Fibre Reinforced Concrete
Fibre Reinforced Concrete
(OP)
Hi,
In the design of reinforced concrete water retaining structures somewhere in the region of 30%(depending on wall thickness, loading etc) of the reinforcement is there to restrict cracking to 0.2mm. Has anyone used or considered replacing this anti-crack reinforcement with steel fibres, to create a steel fibre/loose bar composite.
Regards
Hannis
In the design of reinforced concrete water retaining structures somewhere in the region of 30%(depending on wall thickness, loading etc) of the reinforcement is there to restrict cracking to 0.2mm. Has anyone used or considered replacing this anti-crack reinforcement with steel fibres, to create a steel fibre/loose bar composite.
Regards
Hannis






RE: Fibre Reinforced Concrete
RE: Fibre Reinforced Concrete
RE: Fibre Reinforced Concrete
RE: Fibre Reinforced Concrete
RE: Fibre Reinforced Concrete
The fiber is there to "enhance the properties of the CONCRETE", not to provide system reinforcement. In short, it will help the concrete but you still need structural reinforcement. The property enhancement of the concrete will come in both increased compressive strength and increased tensile/flexural strength. This will help reduce cracks in an otherwise good design.
I prefer steel fibers for these applications. Polypropylene fibers are not as good, in my humble opinion.
The steel will corrode at the surface, but it doesn't extend into the concrete very far and the fibers are discontinuous so there is not much chance of corrosion continuity. Besides, the alkaline concrete passivates the embedded steel, helping to resist corrosion of the embedded pieces. You can also get stainless steel fibers, but more expensive.
Production problems still exist. If the fibers are not introduced slowly into the mix, balling can still occur (the manufacturers want you to believe otherwise). This is a minor nuisance and can be easily overcome. Make sure the concrete slump is increased by the addition of a plasticizer, as the workability of fiber concrete is less than conventional concrete.
RE: Fibre Reinforced Concrete
In larger quantities, it CAN be used to increase reinforcement. At 44 pounds per yard it replaces steel. Very cool stuff, but not well known in the US.
Some great work has been done at UofMich. You might also like to see this -
http://www.kuraray.co.jp/pvaf/english/