Steel Buildings in Europe

Part 2: Concept Design 2 - 58 5.7.3 Services integration The flat floor soffit allo ws unrestricted access for services below the floor, as shown in Figure 5.18. 1 3 2 60 200 5 4 1 NWC topping 2 A142 mesh 3 T12  1200 long tie bars @ 600 ctrs through holes in web 4 HEB 260 5 460  15 plate Figure 5.18 Slim floor construction – typical cross-section using precast units 5.7.4 Fire protection The concrete encasement around the beam is normally sufficient to provide up to 60 minutes fire resistance without additional protection. For 90 minutes fire res istance, an in tumescent coating or board protection to the flange plate is required. Correct deta iling o f transverse reinforcement is required, particularly for hollow core un its, where filling of the co res adjacent to the beam is necessary. Table 5.6 Span of slim floor beams comprising HE sections and welded bottom plate Typical beam size for slim floor beam span Span of slab (m) 5 m 6 m 7 m 8 m 5 HE 200A HE 240A HE 280A HE 300A 6 HE 240A HE 280A HE 300A HE 280A 7 HE 280A HE 300A HE 280B HE 300B 8 HE 280A HE 280B HE 300B HE 320B Slab depth equal to the beam depth, plus 50 mm The welded plate should be 150 mm wider than the HE section Table 5.7 Span of integrated beams cut from IPE sections with a welded bottom flange plate Typical beam size for integrated beam span Span of slab (m) 5 m 6 m 7 m 8 m 5 IPE 400 IPE 500 IPE 550 IPE 600 6 IPE 500 IPE 550 IPE 600 HE 500A 7 IPE 550 IPE 600 HE 500A HE 600A 8 IPE 600 HE 500A HE 600A HE 600B All section sizes are cut to be half the IPE section sizes given A 20 mm thick welded bottom flange plate is used in all cases