FIBER REINFORCED CONCRETE

(FRC)

Created and presented by:Dilip singhKartik

What is fiber reinforced concrete

A concrete consisting of, cement, water, fine and coarse aggregate, along with discontinuous fibers.

Types of fibers

Types of fibers include Steel Plastic

Polyester, Polypropylene, Polyethylene Glass Natural materials

Wood cellulose, Bamboo, Elephant grass

All are available is different shapes sizes and materials

Types of fibers

Steel Shapes

Steel fibers are adhered together before mixing and separate while mixing to ensure uniform distribution

Advantages of using fiber reinforced concrete versus plain

concrete

Improves toughness of concrete Flexural strength is improved by up to 30%

by decreasing the propagation of cracks Improves tensile strength More economical than steel reinforcement Less prone to corrosion Gives an alternative way to reinforce

concrete other then traditional steel rebar

PCC

FRC

Corrosion

Unlike rebar there is not galvanic cell created in the fibers

No anodic/cathodic reaction pH level of concert protects steel fibers

from corrosion

Applications

Applications include: Pipes Tilt-up Panels Shotcrete Slabs Counters tops Bath tubs Tiles

Properties

Durability Made with a high content of cement and

low water to cement ratio When properly compacted and cured,

concrete with steel fibers is very durable Workability

Affects workability Compensate by adding superplasticizers

Properties

Compressive behavior of steel FRC Keeps integrity after failure Strength slightly enhanced

Tensile behavior increase tensile strength

Has little effect on the modulus of elasticity, drying shrinkage, and creep

Production

Production is guided and controlled mainly by the American Concrete Institute, ASTM, and various building codes

Production involves 5 Steps1. Determine typical Uses and Specifying

FRC2. Materials3. Mixture Proportioning4. Batching, Mixing, Delivery and Sampling5. Placing and Finishing

Summary

Fiber reinforced concrete is one of the oldest methods for reinforcing concrete

The main purpose of fiber reinforcement is to increases its structural integrity and improve flexural behavior

There are many different types of fiber that can be used for concrete reinforcement.

Is an economical way to reinforced concrete compared to regular steel.

Roller-compacted concrete

Roller-compacted concrete (RCC) or rolled concrete is a special blend of concrete that has essentially the same ingredients as conventional concrete but in different ratios, and increasingly with partial substitution of fly ash for Portland cement.

The produced mix is drier and essentially has no slump. RCC is placed in a manner similar to paving; the material is delivered by dump trucks or conveyors, spread by small bulldozers or specially modified asphalt pavers, and then compacted by vibratory rollers .

 RCC was used for backfill, sub-base and concrete pavement construction, but increasingly it has been used to build concrete gravity dams because the low cement content and use of fly ash cause less heat to be generated while curing than do conventional mass concrete placements

Roller-compacted concrete has many time and cost benefits over conventional mass concrete dams; these include higher rates of concrete placement, lower material costs and lower costs associated with post-cooling and formwork.

For dam applications

RCC sections are built lift-by-lift in successive horizontal layers resulting in a downstream slope that resembles a concrete staircase. Once a layer is placed, it can immediately support the earth-moving equipment to place the next layer. After RCC is deposited on the lift surface, small dozers typically spread it in one-foot-thick (300mm) layers

History

The first RCC dam built in the USA was the Willow Creek Dam in Oregon of the Columbia River. It was constructed by the Army Corps of Engineers between November 1981 and February 1983. Construction proceeded well, within a fast schedule and under budget (estimated $50 million, actual $35 million)

References

www.Google.com www.Wikipedia.org