Structural Reliability of Prestressed UHPC Flexure Models for Bridge Girders

Ultrahigh performance concrete (UHPC) has been used in several bridges and other structures throughout the world and is beginning to gain more exposure in the United States. For UHPC to continue to gain acceptance for bridge design in the United States, design specifications and procedures must be established for bridge engineers to utilize. The flexural behavior at the ultimate limit state for an UHPC girder is still a significant design concern. Therefore, this research examined three analytical approaches to evaluate the ultimate flexural strength of UHPC girders. In addition, Monte Carlo simulations were performed to account for the variability of several parameters and to determine reliability indices using the three analytical methods. The analysis results show that using typical AASHTO procedures, acceptable levels of reliability can be achieved while allowing the use of familiar and noncomplex equations.