Hidden Corbels are fastening components used to create hidden connections of precast beams to precast columns.

The corbels transfer forces from the beam to the column during both erection and service. In terms of bending moment, they act as pinned connections at the ends of the beams. They can also transfer torsion from the beam end to the column, enabling the installation of hollow core slabs on one side of the beam without additional temporary support. The corbels include built-in restraints against joint opening and are capable of transferring horizontal loads, which provides advantages in robust design.

Main features of Hidden Corbels:

• Connection Usage
  • Precast beam → Precast column connection
  • Steel box beam → Precast column connection (with compatible end detailing)

• Structural Features
  • Three-part design: column part, beam part, interconnecting tongue
  • Vertical adjustment with erection pack plate
  • Gap between column face and beam end remains ungrouted
  • Not suitable for transferring bending moments from the beam end

Approvals
Finland: 5B EC 2 178