AASHTO-LRFD Interface Shear Strength for superstructure tutorial is about interface shear force, nominal interface shear resistance and cohesion and friction factors. A horizontal shear force called interface shear develops at the interface between of the girder and the deck under gravity type of loadings. Interface shear force is resisted by cohesion, aggregate interlock and shear friction developed by the force in the reinforcement crossing plane of interface. All reinforcements resisting interface shear force shall be fully developed on both sides of the interface. First nominal shear resistance limit (K1f’cAcv ) is set to prevent crushing or shearing of aggregate along the shear plane. Cohesion and friction factor’s table is given.

Reference;
AASHTO LRFD Bridge Construction Specifications, 4th Edition