The Right Concrete Reinforcement Longer-lasting structures

Introduction

Sustainability is a necessary consideration when it comes to designing and building structures. To be sustainable, a structure must be environmentally responsible and resource-efficient throughout the structure’s life-cycle. With consideration on sustainability, it is no longer just about building structures, but about building structures with the future in mind.

Background/Statement of Problem

Concrete is a building block for much of the world’s infrastructure. With

such grand scale use, it is crucial for concrete to be sustainable. In order to accomplish this, concrete must have a long lifespan. It may come as a surprise that the leading cause of concrete failure has nothing to do with the actual concrete itself, but rather due to the nature of the design. Concrete alone has a very long lifespan. It is when concrete is paired with steel rebar that problems can arise.

A well-known fact is that concrete performs well under compression, but lacks tensile strength. Reinforced concrete is a great way to counter this weakness. Concrete provides the performance in compression and the

reinforcement provides the tensile strength desired. Steel rebar is a leading reinforcement for concrete despite its inherent nature. Steel is not a naturally occurring substance and wants to return to its original state through a process known as oxidation, more commonly known as corrosion. Corrosion produces rust on steel rebar, a

byproduct of the oxidation process. Rust on steel rebar occupies a greater volume and creates tension in the concrete that can lead to cracks and failure of concrete structures. The corrosion of steel is delayed by a passive film that forms

“the leading cause of concrete failure has nothing to do with the actual concrete itself”

Sustainable (adj.) - Able to be maintained at a certain rate or level

The process of steel oxidation (corrosion) Image reproduced with permission of the American

Concrete Institute

What to look for: a view of corroded infrastructure

between the concrete and the steel. This layer breaks down in harsh environments or where concrete is exposed to intense chemicals such as deicing agents, corrosive agents, seawaters and other such chemicals and environments. This makes relying on the passive film an ineffective form of long term steel corrosion protection. Steel rebar may be widely used, but it is not the most sustainable option.

Environments where steel rebar corrosion is a concern: - Concrete exposed to deicing Salts (Parking structures, bridge decks, jersey barriers, parapets, curbs, retaining walls, slabs on grade and more) - Structures built close to or in water (Quays, retaining wall, piers, jetties, decks, bulkheads, floating structures, roads, buildings, swimming pools, aquariums and more) - Any structure subjected to corrosive agents (Wastewater treatment plants, petrochemical plants, liquid gas plants, pipelines/tanks for fossil fuel, cooling towers, nuclear power/dump plants and more) - Structures requiring low conductivity or electromagnetic neutrality (Hospitals, air control towers, toll road sensing arrays, specialized military structures and more) - Thermosensitive applications (Thermally insulated concrete housing, heated floors, apartment patio decks and more) Before

corrosion Corrosion

begins Further

corrosion, surface starts

to crack

Eventual spalling,

corroded rebar exposed

Steel

Gatorbar

Lifespan

“…a sustainable solution to concrete reinforcement.” GatorBar is a new product that provides a sustainable solution to concrete

reinforcement. Its Basalt Fiber Reinforced Polymer technology (or BFRP for short) allows for more resilient concrete that is both long-lasting and environmentally friendly. BFRP is part of a larger family of concrete

reinforcement known as fiber reinforced polymer reinforcement that has been used before, but at a higher cost than steel rebar. This higher cost is heavily dependent on the rate that FRP Rebar can be manufactured. Typical rates of production for FRP are 5 to 10 ft/min. GatorBar is a drastic change from that. Thanks to a proprietary manufacturing process, GatorBar is able to be produced at a steady rate of 75 ft/min

with capabilities of even 120 ft/min. Even at these increased speeds GatorBar maintains its quality. Made with only the highest quality basalt fiber and epoxy resin, GatorBar is a high-strength product at a lower, more affordable price than competitors, making it an economical concrete FRP reinforcement.

Price parity is not its only benefit. BFRP reinforcement has many material

properties superior to steel. When compared to steel rebar, GatorBar sports higher tensile strength, a 7x weight advantage and a 2x longer product life, while being manufactured from sustainable materials. Higher tensile strength of #3 GatorBar allows it to compete with #4 Steel rebar as a viable replacement. GatorBar’s 7x weight advantage over steel makes it easily handled and transported, greatly reducing labor and transportation costs. GatorBar’s 2x longer life span and composition of sustainable raw materials means that corrosion isn’t a concern, reducing costs to repair or renew materials down the road. Basalt fiber

also takes less energy to produce than steel, glass fiber or carbon fiber making GatorBar an efficient as well as effective product.

020406080

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Old Method Neuvokas'Process

Avg rate

Max rate

Steel rebar weighs 7x more than GatorBar. These two quantities above would be equal on a scale

GB has a 2x longer lifespan than steel

Rate of production comparison

In conclusion…

GatorBar’s BFRP design is the perfect concrete reinforcement for any

environment where steel corrosion is a concern. With a higher strength than steel rebar, a lower price than FRP competitors and a composition of raw natural materials, GatorBar is a strong and cost-effective reinforcement that is also efficient. All these features help to make GatorBar a sustainable choice in concrete reinforcement.

GatorBar is lightweight, allowing it to be easily handled

(Above) GatorBar can be tied up with any standard method whether by hand or with Kodi Klip. (Right) Chair it up and pour just like any other rebar.

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References "Corrosion of Embedded Metals." Corrosion of Embedded Materials. Portland Cement Association, n.d. Web. 08 June 2016. "Corrosion of Steel in Concrete." Www.nrmca.org. National Ready Mixed Concrete Association, 1995. Web. 8 June 2016. <http://www.nrmca.org/aboutconcrete/cips/25p.pdf>.