What is the primary role of reinforcement steel in a concrete slab?

• A. Tensile
• B. Compression
• C. Bending
• D. Shear

Answer: (A)

Reinforcement steel in a concrete slab serves to carry tensile forces. Concrete handles compression well but is weak in tension, so when a slab bends, tension develops on the bottom. The steel has high tensile strength and binds with the concrete, resisting that tension and preventing cracks from widening, which gives the slab ductility and the ability to carry bending moments. In this composite, the concrete mainly takes compression while the steel handles the tensile side, with shear typically addressed by other design features if needed. So the primary role is to resist tension.