Which deck type includes orthotropic and grid decks as subtypes?

Which deck type includes orthotropic and grid decks as subtypes?

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

Answer: (A)

The materials and structural approach define the deck type here. Orthotropic decks and grid decks are both steel-based deck systems used on bridges, so they fall under steel decks. An orthotropic deck uses a thin steel plate stiffened by a network of ribs and stringers oriented in different directions, which creates high stiffness with relatively low weight and lets it efficiently transfer loads to the supporting girders—ideal for long spans. A grid deck, on the other hand, is built from a lattice of steel members forming a grid, providing good stiffness with less material and often serving as a form for a concrete layer or as the load-distributing deck itself. Because both rely on steel construction rather than concrete, the correct overarching category is steel decks. Concrete decks are a separate category built primarily from concrete, not steel.

The materials and structural approach define the deck type here. Orthotropic decks and grid decks are both steel-based deck systems used on bridges, so they fall under steel decks. An orthotropic deck uses a thin steel plate stiffened by a network of ribs and stringers oriented in different directions, which creates high stiffness with relatively low weight and lets it efficiently transfer loads to the supporting girders—ideal for long spans. A grid deck, on the other hand, is built from a lattice of steel members forming a grid, providing good stiffness with less material and often serving as a form for a concrete layer or as the load-distributing deck itself. Because both rely on steel construction rather than concrete, the correct overarching category is steel decks. Concrete decks are a separate category built primarily from concrete, not steel.