and consolidation.
Definition
“Roller-Compacted
Concrete (RCC) is
a no-slump
concrete that is
compacted by
vibratory rollers.”
4. Roller compact concrete(RCC)
The right choice for concrete road
RCC started in the 1960
To industry switched to environmentally cleaner, economical solution
strength to withstand heavy, specialized loads.
Durability to resist freeze-thaw damage.
It is possible to achieve high quality in terms of strength, durability, and surface finish at relatively
low device and personnel costs.
The concrete can be laid very quickly – from 60 up to 120 mph. most typically in 150 or 200 mm (6
or 8-inch) thickness.
RCC is a zero slump concrete that is placed like asphalt. is then compacted directly with a vibratory
roller, mix design consistently breaks over 8,000 psi compressive strength and 800 – 900 psi flexural
strength
5. Machines and Equipments Used for RCC Paving
Testing the density of compacted concrete of the
road
6. The right choice for safe dams
Dams are a vital, RCC has three key properties that make it
uniquely suited for dams: economy, performance, and
high-speed construction, it can be used to build new
dams or to shore up old ones. It protects dams from over-
topping failure, earthquakes, and erosion.
7. Produced in a pug mill or central batch plant
Transported by dump trucks
Placed with an asphalt paver
Compacted by vibratory and pneumatic-tired
rollers
Cured with water or curing compound
Construction sequence
8. Low cost
Easy preparation
High-volume production
Speeds construction, reduces cost, Minimal labor
High strength and durability
Proven performance
Eliminates rutting and subsequent repairs
Provides high shear resistance at joints
Why use RCC ??
Benefits
9. High flexural strength (500 to 1000 psi) (3.5 Mpa to 7.0 Mpa)
High compressive strength (4,000 to 10,000 psi) (28 Mpa to 69
Mpa)
High shear strength
High density, low absorption
Low water content, low water/cement ratio
Aggregate interlock
No steel reinforcing or dowels
No forms or finishing
Hard, durable, light-colored surface
Features
11. The mix of RCC deferent from mix the conventional concrete
• A lower water content
• A lower paste content
• No air-entrainment, although some admixtures may be used to increase
workability and control set time.
• More finer aggregates
• Smaller maximum size coarse aggregate.
12. The RCC mix required curing
Curing is very important for RCC also. Since there is no bleed
water in RCC (due to much lesser water content) , the main
concern is to prevent its drying to avoid cracking resulting from
drying shrinkage & to ensure adequate strength by allowing
continuing hydration. Curing also helps in avoiding dusting of
surface, Normally surface of RCC is kept moist for 7 days.
13. How can to improve RCC
Use of Fly Ash
Provides higher strengths (50 Mpa at 56 days), and greater long term durability.
Improves workability & place-ability due to the spherical structure of Fly Ash.
Significantly reduces Alkali Aggregate Reaction (AAR), preventing cracks.
Improves Sulfate Attack Resistance, preventing expansion cracks, and loss of strength.
Reduces the Heat of Hydration (by 60%) preventing thermal cracking.
14. Chemical admixture
Air-entraining and water-reducing admixtures that contain high
volume paste
Set-retarding admixtures can extend the time up to which the
concrete lift should remain the unhardened, reducing the risk of
cold joints with subsequence lift. In RCC mixtures of dry
consistency, however, chemical admixtures show rather a limited
effectiveness.
15. Material admixture proportion
Cement:
The consolidation by a roller does not require special cements.
used in mass concrete, selecting cements with lower heat generation.
Admixtures:
The use of large amounts of mineral admixtures reduces temperature rise of concrete and costs,
and improves durability, such as Class F fly ash is the most common mineral admixture used in
dams, Class C fly ash, slag, and natural pozzolan.
aggregate:
greater than 75 mm in diameter are seldom used in RCC because it causes problems in
spreading and compacting the layer.
Usually the maximum aggregate size is limited to 38 mm
The use of material finer than 75 μm (No. 200 sieve) to reducing the volume of voids.
16. Joints
Transverse joints must be formed at an angle of 90± 5to the road
centerline.
Longitudinal joints must be formed within the zone 0.25 ± 0.15 m offset
from wheelpath or in the shoulder area a minimum of 300 mm outside
the wheelpath.
The width between fresh longitudinal joints must not exceed 5 m.
Longitudinal joints must not be located within areas likely to be under
the permanent wheel paths of the completed road pavement.