Still fixing work involves following engineering drawings that detail the type of bar and the spacing used and setting out the work. The reinforcing bars are tied together with wire, which is cut using nips, or electric rebar tiers. Steel fixers are also responsible for attaching ‘spacers’ and ‘chairs’ that determine the amount of concrete cover.
Reinforced concrete (RC) is a composite material in which concrete’s relatively low tensile strength and ductility are counteracted by the inclusion of reinforcement having higher tensile strength or ductility. The reinforcement is usually, though not necessarily, steel reinforcing bars (rebar) and is usually embedded passively in the concrete before the concrete sets. Reinforcing schemes are generally designed to resist tensile stresses in particular regions of the concrete that might cause unacceptable cracking and/or structural failure. Modern reinforced concrete can contain varied reinforcing materials made of steel, polymers or alternate composite material in conjunction with rebar or not. Reinforced concrete may also be permanently stressed (in tension), so as to improve the behaviour of the final structure under working loads.