Abstract: The research investigated the behavior of reinforced concrete (RC) columns which have high slenderness ratios, and this strengthens with GFRP wrapping laminate. Twelve RC columns having a circular cross-section with various slenderness ratios (H/D) 16, 18, 20, and 22 were tested experimentally under concentric axial load. The first group of columns was non-strengthened as control. Secondly, the fully strengthened with GFRP wrapping laminates in the hoop direction and thirdly, the partially strengthened with GFRP wrapping laminates in the hoop direction were tested. Then the numerical models were developed and validated with the experimental results. The numerically developed model was implemented to demonstrate the effect of changing the orientation of the GFRP laminates, in addition, the effect of applied the eccentric axial load on the capacity of the strengthened slender columns were explored. Lastly, the experimental results for unconfined and FRP-confined columns are compared with ECP and ACI codes provisions. It can be concluded that increasing the slenderness ratio of columns causes a reduction in the ultimate axial load, axial deformation arising from decreasing the column stiffness but increasing the lateral deformation. Fully wrapped enhanced the lateral deformation of slender columns by reducing them by 0.8 to 0.55 when compared to partially wrapped as the slenderness ratio increased from 16 to 22. The column capacity predicted by ECP is more conservative than ACI for unconfined and confined slender columns. GFRP hoop strengthening barely increased the resistance for slender columns, while GFRP strengthening in the longitudinal direction contributes to their capacities.
Keywords: circular columns; GFRP; Slenderness ratio; ductility index; initial load eccentricity.
Title: Performance and strengthening of the circular R.C. Columns with high slenderness ratios using GFRP External Wrapping
Author: Nehal M. Ayash, Abeer Fathy, Ata El-kareim Shoeib
International Journal of Civil and Structural Engineering Research
ISSN 2348-7607 (Online)
Vol. 10, Issue 2, October 2022 - March 2023
Page No: 10-33
Research Publish Journals
Website: www.researchpublish.com
Published Date: 17-November-2022
