Experimental investigation of External FRP strengthening column against secondary moment of slender effect

The essential design code guidelines for Fiber Reinforced Polymer (FRP) strengthened Reinforced concrete columns are limited to short columns strengthened with FRP wrapping. As a result, they are primarily non-applicable to slender RC columns where there is a significant second-order/slenderness impact. The purpose of the current study was to experimentally recognize how effectively longitudinal carbon panels (CFRP) and basalt fiber-reinforced polymer (BFRP) lateral wrapping can reduce lateral deflection and increase the strength of variable thin square reinforced concrete columns. A total of 8 square RC columns of 120 mm width were performed in three groups, according to the slenderness ratio 22, 29, and 35. The strengthened columns were developed using two distinct strengthening techniques. The first is a longitudinal CFRP laminate with lateral partial BFRP wrapping (EBWGL) plus grooved bonding, and the second is a lateral partial wrapping (EBW) of the BFRP film. The column was tested with 30 mm eccentric compression. In general, the EBWGL reinforcement technique significantly improves the flexural strength of columns. Moreover, it is noteworthy that the EBW method did not considerably reduce the secondary effect as the slenderness ratio increased. The EBGWL has a great reducing effect that gets better as the slenderness ratio gets higher.