# FRP Rebar



## linnrg (Oct 9, 2018)

What are people out there seeing in the use of this fiber Rebar?  I see that ACI has an actual guideline on this.

440.1R-06: Guide for the Design and Construction of Structural Concrete Reinforced with FRP Bars


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## Francis Vineyard (Oct 9, 2018)

Contractors want to use it to cut cost, but to my recollection it's approved for nonstructural applications.


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## linnrg (Oct 9, 2018)

looks like the latest is 440.1R15 and it costs a mere $108.50

from the site:

*DESCRIPTION*
Fiber-reinforced polymer (FRP) materials have emerged as an alternative for producing reinforcing bars for concrete structures. Fiber-reinforced polymer reinforcing bars offer advantages over steel reinforcement because they are noncorrosive. Some FRP bars are nonconductive as well. Due to other differences in the physical and mechanical behavior of FRP materials versus steel, unique guidance on the engineering and construction of concrete structures reinforced with FRP bars is necessary. Other countries and regions, such as Japan, Canada, and Europe have established design and construction guidelines specifically for the use of FRP bars as concrete reinforcement. This guide offers general information on the history and use of FRP reinforcement, a description of the unique material properties of FRP, and guidelines for the design and construction of structural concrete members reinforced with FRP bars. This guide is based on the knowledge gained from worldwide experimental research, analytical work, and field applications of FRP reinforcement.


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## ICE (Oct 9, 2018)

The internet says that FRP has higher tensile strength than steel.  I have not encountered it in use.


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## Francis Vineyard (Oct 10, 2018)

Compare apples to apples relatively speaking with comparable qualities of stainless to FRB.
Had separate request for large slabs on ground and parking garage, don't know why the RDP wouldn't approve it.


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## Francis Vineyard (Oct 10, 2018)

What do the ACI guidelines say?


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## mark handler (Oct 10, 2018)

In CA Caltrans has been using sheets of Fiber-reinforced polymer (FRP) to reinforce and retrofit freeway columns for years. 

I another life, the company I worked for,  specified it for *high corrosive* military locations. Guam, Hawaii, and the Philippines.

Simpson Strong-Tie’s has gotten in the market,
https://www.strongtie.com/products/rps/css/frp-fiber-reinforced-polymer


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## mark handler (Oct 10, 2018)

FRP Rebar Market is set to exceed $1.25bn by 2024
http://basalt.today/2017/06/11098/


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## Francis Vineyard (Oct 10, 2018)

Now I recollect we have an engineer here that uses the fabric applied to basement foundation walls for repairs. Interesting concept.


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## ADAguy (Oct 10, 2018)

What is its life expectancy if left exposed, what of stretch? Brittleness?


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## Builder Bob (Oct 10, 2018)

The only application for FRp rebar I have seen used and inspected was for a agricultural scale at a state agency that could not have any electrical interference that would cause calibration issues for the scale.


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## linnrg (Oct 10, 2018)

if this is non-conductive and non corrosive I would think the people in the swimming pool world would be seeing it right away.
Advertisement says it could last way longer than other products.

By the way this is available at all of your local supply stores.


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## mark handler (Oct 10, 2018)

