Structural Performance of Deteriorated and Strengthened Precast Concrete Segmental Beams with Epoxy Joints under Concentric and Eccentric Loads

Deteriorated segmental beam failure in civil engineering constructions is caused by environmental conditions, material deterioration, and design errors. Effective maintenance and rehabilitation techniques require a thorough understanding of these reasons. Chloride-induced corrosion of reinforcing steel due to marine circumference cycles causes corrosion, bond losses, and reduced beam capacity. Structural distress can result from reduced steel cross-sectional area or loss of bond between concrete and reinforcing steel. The current research focuses on studying the effect of deterioration (accelerated corrosion process) on the structural performance of prestressed precast concrete segmental beams under concentric and eccentric loads. Six segmental beam specimens with 1800 mm length and hollow cross-section dimensions of 300×300 mm were tested. The adopted variables included the presence or absence of damage (corrode), load type (concentric or eccentric), and presence or absence of externally bonded carbon fiber reinforced polymer strips. All beam specimens were clamped at the ends, then the middle segments were loaded by applying a vertical load with eccentricities of 0, and 100 mm to achieve the required bending and torsion. It was concluded that a 15% corrosion of reinforcement causes a deterioration of concrete strength, which leads to a decrease in the ultimate load-carrying capacity by about 23% under concentric load and 19% under eccentric load. It found that as vertical deflection and twist angle increased, in accompanied with the vertical load, the deteriorated specimens experienced a gradual degradation in the stiffness. When compared to control specimens, repaired specimens demonstrated superior load-carrying and energy-absorbing capabilities.