Performance evaluation of CFRP-wrapped columns under eccentric loading

Reinforced concrete (RC) columns are essential structural elements that primarily resist axial loads along with bending moments caused by eccentric loading conditions. In many existing structures, columns may experience deterioration, increased service loads, or design deficiencies, which can reduce their structural capacity and performance. Strengthening and rehabilitation of such columns are therefore necessary to ensure safety and durability. Carbon Fiber Reinforced Polymer (CFRP) has emerged as an effective strengthening material due to its high strength-to-weight ratio, corrosion resistance, durability, and ease of application. The present study investigates the performance of CFRP-wrapped reinforced concrete columns subjected to eccentric loading. Reinforced concrete columns of size 150 mm × 150 mm × 1200 mm were cast using M25 grade concrete. Each column was reinforced with four 12 mm diameter longitudinal bars and 8 mm stirrups spaced at 100 mm center-to-center. Different CFRP wrapping configurations were used to evaluate their effectiveness in strengthening the columns. Two types of strengthening techniques were adopted, namely full wrapping and strip wrapping using CFRP sheets of 0.42 mm thickness. The wrapping configurations included only middle span wrapping, one end and middle span wrapping, middle span and second end wrapping, and wrapping at both ends of the column. All specimens were tested under eccentric loading, and parameters such as ultimate load, axial stress, axial deflection, and axial strain were recorded and analyzed.