BSI PD 7974-3:2011
$215.11
Application of fire safety engineering principles to the design of buildings – Structural response and fire spread beyond the enclosure of origin
| Published By | Publication Date | Number of Pages |
| BSI | 2011 | 270 |
This Published Document provides a framework for developing a rational methodology for design using a fire safety engineering approach through the application of scientific and engineering principles to the protection of people, property and the environment from fire. The Published Document considers the following issues:
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the conditions within a fire enclosure and their potential to cause fire spread;
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the thermal and mechanical response of the enclosure boundaries and its structure to the fire conditions;
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the impact of the anticipated thermal and mechanical responses on adjacent enclosures and spaces;
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the structural responses of loadbearing elements and their effect on structural stability, load transfer and acceptable damage according to the design and purpose of the building;
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fire following structural impact to the building.
PDF Catalog
| PDF Pages | PDF Title |
|---|---|
| 13 | Figure 1 Overview of the PD 7974 series of Published Documents |
| 22 | Figure 2 Inter-relationship between PD 7974-3 and the other sub-systems |
| 27 | Figure 3 Methodology for interaction of all sub-systems in the PD 7974 series |
| 29 | Figure 4 �Interaction between the various professionals as part of the process in delivering a successful fire strategy |
| 30 | Figure 5 Interaction between the various professions and the design team in addressing PD 7974-3 factors |
| 34 | Figure 6 Routes for fire transmission |
| 39 | Figure 7 Procedure for quantitative analysis within PD 7974-3 |
| 43 | Table 1 Overview of means of analysis for each fire spread mechanism |
| 44 | Figure 8 Potential outputs that can be obtained from various analysis methods |
| 51 | Table 2 Flash-ignition temperatures |
| 53 | Figure 9 Configuration factors for typical scenarios |
| 54 | Table 3 Maximum permitted radiation dose to building occupants |
| 61 | Figure 10 Nomogram for modification factor for ventilation |
| 66 | Figure 11 Nominal standard fire curves |
| 68 | Table 4 Values of kb |
| 73 | Table 5 Notional radiation levels from openings in enclosures |
| 74 | Table 6 Effect of automatic sprinklers on expected fire conditions |
| 77 | Table 7 Guidance on the material surface emissivity of construction materials |
| 79 | Figure 12a) Time-temperature curves, at depths shown from surface for 1:2:4 Portland cement concrete with ham river sand and gravel aggregate – heated 2 hours |
| 80 | Figure 12b) Time-isotherms and colour changes for 1:2:4 Portland cement concrete with ham river sand and gravel aggregate – heated 2 hours |
| 82 | Figure 13 Temperature distribution in slabs exposed to the standard fire on one side Figure 14 �Temperature profiles at distances from the surface (mm) for a 300 mm × 300 mm concrete column for various fire resistance periods |
| 85 | Figure 15 Calculation of section factors |
| 86 | Table 8 Calculation of element factors (EF ) |
| 87 | Figure 16 Calculation of element factors |
| 88 | Table 9 Typical set of coating thicknesses for a profile spray-applied protection system |
| 89 | Figure 17 Typical set of board thicknesses for a box encasement fire protection system |
| 92 | Figure 18 Compartment parameters Table 10 �Location of columns between windows to avoid direct flame impingement Dimensions in metres |
| 93 | Figure 19 Spandrel beam with shielded flanges Table 11 Spandrel beams Dimensions in metres |
| 97 | Figure 20 Calculation methods for determining the temperature profiles though masonry elements |
| 98 | Figure 21 �Temperature gradient through autoclaved concrete masonry with a density of 400 kg/m3 to 800 kg/m3 |
| 106 | Table 12 �Recommended fire protection thickness to compensate for deficiencies in concrete thickness/reinforcement cover |
| 139 | Figure 22 Typical detail showing protection to a floor beam with a service penetration |
| 145 | Table 13 �Notional period of fire endurance for which imperforate condition can be assumed for unproven elements subject to fire exposure |
| 147 | Table 14 Partial safety factors for loads (illustrative) |
| 151 | Figure 23 General approach to structural fire safety design |
| 156 | Figure 24 Design methods for fire limit state (FLS) design adopted in BS EN 1992-1-2 |
| 158 | Figure 25 Principle design methodologies adopted in BS EN 1993-1-2 |
| 163 | Table 15 �Notional char depths for various species after 30 min and 60 min in the standard furnace test (BS 476-20) |
| 164 | Table 16 Values of kfi for different components/elements |
| 165 | Figure 26A Definition of residual cross-section and effective cross-section |
| 166 | Figure 26B Relationship between k0 and time of fire exposure for unprotected surfaces, and for protected surfaces where tch ≤20 min Figure 26C Relationship between k0 and time of fire exposure for protected surfaces where tch >20 min Table 16A Determination of k0 |
| 167 | Figure 27 Equations 85 to 87 illustrated |
