Rebar (Reinforcing Steel)
CSI Division 03, Concrete
Steel bars embedded within concrete before it's poured, giving the finished concrete the tensile strength (resistance to bending and pulling forces) that plain concrete lacks on its own, since concrete is strong in compression but weak in tension, and rebar fills exactly that gap.
Why it matters
Concrete without adequate reinforcement can crack and fail under loads it would easily handle if properly reinforced, so rebar placement, meaning size, spacing, and position within the concrete, is engineered specifically for each structural element and inspected before the pour, since it's completely hidden once the concrete goes in.
On a real project
A structural engineer's drawings specify the exact size, spacing, and placement of rebar within a foundation wall. An [[career-ironworker|Ironworker]] crew ties the rebar cage to those exact specifications, and it's inspected and approved before the concrete truck is allowed to pour.
Who this matters most to
An Ironworker cuts, bends, and ties rebar into place according to the structural drawings. A Quality Control Manager performs a rebar inspection, checking size, spacing, and concrete cover, that's often a required special inspection before the pour can proceed.
Where this goes wrong
A rebar cage is tied with less concrete cover (the distance between the steel and the outer surface) than the drawings specify, and the error isn't caught before the pour. Years later, moisture reaches the under-covered steel and causes it to corrode and expand, cracking and spalling the concrete around it from the inside out.