1
Faculty of Engineering,Razi Metallurgical Research Center
2
Department of Civil Engineering,Razi Metallurgical Research Center
Abstract
Abstract. The repair and strengthening of RC structures has become a major problem for civil
engineers in the past few decades. To satisfy this problem, a previous method for the repair and
strengthening of RC beams included bonding steel plates to the inferior structure. However, bonding steel
plates to concrete presents disadvantages, including corrosion of the steel/adhesive joints and the heavy
weight of the material. These problems increase installation and maintenance costs. The bonding of Fiber
Reinforced Plastics (FRP) to structures provides an attractive alternative to steel plates. This material
is corrosion resistant and lightweight, has a high strength-to-weight ratio and possesses nonconductive
properties. The use of Fiber Reinforced Plastics (FRP) in repairing and strengthening RC beams has been
researched in recent years. In particular, attaching unidirectional FRP to the tension face of RC beams has
provided an increase in the sti ness and load capacity of the structure. However, due to the brittle nature
of unidirectional FRP, the ductility of the beam decreases. Consequently, the safety of the structure is
compromised, due to the reduction in ductility. The purpose of this research is to investigate the behavior
of high strength reinforced concrete beams strengthened with FRP sheets. The major test variables included
the di erent layouts of CFRP sheets and the tensile reinforcement ratio. More particularly, change in the
strength and ductility of the beams, as the number of FRP layers and tensile reinforcement bar ratios are
altered, is investigated. Eight under-reinforced concrete beams were fabricated and tested to failure. With
the exception of the control beam, one or four layers of CFRP were applied to the specimens.
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