[TowerTalk] Steel fibre reinforced concrete (was: Pre-rebared concrete)

[Hakan Linderhed]

To answer my own question: After searching some more on the web,
I have found out that the correct term for this type of concrete
is "Steel fibre reinforced concrete". Seems fibre reinforced
concrete has been around since at least the 60's, but not really
in widespread use so far.
There is some material about it on the web, e.g. this thesis
http://www.htwk-leipzig.de/bauwesen/slowik/Diplomarbeiten/Nierbauer/concl.htm

The fibres seem to greatly reduce the risk for cracks but not sure
yet what it will do for overall strength, e.g. for use in tower bases.

Always something new to be learned...
73, Hawk SM5JBM (SM5G)

----- Original Message ----- 
From: Hakan Linderhed <sm5jbm@swipnet.se>
To: <towertalk@contesting.com>
Sent: den 4 juli 2000 12:20
Subject: [TowerTalk] Pre-rebared concrete


> 
> Hi
> 
> While pouring the base for my new tower yesterday, the concrete
> truck driver told me about a new type of "pre-rebared concrete"
> that he said is going to revolutionize the concrete industry.
> Instead of using the normal steel bars, they mix lots of small
> pieces of steel wire with the concrete, which supposedly should
> do the same job as the traditional bars.
> He showed me one "mini-bar". It was about 7 cm (3") long and
> about 1 mm (0.04") in diameter.
> 
> Has anyone any experience from this type of concrete? Does it mean
> we don't have to mess with unwieldy rebar cages any more?
> 
> Intuitively the idea seems pretty sound and I guess you could say
> that the concrete is reinforced at a "lower level" than when using
> large sized bars. But will this type of concrete hold up for 
> demanding structural applications?
> 
> The driver also mentioned that he brought some of this concrete home
> (a fringe benefit in his profession ;-) to do some stairs at his house,
> and (no surprise...) discovered that all superficial wires in the concrete
> rusted in a very short time. Since the wire bits are not connected to any
> other wires, this is probably more of an aestetical than a structural issue.
> 
> Can someone in the "concrete business" enlighten us?
> 
> 73, Hawk SM5JBM (SM5G)



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