Rebar
Steel bar (short for steel bar), when aggregated into bars or bars, is a steel bar used as a tension device in reinforced concrete and reinforced masonry structures to strengthen and assist concrete in tension. Concrete has great strength under compression, but low tensile strength. Steel reinforcement significantly increases the tensile strength of the structure. The surface of the rebar has a continuous series of ribs, lugs or indentations to promote better bonding to the concrete and reduce the risk of slippage.