Steel Buildings in Europe

Part 2: Concept Design 2 - 50 5.4.3 Services integration Regular openings in the web allow ducts to pass through the beams as shown in Figure 5.10. Larger services equipment is located between the beams. Opening sizes should allow for any insulation around the services. Fabrication should be arranged to ensure web openings align through the beams along the building. The overall floor zone can be as low as 1000 mm for 15 m span beam s with regular 400 mm openings, which is much sh allower than the case where ducts pass below the beams. 150 140 600 100 50 ≈ 1050 1 2 3 1 Raised floor 2 Ducting and insulation 400 diameter 3 Lighting and Ceiling Figure 5.10 Cellular beam – Typical cross-section showing services integration 5.4.4 Fire protection Intumescent coatings are the p referred fi re prot ection syst em for ce llular beams, and are often applied off-site. Reference 7 gives advice on fire protection of beams with web openings. 5.5 Composite beams with precast concrete units 5.5.1 Description This system consists of steel beams with shear connecto rs that are often pre-welded to the top flange as part of the fa brication process. The beam s support precast concrete units with a stru ctural concre te inf ill ov er th e beam between the ends of the units, and often with an additional topping covering the units. The p recast concrete (P.C.) u nits are eith er hollow core, norm ally 150 - 260 mm deep, or solid planks of 75 mm to 100 mm depth. At the supp orts, deeper P.C. units are either chamfered on their upp er face or notched so that the in situ concrete fully encases the shear connectors. Narrow openings a re cre ated within the ho llow core units during the m anufacturing process to allow transverse reinforcem ent to be placed acro ss the beams and embedded in the precast units for a pproximately 600 mm on either side, as shown in Figure 5.11.