New Strengthening Technique Using FRP to Improve the Confinement Effectiveness of the Rectangular Columns

Ahmed Mahmoud Khalifa(1*)

(1) Structural Engineering Department, Faculty of Engineering, Alexandria University, Egypt., Egypt
(*) Corresponding author

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In this study, new technique is proposed to improve the confinement effect of the rectangular columns confined with carbon fiber reinforced polymers (CFRP) wraps. In this technique, rectangular column cross-section is divided into nearly square parts at places of CFRP wrapping by drilling slots throughout the long side of the column. The slots allow the CFRP strips to wrap around and confined nearly square parts and then filled with epoxy paste and so increasing the effective confined area of the column cross-section. An experimental program was performed to examine the proposed wrapping technique. The research examines the effect of dividing the rectangular column cross section to two squares, the effect of number of CFRP wrapping layers (i.e., CFRP thickness), and the width of each layer. The experimental results indicate that dividing the rectangular cross section to squares increase the axial column capacity. Also, using the same amount of CFRP, increasing the CFRP strips width has greater effect on increasing the ultimate load capacity rather than decreasing the width with increasing the thickness.
An analytical model, conducted on rectangular columns confined by CFRP and verified using the test results, gave good agreement with the experimental results

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Rectangular Column; Confined Concrete; CFRP; Confinement

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