Carbon Steel Fibers Product Profile

Products--Carbon Steel Fiber

Carbon steel fiber is used as a replacement for traditional reinforcement in various concrete applications such as: slab-on-ground, precast and shotcrete. With SUNSHINE® carbon steel fibers you can limit micro-cracking, expect excellent concrete strength and lower costs.

Excellent for major flooring projects, precast, shotcrete, highways, airports, and bridge decks.
Straight, Continuously Deformed and End Deformed Design
For matchless purity, uniformity, performance and price, no one beats the SUNSHINE® product line!

Properties of Reinforcement

　　When SUNSHINE® fibers are added to mortar, Portland cement concrete or refractory concrete, the flexural strength of the composite is increased from 25% to 100% -depending on the proportion of fibers added and the mix design. SUNSHINE~ technology actually transforms a brittle material into a more ductile one.

　　Catastrophic failure of concrete is virtually eliminated because the fibers continue supporting the load after cracking occurs. And while measured rates of improvement vary, SUNSHINE® reinforced concrete exhibits higher post-crack flexural strength, better crack resistance, improved fatigue strength, higher resistance to spalling, and higher first-crack strength. Figure 2 shows concrete flexural strengths when reinforced at various fiber proportions. Additionally, SUNSHINE® deformed fibers provide a positive mechanical bond within the concrete matrix to resist pull-out.

　　SUNSHINE fibers are available in lengths from 0.50" (13mm) to 2.0" (50mm) and aspect ratios between 40 and 60. The fibers are manufactured either straight or deformed, and conform to ASTM A-820.

　　A low carbon, cold rolled sheet steel is used to produce SUNSHINE® product for concrete applications. This steel has ultimate tensile strengths from 50 to 120 ksi (345 to 828 MPa) and has sufficient ductility actually to permit 180° bends without rupture. Various stainless steel grades are used for the reinforcement of refractory concretes. Information on these grades for high-temperature applications is available upon request. SUNSHINE® fiber has more reinforcing elements per pound of product than any of its competitors. There are nominally 21,000 3/4" and 16,000 1" straight fibers per pound, as well as 9,000 1" (254mm) deformed fibers per pound.

Improved Strength and Durability

　　SUNSHINE® reinforced concrete is a castable or sprayable composite material of hydraulic cements, fine, or fine and coarse aggregates with discrete steel fibers of rectangular cross-section randomly dispersed throughout the matrix.

　　SUNSHINE® fibers strengthen concrete by resisting tensile cracking. Fiber reinforced concrete has a higher flexural strength than that of unreinforced concrete and traditional concrete reinforced with welded wire fabric or rebar. But unlike conventional reinforcement which strengthens in one or possibly two directions - SUNSHINE' fibers reinforce isotropically, greatly improving the concrete's resistance to cracking, fragmentation, spalling and fatigue. When an unreinforced concrete beam is stressed by bending, its deflection increases in proportion with the load to a point at which failure occurs and the beam breaks apart. This is shown in Fig. 1. Note that the unreinforced beam fails at point A and a deflection of B.

　　A SUNSHINE® reinforced as in ASTM 1018 beam will sustain a greater load before the first crack occurs (point C). It will also undergo considerably more deflection before the beam breaks apart (point D). The increased deflection from point B to point D represents the toughness imparted by fiber reinforcement.

　　The load at which the first crack occurs is called the "first crack strength." The first crack strength is generally proportional to the amount of fiber in the mix and the concrete mix design.

　　Two theories have been proposed to explain the strengthening mechanism. The first proposes that as the spacing between individual fibers becomes closer, the fibers are better able to arrest the propagation of micro cracks in the concrete matrix. SUNSHINE® brand fibers contain up to 6 times more individual reinforcing elements per pound than competing brands have, minimizing space and maximizing strength.

　　The second theory holds that the strengthening mechanism of fiber reinforcement relates to the bond between the fibers and the cement. It has been shown that micro cracking of the cement matrix occurs at very small loads. SUNSHINE~ steel fibers, then, serve as small reinforcing bars extending across the cracks.

