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Telescopic Beam-to-Beam Connection

BSF 450 kN, Bean-beam connection

USP

  • Corbel-free connection designed for beam-to-beam applications
  • Maximum vertical load capacity of 450 kN
  • Fast and safe installation with the steel knife retracted during erection
  • Clean architectural finish with no visible supporting corbels
  • Supports flexible beam layouts, including cantilevered and T-connections
  • Documented design guidance, reinforcement details and calculation tools

BSF 450 B-B is a telescopic steel connection developed for transferring heavy vertical loads between precast concrete beams. The system eliminates traditional concrete corbels and creates a clean, unobstructed beam-to-beam connection with a smooth soffit.

The connector is designed for beam-to-beam applications. It has a maximum vertical load capacity of 450 kN and a minimum beam dimension of 190 x 440 mm. The SF 450 B-B beam-to-beam receiving unit weighs 2.70 kg.

Function and Design

The BSF 450 B-B system consists of three main components: a B 450 beam unit cast into the supported beam, an SF 450 B-B receiving unit cast into the supporting beam, and an S 450 solid steel sliding knife that transfers the load between the two beams.

During erection, the knife is retracted and protected inside the B 450 beam unit. Once the supported beam is correctly positioned, the knife is extended into the SF 450 B-B receiving unit. The load is then transferred through the steel knife and into the specified anchoring reinforcement in both precast beams.

Materials and Finish

The three principal components of the BSF 450 B-B system are manufactured from S355 steel. The threaded rods are grade 8.8, and the stop washers are manufactured from S355 steel. The recess boxes are manufactured from thin sheet steel and supplied in standard finish.

Applications

BSF 450 B-B is designed for heavy-duty connections between two precast concrete beams. The corbel-free arrangement is particularly useful where architectural appearance, clear headroom, efficient formwork and flexible beam layouts are important. Dedicated design guidance is available for cantilevered beam-to-beam connections, T-connections and two-sided T-connections.

Installation and Fire Performance

The telescopic design supports fast and safe erection because the knife remains inside the beam unit until the beam is in position. After installation, the connection can be protected by the surrounding concrete and completed in accordance with the project-specific fire-protection design. The steel components have reaction to fire Class A1 according to EN 13501-1.

Documentation and Design

Technical memos cover capacities, main dimensions, reference levels, tolerances, torsion, expansion joints, seismic design proposals, reinforcement design and installation guidance. Dedicated reinforcement guidance is available for cantilevered beam-to-beam connections, T-connections and two-sided T-connections. A BSF calculation tool is also available for structural design.

BSF products are manufactured under CE-marked production in accordance with EN 1090. The declared BSF 450 B-B vertical load capacity is 450 kN, based on minimum concrete strength class C35/45 and project-specific reinforcement design.

Design and reinforcement must be verified for both beams, the actual loads, connection geometry, tolerances and project conditions using the current technical documentation

Maximum vertical ULS load
450 kN
Fire resistance with 25 mm concrete cover
R60
Minimum column width
330 mm
Minimum beam width
190 mm
Minimum beam height
440 mm
Steel knife material
S 355
Half-round steel and steel plate
S 355
S 450, kniv
35 kg
B 450, bjelkeenhet
10.6 kg
SF 450 B-B, bjelkeenhet
2.7 kg
Anchorage reinforcement. Steel grade 500C shall be used
Ø 12 and Ø 16 mm
Threaded bars to carry forces RHO and RHU. Bars are grade 8.8 steel
M12 and M16
Minimum concrete grade
C35/45

  • BSF 450 k N bjelke bjelke tegning
    BSF 450 k N bjelke bjelke tegning