Recently, composite materials made from fibers embedded in a polymer resin, also known as fiber reinforced polymers are an alternative to steel reinforcement for concrete structures. Fiber reinforced polymer aramid (AFRP), carbon fiber reinforced polymer (CFRP) and glass fiber reinforced polymer (FRP) bars are the products commercially available for the construction industry. They have been proposed for use instead of steel or prestressed steel cables nonprestressed or prestressed concrete (ACI 440R 2006). The problems of steel corrosion is avoided with the use of FRP because fiber reinforced non-metallic materials are non-corrosive. Furthermore, FRP materials have several properties including high tensile strength which makes them suitable for use as structural reinforcement.
In addition, codes and design provisions have been
recently developed guidance for the use of FRP bars in concrete structures for
bridges and buildings (ACI 440H 2000, CSA 2000, ISIS-Canada, 2000).
The bond properties are responsible for transferring the
load of concrete to strengthen and develop the necessary restraint in
strengthening the balance, especially when the concrete is cracked. The service
limits in FRP reinforced concrete elements, such as deflection, crack width and
crack spacing is directly influenced by the properties of link reinforcement in
concrete. Fiber reinforced polymer bars are anisotropic materials. Factors such
as the type and amount of fiber and resin, fiber orientation and quality
control during the production process plays a major role in the mechanical
properties. If rebar carbon FRP (CFRP bar Isorod Pultrall, ADS Composites
Group), when comparing a steel rod of 11.3 mm reinforced carbon fiber with a
diameter similar about 9.5 mm, the results show that the tensile stress-strain
curves of the CFRP bar is linear up to fracture (All FRP bars is linear elastic
to failure).
The tensile strength of at least 1500 MPa, three times
with reinforcing steel. The elastic modulus of the CFRP bar is 128 GPa, about
65% that of steel. CFRP bar set close to the bond strength to concrete even as
a steel bar diameter 11.3 mm. (Benmokrane et al. 2001) As for glass FRP bars
(GFRP bar ASLAN 100 Hughes Brothers, Inc.), tensile strength of 9 mm GFRP bar
is 760 MPa and a modulus of elasticity is 40.8 GPa , much lower than for steel.
For more information : http://www.frpdistributors.com
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