　　So as long as the bond between the fibers and cement matrix remains intact, the SUNSHINE® fibers can carry the tensile load. The surface area of the fiber is also a factor in bond strength. The rectangular cross section of SUNSHINE® fibers generate 21% more surface area than straight round fibers with the same cross-sectional area - providing greater bond strength. Bond strength can also be enhanced with the use of SUNSHINE deformed fibers, which are available from SUNSHINE International in a variety of sizes.

Shape	Material	Length(mm)	Equiv.dia.(mm)	Ratio length to diameter
Straight with minor twists	Q195 Q215 Q235	15--50	0.2--0.8	30--80
Rippled
Pressed marks
Arc

Mechanical properties

	SFRC-0	SFRC-1.0	SFRC-1.5	SFRC-2.0
Compressive strength Compressive strength(MPn)	43.6	49.8	51.2	55.3
Compressive strength Compressive strength(MPn)	100%	114.20%	117.40%	126.80%
Chop adn tension strength(MPn)	3.74	4.89	5.7	6.58
Chop adn tension strength(MPn)	100%	129.90%	152.40%	175.90%
Bending strength with initial cracks(MPn)	5.18	6.98	7.78	8.94
Bending strength with initial cracks(MPn)	100%	134.70%	150.20%	172.60%
Max.anti-deformation(MPa)	5.6	9.4	10.7	13.9
Max.anti-deformation(MPa)	100%	167.80%	191.10%	248.20%
Toughness with initial cracks(Nmm)	185.2	394.1	832.1	1161.1
Toughness with initial cracks(Nmm)	100%	212.80%	449.30%	627.00%

Prescription

Project Type	Length（mm）	Diameter（equilavent diameter mm）	Length/Diameter
Ordinarily laid steel fiber concrete	20-60	0.3-0.9	30-80
Steel fiber injected concrete	20-35	0.3-0.8	30-80
Steel fiber concrete with earthquake resistant frame joints	35-60	0.3-0.9	50-80
Steel fiber concrete railway sleeper	30-35	0.3-0.6	50-70
Laminated steel fiber concrete complex road surface	30-120	0.3-1.2	60-100

Recommendations for construction technology
1.Grade of cement should be not less than NO.425 and the ratio of water and mortar should not be more 　than 0.5

2.The length of coarse material particles should not exceed 2/3 of that of steel fiber.

3.The mass of the steel fiber in steel fiber concreate should not be less than 0.5%
　and mormally it is to be selected between 05-2.0%

4.Sea water and sea sand shall not be used for making blocking steel fiber concrete and then addition of 　chlorate is stricty prohibited.

5.Inaddition, other materials to be used together for steel fiber concreate shall
　be in accordance with the specifications of the existing standards in relation to reinforcedconcrete.

6.The viscosity of steel fiber concreate can be datermined based on the requirements of normal engineering 　projects for common concrete. The value of its subside can be 200mm less than common concrete and its 　viscosity is the same as common concrete.

7.If there is no base material unde the surface layer and the bottom layer for the shrinking seams as flat 　seams and if it is in accodance with the following conditions,then:

1.The thicknessof the surface layer and the bottom layer before the reduction is less than 130mm:2.The 　thickness of the reinforced base layer is more thant that of the
　bottom layer,then the thickness can time the reduction coefficient 0.75,but not more than 50mm.

Requirements for loading of materials
1.Steel fiber and other coarse materials are first put into a mixer and stirred for 30 seconds so that steel fiber 　shall be dispersed in the gravels to avoid agglomeration.

2.Sand and concrete is then put into a mixer for 30 second of dry stirring.

3.Water is then added into the rotating mixer with about 3 minutes of further stirring.

Packing of products:
The packing can be divided into 2 categories, either in paper cartons in an orderly manner or paper bags in an optional way based on customers’ requirement. The first is with a small volume and it is not easy to agglomerate and so it can be used by adding it directly into other materials thus reducing the cost of equipment and transportation for customers.