• Welcome to the new and improved Building Code Forum. We appreciate you being here and hope that you are getting the information that you need concerning all codes of the building trades. This is a free forum to the public due to the generosity of the Sawhorses, Corporate Supporters and Supporters who have upgraded their accounts. If you would like to have improved access to the forum please upgrade to Sawhorse by first logging in then clicking here: Upgrades

The Use of Fiber Reinforced Concrete

jar546

jar546

Forum Coordinator
Joined
Oct 16, 2009
Messages
11,069
Location
Somewhere Too Hot & Humid
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?
 
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?
 
bill1952 said:
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?
Click to expand...
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.
 
bill1952 said:
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?
Click to expand...

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.
 
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!
 
You must log in or register to reply here.
Top