Concrete Roadways - Fiber vs. Wire Mesh
Concrete Roadways - Fiber vs. Wire Mesh
(OP)
At the City i work for, we have used the fiber mesh on two subdivisions. These subdivision are both private streets, which made them good testing grounds. The older one is 1.5 years with the fiber mesh, and so far it seems to be a good product.
I just had a contractor working on another subdivision, one where the road will be PUBLIC, ask to use the fiber mesh.
Since this will be a public road, I was wondering if any one has any input on the fiber vs. mesh as to which is the better product. since our experience is only a few years old, I dont know that Im comfortable putting it into OUR roads.
From what i can see, the contractor is the only one to gain on this as the fiber is cheaper and easier to install than the wire. Id rather not save the contractor money if fiber is inferior to wire.
Im really looking for experience on this one. Has anyone had the fiber in the ground for longer than a few years? This is NE Ohio weather FYI. Thanks for the input!
I just had a contractor working on another subdivision, one where the road will be PUBLIC, ask to use the fiber mesh.
Since this will be a public road, I was wondering if any one has any input on the fiber vs. mesh as to which is the better product. since our experience is only a few years old, I dont know that Im comfortable putting it into OUR roads.
From what i can see, the contractor is the only one to gain on this as the fiber is cheaper and easier to install than the wire. Id rather not save the contractor money if fiber is inferior to wire.
Im really looking for experience on this one. Has anyone had the fiber in the ground for longer than a few years? This is NE Ohio weather FYI. Thanks for the input!





RE: Concrete Roadways - Fiber vs. Wire Mesh
http://www.eng-tips.com/viewthread.cfm?qid=126594
RE: Concrete Roadways - Fiber vs. Wire Mesh
RE: Concrete Roadways - Fiber vs. Wire Mesh
RE: Concrete Roadways - Fiber vs. Wire Mesh
I am looking for overall longevity of the product. More experience than theory is what I'm requesting.
RE: Concrete Roadways - Fiber vs. Wire Mesh
"...students of traffic are beginning to realize the false economy of mechanically controlled traffic, and hand work by trained officers will again prevail." - Wm. Phelps Eno, ca. 1928
"I'm searching for the questions, so my answers will make sense." - Stephen Brust
RE: Concrete Roadways - Fiber vs. Wire Mesh
There is some discussion of its use in this thread:
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RE: Concrete Roadways - Fiber vs. Wire Mesh
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http://www.eng-tips.com/viewthread.cfm?qid=80294
RE: Concrete Roadways - Fiber vs. Wire Mesh
Polypropylene fibers became popular in the 80's and 90's and are primarily for crack control as are the metal fibers. They differ in their ability to limit first crack propagation relative to long term crack growth.
Fiber doesn't reinforce concrete. It enhances the properties (compressive and flexural strength) that make concrete a good paving material.
For a successful concrete pavement you don't need fiber or wire mesh. You do need good control on the production and placement of the concrete. Use a concrete with a water-cement ratio of 0.45 or less, has a compressive strength of at least 4000 psi, has as large an aggregate as possible under the conditions, has good thickness control (+/- 1/4 inch), is properly consolidated, has proper control jointing, and has appropriate dowelled joints where needed.
If you want to add fiber, it won't hurt...just don't let the contractor use it at a crutch to be sloppy with the concrete control.
As for accepting something different for the public road as compared to a "private" road....don't use a double standard. Keep in mind that "private" roads might well become "public" roads in the future.
RE: Concrete Roadways - Fiber vs. Wire Mesh
RE: Concrete Roadways - Fiber vs. Wire Mesh
As also mentioned, I have only heard of it's use in the commercial and residential (slab) industry.
I would not use it in a roadway, low volume or otherwise. But, I would not use WWF in concrete pavement for a roadway either, low volume or otherwise. Rebar, in the middle of the slab is the best way to go.
RE: Concrete Roadways - Fiber vs. Wire Mesh
You can start with ACI 544.1 state of the art report by the committee. There is a series of 3 or 4 documents outlining various features of fiber concrete.
RE: Concrete Roadways - Fiber vs. Wire Mesh
When you said: "If you want to add fiber, it won't hurt...just don't let the contractor use it at a crutch to be sloppy with the concrete control."
Are you talking about using it with the fibermesh, or the fibermesh in place of the wire?
Im leaning more toward just using the wire mesh. Its tired and true, and most places still use it.
RE: Concrete Roadways - Fiber vs. Wire Mesh
I reiterate. You do not NEED either of them. Plain concrete works great for a pavement (most rigid pavements have no reinforcement). If I had to opt for either, I would choose fiber enhancement, since wire mesh is usually placed incorrectly and does no good. The fiber will at least enhance the structural properties of the concrete and will give the concrete an increase in durability, assuming they don't get sloppy with the concrete properties and mix.
Further, I'm a fan of metal fiber in concrete for pavements. It works well, offers greater property enhancement than poly fibers (the poly guys will debate this ad nauseum), but I have experience with both and have seen the differences.
Poly fiber is cheaper and more readily available, so that might be a controlling factor. Make sure the mix design is done with fiber considered...not just added as an afterthought.
Remember....good concrete is made with water, cement, aggregates and some admixtures/enhancement.....bad concrete is made of the same stuff!
RE: Concrete Roadways - Fiber vs. Wire Mesh
Well, now you have me thinking the fiber (poly) mesh might be the better option...as you are correct that the wire mesh is very rarely placed correctly.
How do the metal fibers stand up to road salt/corrosion?
RE: Concrete Roadways - Fiber vs. Wire Mesh
RE: Concrete Roadways - Fiber vs. Wire Mesh
Even for my driveway, I used 4500 psi air entrained concrete (an absolute must for my climate) plus wire mesh and fiber mesh. - Sawed control joints as soon as possible.
If I had to eliminate anything, it would be the fibermesh and not the welded wire mesh. I have a good contractor that supported and puled the mesh up as they poured/placed the concrete.
I don't think the steel fibers are very common and have been replaced by other types of fibers because they can be made in different shapes and configurations. One important thing about fibermesh is the mixing time - too little, not enough dispersal, too much, they can "ball" up and be ineffective. For exposed work the fibers sticking out of the concrete can easily be singed off with a torch.
RE: Concrete Roadways - Fiber vs. Wire Mesh
Guide to Fiber-Reinforced Shotcrete (506.1R-08)
This guide describes the technology and applications of fiber-reinforced shotcrete (FRS) using synthetic and steel fibers. "The Guide to Fiber-Reinforced Shotcrete is a completely updated resource describing the current technology and applications of fiber-reinforced shotcrete," said Larry Totten, chair of ACI Committee 506. "This document brings to the professionals using and designing fiber-reinforced shotcrete the current information for their use."
Guide for Specifying, Proportioning, and Production of Fiber-Reinforced Concrete (544.3R-08)
This guide covers specifying, proportioning, mixing, placing, and finishing of fiber-reinforced concrete (FRC). Much of the current conventional concrete practice applies to FRC. The emphasis in the guide is to describe the differences between conventional concrete and FRC and how to deal with them. This document is available for instant download in PDF format.
Publications can be ordered by calling 248-848-3800 or online at www.concrete.org.