Evaluation of revised details of end zone of the prestressed concrete I-girders using finite element method

Abstract

Prestressed concrete I-girders are becoming more widely used in bridges. However, the high prestressing force applied to these girders can lead to cracks in the end zone upon stress transfer. Recently, the standard drawing details for prestressed concrete I-girders were modified by the Ohio Department of Transportation (ODOT). The primary difference in the new drawings is the reinforcement details and usage of welded wire reinforcement at the end of the girders. In order to evaluate end cracking performance resulting from changes to the ODOT standard drawings, girders with various end reinforcement configurations were analysed using linear and non-linear finite element models. The strains and stresses at the end zone in the concrete and rebar were then evaluated. The non-linear finite element models were verified using available experimental data. After verification, the non-linear models were used to identify the location of the end zone cracks observed in the girders. The verified model was used to evaluate the revised details of end zone region. The results show that the modified details in the standard drawings meet the requirements of the AASHTO LRFD design specification. In addition, the end zone strains in the concrete and stresses in the reinforcement were reduced.