https://www.americanfiberglassrebar.com/default.aspx
USE FRP REBAR
Concrete Susceptible to Corrosion 
•   Waste Water Treatment Facilities
•   Swimming Pools
Tunneling & Mining 
•   Sequential Excavation or NATM Tunneling
•   Deep Foundation Tunnel Boring Machine “Soft-Eye” Opening  for Launch & Reception
•   Temporary Reinforcement
•   Rock Bolts
Building & Historic Preservation 
•   Historic Preservation - Restoration & Pinning of Stone Elements
•   Architecture Concrete Elements
•   Slabs
Exposure of Concrete to De-Icing Chlorides 
•   Bridges & Railings
•   Median Barriers
•   Parking Structures
•   Approach Slabs
•   Continuously Reinforced Concrete Paving
•   Precast Elements
•   Salt Storage Facilities
Masonry Strengthening 
•   Seismic, Wind or Blast Strengthening of Unreinforced Masonry
•   Strengthening for “Event Loading” of Clay & Concrete Masonry
Exposure of Concrete to Marine Chlorides 
•   Coastal Construction exposed to Salt Spray
•   Sea Walls, Wharfs & Dry Docks
•   Desalinization Intakes
•   Port Aprons
Exposure of Concrete to High Voltages & Electromagnetic Fields 
•   Light & Heavy Rail
•   High Voltage Substations
•   Radio Frequency Sensitive Areas
•   Cable Ducts & Banks
•   Hospital MRI Areas
•   Aluminum Smelters & Steel Mills
•   High Speed Highway Tolling Zones
•   Airport Radio & Compass Calibration Pads

American Fiberglass Rebar products
(702) 567-2514 Direct or (885) 6409861 Toll Free. Email  sales@americanrebar.com

*American Concrete Institute (ACI)*

*440.1R-06:* Guide for the Design and Construction of Structural Concrete Reinforced with FRP Bars

*440.5-08:* Specification for Construction with Fiber-Reinforced Polymer Reinforcing Bars

*440.6-08:* Specification for Carbon and Glass Fiber-Reinforced Polymer Bar Materials for Concrete Reinforcement

*440.3R-12:* Guide Test Methods for Fiber-Reinforced Polymer (FRP) Composites for Reinforcing or Strengthening Concrete Masonry Structures

*440.2R-08:* Guide for the Design and Construction of Externally Bonded FRP Systems for Strengthening Concrete Structures

*440.7R-10:* Guide for the Design and Construction of Externally Bonded Fiber-Reinforced Polymer Systems for Strengthening Unreinforced Masonry Structures


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## Mark K (Oct 10, 2018)

FRP rebar has not been adopted into the code and thus if proposed must be considered as an alternate means of construction.

FRP rebar does not have the ductility that steel rebar has and thus would be inappropriate for some applications.  A significant amount of FRP  is used to mitigate problems with existing masonry or concrete members and while it may improve the performance of these members my sense is that these reinforced members will not perform as well as new fully compliant members would.


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## mark handler (Oct 10, 2018)

In the code or not,  Fiber-reinforced polymer (FRP) is the future.


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## Msradell (Oct 10, 2018)

I've also done some reading on FRP Bars and a lot of the advantages are offset by some of the disadvantages.  It's very susceptible to environmental factors such as UV light etc. and its strength will deteriorate if left exposed to direct sunlight.  In addition any damage to the services will also reduce his strength.  Most of the withers are I read also say that you have to leave it on pallets instead of laying it directly on the ground which in most jobsites would be a huge disadvantage.  Any material that records bends has to be bent before it's fully cured, cured Bars cannot be bent.

I can see where it may be advantageous in some situations but it doesn't sound like it's something it will take over huge portions of the field until some big improvements are made to it.


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## mark handler (Oct 11, 2018)

Msradell said:


> I've also done some reading on FRP Bars and a lot of the advantages are offset by some of the disadvantages.  It's very susceptible to environmental factors such as UV light etc. and its strength will deteriorate if left exposed to direct sunlight.  In addition any damage to the services will also reduce his strength.  Most of the withers are I read also say that you have to leave it on pallets instead of laying it directly on the ground which in most jobsites would be a huge disadvantage.  Any material that records bends has to be bent before it's fully cured, cured Bars cannot be bent.
> 
> I can see where it may be advantageous in some situations but it doesn't sound like it's something it will take over huge portions of the field until some big improvements are made to it.


Just like steel you can get bars that are coated.


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## Bryan Hale (Apr 30, 2019)

mark handler said:


> Just like steel you can get bars that are coated.



