Numerical Study of the Effect of Adding a Posttensioned Stiffener Layer on the Flexural Strength of Reinforced Concrete Beams

Retrofitting of buildings and improving their performance has received a lot of attention from researchers and engineers in recent years. With the advancement of technology and the presentation of new materials in the field of construction, the quality of retrofitting and improving of structures has also enhanced. Many structures in the world have been built using reinforced concrete materials, which have exhibited a good performance during previous earthquakes, too. The reinforcement of these structures and the presentation of new solutions to improve their performance have also been studied by many researchers and various solutions such as the use of concrete jackets have been proposed and applied. In the present study, using the posttensioned concrete, a new approach is presented to strengthen the flexural strength of reinforced concrete beams using ABAQUS software. In this method, by adding a posttensioned concrete layer to the reinforced concrete beam (base sample) from both sides, its flexural performance has been investigated. The results of the analyses indicate the appropriate behavioural compatibility of this method due to the high tensile capacity of steel cable, which can have a significant effect on ductility, improving  performance, increasing the capacity of reinforced concrete beams and transferring of the plastic joint from the middle span to  of the end of the beam.