Reinforced concrete

Reinforced concrete (Ferro concrete) is plain concrete in which reinforcement in the form of rods, bars ("rebars") or fibers have been incorporated to strengthen the naturally brittle concrete. The use of reinforced concrete is a relatively recent invention, usually being considered as covering the last 150 years, and its accidental discovery is commonly ascribed to a Parisian gardener named Monier in about the year 1860. The vast majority of reinforcement is made of steel, but fiber-reinforced plastic materials are available.

Non steel Reinforcement

Some construction cannot tolerate the use of steel. For example, MRI machines have huge magnets, and require nonmetallic buildings. Another example are toll-booths that read radio tags, and need reinforced concrete that is transparent to radio.

Related Topics:
MRI - Radio

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In some instances, the lifetime of the concrete structure is more important than its strength. Since corrosion is the main cause of failure of reinforced concrete, a corrosion proof reinforcement can extend the life substantially.

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For these purposes some structures have been constructed using fiber-reinforced plastic rebar, grids or fibers. The "plastic" reinforcement can be as strong as steel. Because it resists corrosion, it does not need a concete cover of 30 to 50 mm or more to protect the steel reinforcement. This means that FRP-reinforced structures can be lighter, have longer lifetime and for some applications be price-competative to steel reinforced concrete.

Related Topics:
Fiber-reinforced plastic

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Because FRP materials are linearly-elastic to failure, FRP-reinforced concrete elements will typically exhibit more brittle structural behaviour than those elements reinforced with traditional steel rebars. FRP-reinforced elements also exhibit vastly reduced fire-resistance. These two considerable weaknesses have limited its use to only extremely specialized applications.

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