Reinforced concrete

Reinforced concrete
A heavy, reinforced concrete column, seen before and after the concrete has been cast in place around its rebar frame
Material type	Composite material
Mechanical properties
Tensile strength (σt)	Stronger than concrete

Reinforced concrete, also called ferroconcrete, is a composite material in which concrete's relatively low tensile strength and ductility are compensated for by the inclusion of reinforcement having higher tensile strength or ductility. The reinforcement is usually, though not necessarily, steel reinforcing bars (known as rebar) and is usually embedded passively in the concrete before the concrete sets. However, post-tensioning is also employed as a technique to reinforce the concrete. In terms of volume used annually, it is one of the most common engineering materials.^[1][2] In corrosion engineering terms, when designed correctly, the alkalinity of the concrete protects the steel rebar from corrosion.^[3]