Frp or GFRP rebar are the best alternatives to traditional steel. These bars are when reinforced with corrode offer sustainability to the concrete structure and protect it from getting corroded. Another great feature is Glass fiber reinforced polymer is non-conductive to the electricity. You can see lots of major construction projects such as bridges, mines, highway infrastructure are built with GFRP material to get sustainability and long life span to the concrete structure. See here a great resource on how GFRP Rebar strengthens the concrete structures.


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## ADAguy (Apr 30, 2019)

Bet it won't work for a vault!


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## Bryan Hale (May 7, 2019)

ADAguy said:


> Bet it won't work for a vault!


Can you explain why it won't work for a vault?


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## Msradell (May 7, 2019)

Bryan Hale said:


> Can you explain why it won't work for a vault?


I'm not the OP that said it wouldn't work for a vault but I guess is because it's too easy to cut. It has a strength required but is much more fragile than steel would be.


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## ADAguy (May 8, 2019)

Diamond blade saw will cut right through them (smiling)


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## linnrg (May 8, 2019)

ADAguy said:


> Diamond blade saw will cut right through them (smiling)



Blades go thru steel rebar too


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## mark handler (May 8, 2019)

Bryan Hale said:


> Can you explain why it won't work for a vault?


they can it's just easier to cot through to get to the money.


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## mark handler (May 8, 2019)

No Steel?
The gang breached the vault by drilling a series of holes through 20 inches of concrete with a stolen Hilti DD 350 diamond coring rig (videos in link).

Police officials know that was the tool because the robbers left it and others behind. The DD 350 rig is the second largest coring tool sold by Hilti. It weighs 76 pounds and goes for about $8,700 (US). There are believed to be only a few thousand of this model in the U.K; the one used in the robbery appears to have been stolen from a London jobsite late last year.

https://www.toolsofthetrade.net/power-tools/corded-tools/tools-of-the-bank-robbing-trade_o


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## jar546 (May 8, 2019)

Francis Vineyard said:


> Now I recollect we have an engineer here that uses the fabric applied to basement foundation walls for repairs. Interesting concept.



I have seen that as well when I lived in the land of basements.


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## Bryan Hale (Jul 30, 2019)

GFRP rebar are the best solution as concrete reinforcement. This material increase the life of concrete structure and save it from harsh weather conditions, corrosion and rust. Mechanical and physical properties of glass fiber reinforced polymer are countless (see here How GFRP in concrete can strengthen the concrete infrastructure.


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## mark handler (Jul 30, 2019)

Bryan Hale said:


> GFRP rebar are the best solution as concrete reinforcement. This material increase the life of concrete structure and save it from harsh weather conditions, corrosion and rust. Mechanical and physical properties of glass fiber reinforced polymer are countless (see here How GFRP in concrete can strengthen the concrete infrastructure.


So, Bryan...Are we selling something?


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## ADAguy (Jul 30, 2019)

If not metal, it seems you might be able to burn through it. 
Does it have any Green benefits as in made of recycled material?


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## mtlogcabin (Jul 30, 2019)

Bottom line is the installation has to be engineered and it is not a size for size replacement  under the IRC tables for steel
https://www.icc-es.org/wp-content/uploads/report-directory/ESR-3403.pdf


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## mark handler (Jul 31, 2019)

ADAguy said:


> Does it have any Green benefits as in made of recycled material?


Might become cost effective when steel prices jump again. (Green as in money)


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## mark handler (Jul 31, 2019)

ADAguy said:


> If not metal, it seems you might be able to burn through it.
> Does it have any Green benefits as in made of recycled material?


https://www.allthingsfibers.com/2018/04/environmental-impact/
Comparing 4.5 lbs/yd3 of macro-synthetic fiber to be functionally equivalent in performance to #4 rebar @ 12” c.c., the carbon footprint of the required PFRC was 20,542 kg CO2eq while that of steel reinforced concrete floor was 46,931 kg CO2eq in this case study.  This translated to a CO2eq of 0.137 kg/ft2 (8 inch thick floor) with fiber while the corresponding value for steel was 0.312 kg CO2eq/ft2.
Thus, the carbon footprint of a 150,000 ft2 floor could be reduced by 56% relative to the carbon footprint of the corresponding steel reinforced floor.​


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## ADAguy (Jul 31, 2019)

Now that "could" make a difference. 

