Köco KSM Holland

Means of connection

In composite structures, the connection between steel and concrete must be resistant to shearing stress, so that a composite effect is achieved, resulting in composite action. At the beginning of composite construction, block dowels and loop anchors were used. Additional ancorage was always required to absorb the lifting-off forces.

The main drawback of these means of connection is the insufficient ductility, which can lead to a brittle failure in the composite joint. The production and welding-on of these parts is also very costly. The use of cold-forged shear connectors in the sixties led to the introduction composite construction on a large scale.

Figure 2: Obsolete means of connection (Block of anchor and loop anchors)

	Some important advantages of shear connectors in construction:
·	cost-effective production in large quantities and many different sizes
·	reliable and safe under static and dynamic stress
·	Mechanical interlock of steel and concrete, lifting-off of concrete slabs is prevented
·	high ductility, considerable increase in bearing capacity through plastic design
·	anchorage of steel parts in concrete for various load directions, no cracking forces because of mechanical interlock
·	individual design of reinforcement by pre-planned positioning of steel members in concrete
·	firm weids produced by stud welding, with negligible steel deformation
·	processing by trained operators, no highly qualified weiders required
·	electronically controlled and monitored stud welding equipment ensures repeatability and verifiable quality of the weld
·	internationally recognized regulations create a high degree of safety