- Table 2 4 Fire Resistance Of Columns Fire Resistance Min R 60 R90 R 120 R 180 R 240 Fire Resistance Min R 60 R 90 Ta 1 (52.19 KiB) Viewed 29 times
Table 2.4 Fire resistance of columns Fire resistance (min) R 60 R90 R 120 R 180 R 240 Fire resistance (min) R 60 R 90 Table 2.5 Fire resistance of columns R 120 R 180 Source: Adapted from BS EN 1992-1-2. Eurocode 2: Design of concrete structures, Part 1-2: General rules-Structural fire design, BSI, London, UK, 2004, Table 5.2a for es 0.15h R 240 0.5 1.0 Reinforcement ratio 0.5 1.0 0.5 1.0 0.5 9 Minimum column width b Jaxis distance a (mm) H4, = 0.2 H₂ = 0.5 H, = 0.7 200/25 1.0 200/31 300/25 250/40 0.5 350/35 350/45 350/61 1.0 n₂ = 0.3 200/25 200/25 Minimum column width blaxis distance a (mm) n₁=0.5 250/35 350/25 200/40 400/25 200/45 300/25 200/40 300/25 300/45 550/25 250/50 400/25 450/50 200/36 300/31 300/45 400/38 350/45 450/40 350/63 450/75 600/25 450/50 550/25 550/55 600/25 500/40 250/46 350/40 350/53 450/40 350/57 300/45 550/25 250/40 550/25 450/50 600/25 450/45 600/30 500/60 600/50 500/60 600/45 600/70 450/51 450/70 600/60 4 = 0.7 350/40 550/25 300/50 600/30 500/50 600/40 500/50 600/45 500/60 600/50 600/60 600/75 Note I Note I Note I 600/30 Source: Adapted from BS EN 1992-1-2, Eurocode 2: Design of concrete structures, Part 1-2 General rules-Structural fire design, BSI, London, UK, 2004. Table 5.2b for e≤ 0.25h Note I: > 600 mm. Particular assessment for buckling is required. Exampic 4.4 Determine the fire resistance for a 300 x 300 mm column reinforced using 4 no. H25 bars which is carrying an axial load G₁ = 900 kN and Q₁ = 600 kN and bending moment G₁ = 40 kN and Q, = 27 kNm at room temperature. The column is in a braced frame with 1,= 3.0 m. Use fa = 40 N/mm² and f = 500 N/mm². PSF YG = 1.25 (dead load) and YG = 1.5 (live load). ₂ = 0.3. Cover to 8 mm dia. links = 30 mm.