Is it also lighter and if so it would be faster to install, no?

Can it be cut with hand tools?


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## Msradell (Jul 31, 2019)

ADAguy said:


> Now that "could" make a difference.
> 
> Is it also lighter and if so it would be faster to install, no?
> 
> Can it be cut with hand tools?


Yes, it can be cut with hand tools. The bigger problem is bends. They can only be made before the resins harden.


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## Mark K (Aug 1, 2019)

There are two major problems with the use of GFRP rebar.  First it is not recognized in the building code and second its engineering properties make it unsuited for many uses.

The concrete code assumes that the rebar will not fail when the bar starts to yield.  This helps to assure that overloaded beams will exhibit significant deflection prior to failing.  This allows those using the building to realize that there is a problem and thus take steps to prevent a catastrophic failure.

This product should NOT be used when the member must resist seismic forces.

In the future the environmental impact of rebar will be reduced if not eliminated when renewable energy is used and when the mills for making steel use electricity to melt the steel.  I will also suggest that the environmental impact of concrete is probably much worse than that of the rebar.  I believe that the environmental impact of concrete will be mitigated by the use of other cementitious materials and by the use of carbon capture which can capture the carbon released during the manufacturing of cementitious materials.  This captured carbon will likely then be injected into the concrete improving the properties of the concrete..


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## mark handler (Nov 12, 2019)

What’s Up With Fiber-Reinforced Concrete?
November 11, 2019
https://www.protradecraft.com/video/whats-fiber-reinforced-concrete?eid=216320023&bid=2557139




