Large Shear Studs for Composite Action in Steel Bridge Girders

Shear studs used in composite steel bridge construction are typically 19.1 mm $(\frac{3}{4}$ in.) or 22.2 mm $(\frac{7}{8}$ in.) in diameter. This paper presents the development and implementation of the 31.8 mm $\left(1\frac{1}{4}\mathrm{in}\text{.}\right)$ stud diameter. Because the 31.8 mm $\left(1\frac{1}{4}\mathrm{in}\text{.}\right)$ stud has about twice the strength and a higher fatigue capacity than the 22.2 mm $(\frac{7}{8}$ in.) stud, fewer studs are required along the length of the steel girder. This would increase bridge construction speed and future deck replacement, and reduce the possibility of damage to the studs and girder top flange during deck removal. Studs also can be placed in one row only, over the web centerline, freeing up most of the top flange width and improving safety conditions for field workers. This paper provides information on the development, welding, quality control, and testing of the 31.8 mm $\left(1\frac{1}{4}\mathrm{in}\text{.}\right)$ stud. Information on the first bridge built in the state of Nebraska with the 31.8 mm $\left(1\frac{1}{4}\mathrm{in}\text{.}\right)$ studs is provided.