Assessment of shear capacity of prestressed concrete members with insufficient web reinforcement using AASHTO LRFD general shear design method

Abstract

The shear capacity assessment of in-service bridges has become a major challenge for practicing engineers due to the growing inventory of aging bridges. Specifically, a question arises for the applicability of the general shear design provisions in AASHTO LRFD as a tool for evaluating the shear capacity of prestressed concrete members with insufficient web reinforcement, due to the beneficial effect of prestressing. To investigate the influence of prestressing on the shear capacity of prestressed concrete members with noncompliant web reinforcement, the influence of the prestressing on shear behavior was investigated with the emphasis on the distinctive behaviors of such members. Then a rational assessment procedure for general prestressed concrete members is provided. A simple modification to current AASHTO LRFD shear design method was proposed to accurately calculate the shear capacities of such members. The accuracy of shear capacity estimation using the proposed method has improved and it was validated with nonlinear finite element analysis and statistical analysis using the University of Texas Prestressed Concrete Shear Database.