Abstract
The present study is an experimental comparison between the effect of increasing the compressive strength of the section and increasing the reinforcement ratio on the results of strengthening reinforced concrete beams with external steel plates of constant dimensions.
The experimental program consists of testing ten reinforced concrete beams. Five of them are without external steel plates to be the original specimens while the other five ones are provided with steel plates of same dimensions glued at the bottom face of the beams.
Three values of compressive strength (f'c) were used in this study which were (22, 45 and 71MPa) and also three ratios of internal reinforcement (ρ) which were (0.01411, 0.02116 and 0.03445) to investigate their effects on the strengthened beams behavior.
The results showed that the cracking load and the ultimate load can be increased up to (150% and 137%) respectively. Also, by increasing the section compressive strength all the properties of the strengthened beam can be improved while by increasing the reinforcement ratio the deflection and cracking can be reduced to improve the elastic behavior of the beam.
