Performance of Prestressed Concrete Bridge Girders Exposed to Fire

This paper presents an investigation into performance of prestressed concrete bridge girders exposed to fire. A numerical model, in the form of a computer program, for tracing the behavior of prestressed concrete (PC) bridges with T girders subjected to fire is presented. The three stages associated with the numerical procedure for evaluating fire resistance of PC bridge girders; namely, fire temperature calculation, cross sectional temperature evaluation and strength and deformation analysis in girders are explained. A simplified approach to account for deformations under fire conditions is incorporated into the model. The applicability of the computer program for tracing the response of PC bridges, due to combined effect of fire and structure loading, is demonstrated through a case study. Through the results of case study, it is shown that the type of limit state adopted in defining failure has significant influence on the fire resistance of PC bridge girders