# micro fiber concrete



## go do it (Nov 19, 2006)

our concrete contractor wants to use "micro fiber" in a slab that will have a polished concrete floor.

i am against the idea and insisting on the good old welded wire for reinforcement.

does anyone have any experience with micro fibers and polished floors?


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## cleveman (Dec 28, 2007)

My supplier got some smaller fiber in about 2005. I can hardly see it anymore, but it is more difficult to finish. I remember I had normal concrete once and I thought I was a helluva good finisher.

Just ask a supplier to point you to a job where the fiber stuff was used on a polished floor.


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## go do it (Nov 19, 2006)

thanks i really don't want to end up with a fuzzy floor!


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## griz (Nov 26, 2009)

If you polish it , it won't be fuzzy...

Give up on the welded wire...ends up not doing anything.

Go rebar, on a grid, on dobies.... 

Ask your Concrete Contractor and/or supplier for examples.


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## stonecutter (May 13, 2010)

It is commonly used for concrete counter tops and they are usually polished.


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## DavidC (Feb 16, 2008)

stonecutter said:


> It is commonly used for concrete counter tops and they are usually polished.


Yup, we put them in our counter tops. I see some fuzzing on the edges when the form is removed but it does grind or polish right off. Our current job is not being ground to expose the aggregate but does get a polishing and has no hair growing out of it.

The fibers we use are PVA and intended to help increase tensile strength and reduce cracking. 

I'm of the opinion that they should not be used to solely replace steel reinforcement. We use both steel mesh and fibers in our counter tops.

Good Luck
Dave


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## go do it (Nov 19, 2006)

thanks for the reply's

we will have radiant heat in the slab so we will have welded wire anyway
and now i will add micro fiber to boot

we will be adding a plasticiser to reduce the water content because we have a 6mil vapor barrier. hopefully the plasticiser will help to reduce cracks.

any more crack reducing options?


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## stonecutter (May 13, 2010)

go do it said:


> thanks for the reply's
> 
> we will have radiant heat in the slab so we will have welded wire anyway
> and now i will add micro fiber to boot
> ...


Make sure you properly prep and compact your subgrade.:thumbsup: This is probably more important than what mix design you use for the concrete because a bad base will cause the best poured slabs to crack.


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## cleveman (Dec 28, 2007)

slow cure


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## go do it (Nov 19, 2006)

10/4 on the compacted slab

i had planned to be very vigilant during this phase


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