Repair of corroded self-compacted reinforced concrete columns loaded eccentrically using carbon fiber reinforced polymer

Abstract

There is no research reported in the literature on the optimum repair scheme of corroded self-compacted Reinforced Concrete (RC) columns subjected to eccentric loading using carbon fiber reinforced polymer (CFRP). Therefore, this study presents a novel investigation on the above subject. Twenty-two RC columns (250 × 250 × 1000 mm) were casted using two steel ratios of 0.012 and 0.016. After 28 days of wet curing, 20 columns were immersed in 3 % saline solution and exposed to accelerated corrosion process using direct current supply for 21 days. The corroded columns were repaired using different schemes including near surface mounted (NSM) strips in the tension and compression zones, externally bonded CFRP sheet wrapped around the columns, and hybrid technique using NSM strips and CFRP sheet. All columns were tested eccentrically (e/h of 0.38) using universal testing machine. The test results showed that the hybrid repair technique contributes significantly to restore the original load capacity with average load increment of 16 %. The hybrid technique improved the deformability, toughness, and axial stiffness in the range of uncorroded columns. The failure mode of the columns was mainly delamination and crushing of the concrete cover in the compression zone accompanied by local buckling of the reinforcing steel.

Keywords

• Concrete
• Columns
• Corrosion
• Eccentricity