Nominal Strength of Composite Prestressed Concrete Bridge Deck Panels

Precast prestressed concrete panels have been used as subdecks in bridge construction. To experimentally investigate the nominal flexural and shear strengths of this composite slab system, five full-scale model composite slab specimens were constructed and tested. One specimen modeled bridge deck condition well within a girder span, and the other four specimens represented geometric conditions that occur with skewed concrete diaphragms at 0°, 15°, 30°, and 40°. The slabs were statically loaded through a wheel footprint at preselected locations until failure occurred. To analytically evaluate the nominal strength for these composite slab specimens, yield-line and punching-shear theories were applied to the crack patterns generated during the ultimate load tests. These computations and the observed mode of failure for the specimens indicated that punching shear governed the nominal strength of the slabs. The nominal strength of the slabs significantly exceeded the design load requirements.