reinforced concrete
A staircase supported by steel-reinforced concrete, usually poured in place and often integrated with the building frame.
A reinforced concrete staircase is a set of steps in a built object whose supporting framework is built of concrete reinforced with steel bars (rebars) and usually poured in place. Staircases of this material are commonly integrated with the overall framework of a concrete structure or the concrete core of a composite-frame building.
Concrete and embedded steel reinforcement form the supporting framework. A finish covering the steps does not determine this structural material.
Casting in place is usual without being an absolute requirement. The reinforcement condition is separate from whether stair components were prefabricated.
