Rebar Works
Fabrication, installation, and inspection of reinforcement steel. El-Eman Office executes rebar and concrete works with supervision.
Reading the Bar Schedule Correctly
A mistake in reading the drawings leads to errors that are hard to correct after the concrete is poured. The bar schedule for each element gives the number of bars, their diameters, lengths, shapes and mark numbers, and the steel fixer must link this data to the structural details of the section. Before starting, the engineer should go over complex locations, such as where beams meet columns, with the foreman.
- Confirm the mark number, diameter and length of every bar in the schedule.
- Check lap lengths, anchorage lengths and hooks.
- Understand the order of steel layers in slabs (bottom and top).
- Locate the openings and sleeves reserved for pipes and cables.
Storage and Protection Before Fixing
Reinforcing steel is affected by moisture and soil. Bars should be lifted off the ground on supports, covered and sorted by diameter, and kept free of oil and mud. Light surface rust is usually not a problem, but deep flaking rust reduces the bar section and weakens the bond with concrete. Visibly bent or damaged bars are rejected.
It is also important to check the mill certificates for steel delivered to site and to avoid mixing grades, because a different grade changes the load capacity assumed in the design.
Controlling Cover and Spacing During Fixing
Concrete cover protects steel from corrosion and affects fire resistance and the life of the structure. To keep it in place, spacers or chairs are used under and beside the steel in sufficient numbers; placing them only at the ends of a beam is not enough. Stirrups must be tied to the main bars in their correct positions at the spacing shown on the drawings, with closer spacing near the ends of beams and columns where shear forces are greater.
- Secure the steel so it does not move during pouring and vibration.
- Make sure no tie-wire offcuts or loose wire remain inside the formwork.
- Lift any bar that has sagged or bent during work.
- Review the final arrangement before giving permission to pour.
Laps, Splices and Welding
When two bars must be joined, a lap is used with a length set by the design according to the diameter and the type of element. Splices should be placed away from the zones of highest stress where possible, and should not all be concentrated in one section. In some cases mechanical couplers are used. Welding rebar is permitted only for suitable steel types, under supervision and approved procedures, since careless welding can weaken the bar. The contractor should always refer to the specifications and drawings on this point.
Frequently asked questions
Can rusty steel be used in structural work?
Light surface rust that comes off when rubbed generally does not prevent use. Deep, flaking rust, or rust that has reduced the bar diameter, means the affected steel should be rejected. The decision rests with the supervising engineer.
Why must stirrup hooks have a specific angle?
A hook bent at the proper angle anchors the stirrup in the concrete core and stops it opening under load, whereas a hook with little bend may open and lose its role in resisting shear.
Who approves the steel before pouring?
The supervising engineer or site engineer reviews the reinforcement and approves it in writing. No element is poured before this approval, in line with the quality procedures agreed for the project.
