Any opinions on use of fibers in PCC pavements?

[BlastResistant]

I am told by a local sales rep that using fibers (specifically “Forta Ferro”) in roadway pavements can increase fatigue capacity of the roadway section, decrease thickness of base coarses, decrease concrete thickness, enhanced crack control etc.

Does anyone out there have experience with this? I am particularly interested in saving money by doubling the distance between transverse joints (currently located at approximately every 15 feet). If this is realistic, I figure I can save a bunch of money on the labor and material (joint fillers, sealants, dowels, etc.) by increasing the spacing of the joints. This would also translate into a reduction in long-term maintenance costs.

Any comments would be greatly appreciated.

 

[Qshake]

ACI has several good references on the use of fibers in concrete.

I doubt if the local authorities will allow for a drastic change in such elements as base thickness and joints but fibers do improve the stress resistance and improve crack control.

Regards,
Qshake

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[DarthSoilsGuy]

joint spacing is most dramatically controlled by the initial curing volume change, not seasonal conditions. i do not see how the fiber could assist this. If you are interested in expanding your joint spacing, i would look into a mix design with an expansive admixture. it is known as shrinkage-compensating concrete. I don't believe this article is on the web, but the journal "Concrete International Vol 28, No. 1 January 2006" that comes with being an ACI member has a good article if you're near an engineering library or have a current member in your company.

 

[concretemasonry]

If you are considering using shrinkage compensating additives in your concrete, take a hard look at any freeze/thaw durability durability testing on the cement or admixtures used.

Dick

 

[GeoPaveTraffic]

Adding fibers will not allow you to change the recommended joint spacing. For our pavements, 7 inches thick, we use a maximum joint spacing of 15 feet. As a consultant I would recommend a maximum spacing of 14 feet for 7 inch pavement.

Fibers will help to keep any random cracks tighter, but will not prevent them. In addition to ACI checkout ACPA at

http://www.pavement.com