Does adding fibers to concrete make it stronger or what?
Concrete reinforced with steel is the foundation of our modern society. Reinforcement within concrete creates a composite material, with the concrete providing strength against compressive stress while the reinforcement provides strength against tensile stress. But, while steel reinforcement solves one of concrete’s greatest limitations, it creates an entirely new problem: Corrosion of embedded steel rebar is the most common form of concrete deterioration. So what are we doing about it?
Hey, I’m Grady, and this is Practical Engineering. On today’s episode, we’re testing out some innovations in concrete reinforcement.
Although unprotected steel is naturally prone to corrosion, or rusting, when it gets embedded into concrete, certain factors usually work to protect it. First is the obvious protection of simply being shielded from the outside environment by a relatively impermeable and durable material. Water and contaminants usually can’t make their way through the concrete to the steel.
The second form of protection is the alkaline environment. The high pH of normal concrete creates a thin oxide layer on the steel that provides protection from corrosion.
But, in some cases, this protection isn’t enough. One of the main sources of corrosion to rebar is salt. Whether through exposure to saltwater near a marine environment or application of deicing salts to make roadways safer during the winter, these chloride ions can make their way through the concrete, corroding the steel reinforcement. And when steel corrodes, it creates iron oxide that expands inside the concrete. This expansion generates stress, sometimes called oxide jacking, and is the one of the primary causes of concrete deterioration.
Cracks in the Cover
So, how do we prevent these chloride ions and other contaminants from reaching the steel and causing corrosion? The first line of defense is cover.
Cover is the minimum distance between the outside surface of the concrete and the reinforcing steel.
And, depending on exposure and application, certain codes specify different amounts of concrete cover, generally between 25 and 75 millimeters or 1 to 3 inches. Cover is one of the reasons good concrete work takes so much effort before the concrete ever shows up on the job site. Installing strong formwork and lots and lots of wire tying all the reinforcement together help to make absolutely sure that, through all the jostling and walking over and general chaos that comes when it’s time to actually place concrete, the rebar stays where it was designed to be embedded within the final product. Neglecting these steps can cause rebar to sink to the bottom of a slab or come too close to an outside surface before the concrete cures, eventually leading to premature corrosion of the reinforcement due to lack of cover.
But, even with adequate cover, any crack in the concrete can allow contaminants and water into direct contact with the reinforcement. And it won’t surprise you to learn that cracks in concrete aren’t all that rare. Most concrete shrinks as it cures which can lead to cracks. Changes in temperature also cause expansion and contraction which can lead to cracking. Concrete can also crack under normal, expected loading conditions due to the way the steel takes up stresses within the material.
One way to solve this issue is by pre-stressing the rebar, a topic I discussed briefly in a previous video and something I’d like to dive deeper into in the future. But today I want to show another option for reducing these cracks.
Fiber-Reinforced Concrete
Fiber-reinforced concrete is pretty much exactly what you’d expect it be. It’s not a new idea by any means, but our understanding and use of different kinds of fibers within a concrete mix continues to grow. Adding glass, steel, or synthetic fibers to concrete can provide a lot of benefits, but one of the most important is crack control.
I constructed three nearly identical reinforced concrete beams to show how this works, and I let them cure for about a week. The first one only has steel rebar as reinforcement. I’m using my hydraulic press to test out the strength of each beam and see how it performs prior to failure. And I’m using tons as a measurement of force on these beams, just because that’s what the gauge says, but the units are completely arbitrary to the demo. (If you prefer SI [Système Internationale, or the metric system], just pretend these are metric tonnes.)
As I increase the load on the beam, you see cracks starting at only around 3 tons. These cracks form because steel stretches a little bit as it takes up the tensile stress in the concrete. The beam is holding the load just fine and isn’t even close to failure, but concrete can’t stretch along with the steel so it has to crack. You can imagine how these cracks could let water and air into contact with the reinforcement and eventually deteriorate the concrete.
(Those cracks are the important part of this demo, but I went ahead and increased the load until the beam failed because, hey, that’s what hydraulic presses are good for right?)
For these next two beams, I included fibers in the concrete mix: one beam has steel fibers and the other has glass fibers. The steel rebar and fibers team up to resist tensile stresses in the beams. The rebar provides large scale reinforcement to resist tension across the entire structural member, and the fibers provide small scale reinforcement to resist localize tension that causes cracking.
When I load these beams to 3 tons, you can’t see a single crack. In fact, for both of these beams, I didn’t see any cracks form until almost double that. and even then the cracks were much smaller. Both beams failed at about the same load as the first, one, which I expected. Like I said, the fibers don’t really add much overall strength to the beam, but you can easily see they could go a long way in preventing corrosion of steel rebar.
Alternatives to Steel Rebar
You may be wondering why are we even using steel for reinforcement at all? Steel is relatively inexpensive, well-tested, and strong, but there are lots of other materials that with excellent mechanical properties that don’t face this issue of corrosion. For very corrosive environments, we sometimes use epoxy-coated rebar or even stainless steel, but there are some emerging alternatives like Fiber Reinforced Polymers or FRP bars. This is reinforcement made of basalt, remelted volcanic rock forced through tiny nozzles to create fibers that are extremely strong.
Options like this often cost more than steel rebar, in some cases a lot more. But, the major impediment to the use of these newer, more innovative types of reinforcement isn’t just the cost. It’s easy to see that those additional costs may be offset by the increased lifespan of the concrete. Another inhibition comes simply from the lack of widespread use. Innovation happens slowly in civil engineering because the consequences of failure are so high. Gaining confidence in a design has as much to do with engineering theory as it does to simply seeing how well similar designs have performed in the past.
But many engineering disasters have come not at the expense of bad design, but actually bad maintenance, so long-term durability can be just as important to public safety as other design criteria. We’ll certainly be seeing more innovative ways to reinforce concrete in the future, including the options I mentioned in this video.
Thank you for watching, and let me know what you think!
—This video is from Practical Engineering's YouTube channel, which has a lot more engineering explainer videos.


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