High-strength concrete (HSC) is increasingly being used in highway bridges to enable prestressed concrete (PC) girders of a given size to support larger loads or longer span. Even if it is not specified, it is frequently provided by the contractor to speed concrete strength development. Both shear design provisions in the American Concrete Institute (ACI) Code and the AASHTO Specifications are derived empirically for normal strength concrete (up to 8,000 psi) only. Because of their empirical origins and complicated expressions, it is nearly impossible to extend the current design provisions for application to HSC. This research project is divided into two parts. Part one studies the ultimate shear strength of the new Tx-girders as a function of concrete strength. Part two studies the end zone behavior of different sizes of Tx-girders and effects of tendon slip on web shear capacity.