Which type of decks act integrally with the steel superstructure and become the top flange of the entire floor system?

Which type of decks act integrally with the steel superstructure and become the top flange of the entire floor system?

• A. Orthotropic decks
• B. Grid decks
• C. Steel decks
• D. Concrete decks

Answer: (A)

Orthotropic decks are designed to work as part of the steel frame, forming a continuous, efficient floor system. Their steel plate is reinforced with longitudinal ribs and stiffeners that connect directly to the main girders, and when tied into the structure with shear connections, the deck and girders act together as a single unit. In this arrangement the deck itself becomes the top flange of the entire floor system, providing the bending resistance and surface in one integrated action. Grid decks don’t create a continuous top flange; concrete decks rely on a concrete topping rather than the deck steel acting as the primary top flange, and steel decks in general do not automatically establish this integrated top-flange behavior unless it’s the orthotropic type.

Orthotropic decks are designed to work as part of the steel frame, forming a continuous, efficient floor system. Their steel plate is reinforced with longitudinal ribs and stiffeners that connect directly to the main girders, and when tied into the structure with shear connections, the deck and girders act together as a single unit. In this arrangement the deck itself becomes the top flange of the entire floor system, providing the bending resistance and surface in one integrated action. Grid decks don’t create a continuous top flange; concrete decks rely on a concrete topping rather than the deck steel acting as the primary top flange, and steel decks in general do not automatically establish this integrated top-flange behavior unless it’s the orthotropic type.