The Use of Fiber Reinforced Concrete

[jar546]

In 1992, I started working at a brand new 1.1M square foot distribution center. I started before construction was completed and stayed on in the maintenance department. We performed a lot of renovations in the seven years I worked there, and one thing always stuck with me. I never saw one crack in the concrete floor.

Even though there were 160 electric forklifts constantly running around, I never found one single crack in the concrete floor. We had some setting issues where a forklift would run over a corner of one of the slabs, and the slab would lift up on the other end and drop back down (it was slight but made a noise), so we ended up drilling holes to grout beneath the slabs to stabilize them. The entire 1.1M square foot floor was poured with fiber-reinforced concrete. Since then, I've never encountered this type of mix spec'd out. Even in Florida, the concrete capital of the south, I have yet to see it. I've seen the benefits first hand but I am still curious why it is not used more often.

Does anyone out there see it in their area?

 

[bill1952]

Fiberglass fiber mesh? I've been reading about the stainless steel fibers used in concrete. I don't know what other materials are used.

Was there any "fuzz" on the surface? Torched off maybe?

 

[MtnArch]

Fiberglass fiber mesh? I've been reading about the stainless steel fibers used in concrete. I don't know what other materials are used.

Was there any "fuzz" on the surface? Torched off maybe?

When I was the in-house architect for a custom builder back in the early 1990's, adding the fiber mesh was all the craze and started adding it to all of our custom home slabs. It does have a peach fuzz look after curing for a day, but between normal construction activities during framing most of it was worn off, and if any was left you'd just torch it.

We found that it helped limit the width of the cracks developing, but not stopping the cracks After a year we shifted to #4's at 18"oc each way in the slab and found it did much better than the fiber mesh. If we had a client that wanted it we'd put it in, but if not it was an expense we passed by.

 

[Yankee Chronicler]

Does anyone out there see it in their area?

Yes. I recently reviewed construction documents that specified fiber-reinforced concrete.

 

[Yankee Chronicler]

Fiberglass fiber mesh? I've been reading about the stainless steel fibers used in concrete. I don't know what other materials are used.

Was there any "fuzz" on the surface? Torched off maybe?

Not "mesh" -- just bags of loose, chopped fiberglass strands mixed into the concrete.

Yes, there can be fuzz, and IIRC it is torched off. The structural engineers love the stuff, the concrete finishers hate it.

 

[bill1952]

No one with experience or anyone seen the stainless steel fiber reinforcing?

 

[jar546]

No one with experience or anyone seen the stainless steel fiber reinforcing?

Only fiberglass but I hear good things about stainless.

 

[Yankee Chronicler]

No one with experience or anyone seen the stainless steel fiber reinforcing?

I have heard of it, but all I've seen "in the wild" has been the fiberglass fibers.

 

[Msradell]

I've seen it used quite a few times with a lot of success except for one time when a concrete tank was formed using it. In that case it provided a channel for the tank to leak, I forget what it contained but it was a somewhat hazardous material the tank ended up having to be trained cleaned and the inside coated to prevent the contents from leaking!