29/08/2026
Structural steel connections are the joints that link steel members (beams, columns, girders, braces) so the structure can safely transfer loads (weight, wind, seismic forces, etc.).
In the reel you shared, the long steel girder is being connected under a concrete structure — typically through steel-to-steel connections (welded or bolted to plates, brackets, or other steel members that are already attached to or embedded in the concrete).
Main Types of Structural Steel Connections
Type How it works Common uses Pros Cons
Bolted High-strength bolts clamp plates Beam-to-column, beam-to-beam, bracing Fast, easy inspection, reversible Requires precise holes, more parts
Welded Metal is fused with heat (arc welding) Rigid joints, moment connections Strong, continuous, clean look Needs skilled welders, harder to inspect
Riveted Hot rivets (rarely used today) Historic buildings Very strong historically Labour-intensive, outdated
Combined Bolts + welds Many modern buildings Best of both More complex design
Common Connection Configurations
1. Simple (Shear) Connections�Transfer vertical loads only. Allow some rotation.�Examples: Beam seated on a seat angle, or web cleats.
2. Moment (Rigid) Connections�Transfer both shear and bending forces. Keep the angle between members fixed.�Often used in frames that resist wind or earthquakes.�Usually fully welded or use heavy end plates with bolts.
3. Beam-to-Column Connections
* Fin plate / web plate
* End plate
* Seated connections
* Fully welded moment connections
4. Beam-to-Beam (Girder) Connections�Common in the type of long steel frames shown in the reel.�Often use splice plates, bolted or welded.
5. Column Base Connections�Steel column fixed to a concrete foundation via base plate + anchor bolts (sometimes with welds to the base plate).
6. Embedded / Cast-in Connections�Steel plates or sections are cast into the concrete during pouring. Later, structural steel is welded or bolted to these embeds.�This is the usual way steel meets concrete — not by welding directly onto the concrete itself.
Bolted vs Welded – Quick Comparison
* Bolted → Faster on site, easier quality control, preferred in many modern projects.
* Welded → Creates continuous strength, good for rigid frames, common for the kind of work visible in your reel (on-site welding of girders).
In Kenya and most places, both methods follow design codes (often based on Eurocodes, AISC, or local adaptations) and require certified welders or qualified bolting procedures for structural work.
Relevance to the Reel
The video shows a long steel girder/frame being welded while positioned under a concrete elevated slab.�Typical connections involved would be:
* Welding the girder to steel connection plates or brackets
* Possible splices along the length of the girder
* Attachment points that ultimately transfer load into the concrete structure via embeds or anchors
Important Professional Notes
* Structural connections must be designed by a qualified engineer.
* Welding of structural steel requires certified welders and often non-destructive testing (NDT).
* Incorrect connections can lead to serious structural failure.
* This is not DIY-level work for large beams like those shown.
Materials Commonly Used
* Structural steel sections (I-beams, H-beams, hollow sections, angles, plates)
* High-strength bolts
* Welding electrodes / filler metals suitable for structural grades
* Connection plates and stiffeners
These materials (steel sections, plates, welding electrodes, etc.) are the kinds of products available through suppliers such as wajenzistores.com.
