Behavior of corroded bonded fully prestressed and conventional concrete beams

Abstract

Prestressed concrete is widely used in the construction buildings. And corrosion of steel is one of the most important and prevalent mechanisms of deterioration for concrete structures. Consequently the capacity of post-tension elements decreased after exposure to corrosion. This study presents results of the experimental investigation of the performance/behavior of bonded fully prestressed and conventional concrete beams, with 40MPa compressive strength exposed to corrosion. The experimental program of this study consisted of three fully prestressed and two conventional concrete beams with overall dimensions equal to 150×400×4500mm. The variables were considered in terms of corrosion exposure effect, prestressed level, and corrosion location effect for fully prestressed beams. Mode of failure, cracking width/distribution, ultimate load and the corresponding deflection of each beam were recorded. The results showed that the fully prestressed beam in comparison with conventional beam was considered to be even more resistance to corrosion because it was perceived to be crack-free as a result of prestressing. Also the mention deterioration incident in fully prestressed beams fully corrosion exposure level unnoticed that deterioration incident in partially corrosion exposure level. The most of deterioration incident in fully prestressed beam acts on compression of non-prestressed steel reinforcement. Because the bonded tendons are less likely to corrode. Cement grout/duct is a barrier to moisture and chloride penetration, especially plastic duct without splices. The theoretical analysis based on strain compatibility and force equilibrium gave a good prediction of the deformational behavior for fully prestressed beams.