Lifetime Reliability Analysis of Flexural Cracking for Existing Prestressed Concrete Bridge under Corrosion Attack

This paper presents the lifetime performance reliability of existing prestressed concrete bridges under corrosion attacks. The authors focus on prestressed concrete bridges subject to continuous deterioration of structural performances and reduction of structural reliability during their service life due to aggressive environmentsThe time-dependent reliability of flexural cracking of prestressed concrete beams under service limit state are concerned, corrosion attacks such as: sulfate attack, alkali-silica reaction,freeze-thaw attack, and chloride-induced reinforcement corrosion are discussed. The three kinds of typical corrosion models for the reinforced concrete beams are established. The limit state equation is derived by strictly adhering to the effect of an action and resistance formulas and requirements set forth in Chinese highway bride design specification. Through integrating first order reliability methods and the time discretized approach, the time-variant reliability of existing prestressed concrete brides are calculated, for illustrative purpose, the reliability of a typical post-tensioned simply supported prestressed beam that are widely used in Chinese highways are investigated.