| 169 | Table 17 �Minimum thickness requirements for dense and lightweight aggregate masonry, single-leaf, loadbearing walls (extracted from NA to BS EN 1996-1-2:2005, Table NA.3.2) |
| 172 | Figure 28 Vertical section on masonry (adapted from BS EN 1996-1-2:2005, Figure C.2) Table 18 �Values of constant, c, and temperatures q1 and q2 by masonry material – (extracted from BS EN 1996-1-2:2005, Figure C.2) |
| 176 | Figure 29 �Typical examples of concrete floor slabs with profiled steel sheets with or without reinforcing bars (BS EN 1994-1-2) |
| 177 | Figure 30 Examples of composite floor beams (BS EN 1994-1-2) |
| 178 | Figure 31 Examples of composite columns (BS EN 1994-1-2) |
| 180 | Figure 32 Schematic representation of the compressive and tensile forces of a floor zone during fire |
| 181 | Figure 33 �Illustration of the defection of a multi-zone composite floor system with protected and unprotected members |
| 182 | Figure 34 Illustration of catenary action developed in a multi–zone composite floor system |
| 186 | Figure A.1 Variation in thermal strain with temperature for siliceous and calcareous concrete |
| 187 | Figure A.2 Variation of specific heat with temperature for normal weight concrete (NC) and lightweight concrete (LC) as a function of temperature |
| 188 | Figure A.3 Variation of thermal conductivity of concrete with temperature |
| 191 | Figure A.4 Mathematical model for stress-strain relationships under compression at elevated temperatures (see BS EN 1992-1-2:2004, Figure 3.1) |
| 192 | Figure A.5 Variation in coefficient kc(q) for describing the characteristic strength, fc,k, for siliceous and calcareous aggregates at elevated temperatures (see BS EN 1992-1-2:2004, Figure 4.1) Table A.1 �Values for the main parameters of the stress-strain relationships of normal weight concrete with siliceous or calcareous aggregates (see BS EN 1992-1-2:2004, Table 3.1) |
| 193 | Figure A.6 �Stress-strain relationships for normal weight siliceous concrete at elevated temperatures (see BS EN 1994-1-2:2005, Figure B.1) |
| 194 | Figure A.7 �Stress-strain curves allowing for cooling of a grade 40/50 concrete (see BS EN 1994-1-2:2005, Figure C.2) |
| 195 | Figure A.8 �Coefficient kc,t (q) allowing for decrease of tensile strength (fck,t) of concrete at elevated temperatures (see BS EN 1992-1-2:2004, Figure 3.2) Table A.2 Values for the two main parameters of the stress-strain relationship – lightweight concrete at elevated temperatures |
| 196 | Table A.3 Reduction of strength at elevated temperature |
| 197 | Figure A.9 Reduction of strength at elevated temperature |
| 199 | Figure A.10 Thermal elongation of carbon steel as a function of the temperature |
| 200 | Figure A.11 Thermal elongation of austenitic stainless steel as a function of temperature |
| 201 | Figure A.12 Specific heat of carbon steels as a function of temperature |
| 202 | Figure A.13 Specific heat of stainless steels as a function of temperature |
| 203 | Figure A.14 Thermal conductivity of carbon steel as a function of temperature Figure A.15 Thermal conductivity of stainless steel as a function of temperature |
| 204 | Table A.4 Density of stainless steel at elevated temperatures |
| 205 | Figure A.16 Determination of heated perimeter (Hp) for various configurations of unprotected steel |
| 206 | Figure A.17 Determination of Hp for various configurations of protected steel members |
| 207 | Figure A.18 �Stress-strain relationships for hot finished, structural steel at elevated temperatures (see BS EN 1993-1-2:2005, Figure 3.1) |
| 208 | Table A.5 �Mathematical formulations of stress-strain relationships for hot finished structural steel at elevated temperatures (see BS EN 1993-1-2:2005, Figure 3.1) |
| 209 | Figure A.19 �Graphical presentation of the stress-strain relationships of hot rolled structural steel at elevated temperatures, with strain-hardening included (see BS EN 1994-1-2:2005, Figure A.2) Table A.6 �Reduction factors kq for stress- strain relationships of structural steel at elevated temperatures (see BS EN 1994-1-2:2005, Table 3.2) |
| 210 | Figure A.20 �Alternative stress-strain relationship for steel allowing for strain-hardening (see BS EN 1993-1-2:2005, Figure A.1) |
| 211 | Table A.7 �Strength reduction factor for structural steel grades 275 and 355 to BS EN 10025-1 and BS EN 10025-2 |
| 212 | Table A.8 Elevated temperature stress-strain data for grade 275 structural steel |
| 213 | Table A.9 Elevated temperature stress-strain data for grade 355 structural steel |
| 214 | Table A.10 Values for the three main parameters  of the stress‑strain relationships for cold worked reinforcing steel |
| 215 | Table A.11 �Values for the parameters of the stress-strain relationship of cold worked (cw) (wires and strands) and quenched and tempered (q & t) (bars) pre-stressing steel at elevated temperatures (see BS EN 1992-1-2:2004, Table 3.3) |
| 216 | Figure A.21 Reference curves for critical temperature of reinforcing and pre‑stressing steels Table A.12 Strength reduction factor for cold formed galvanized steel to BS EN 10147 |
| 217 | Figure A.22 �Reduction factors for the stress-strain relationship of cold formed and hot rolled thin walled steel at elevated temperatures Table A.13 Reduction factors for carbon steel for the design of class 4 sections at elevated temperatures |
| 218 | Figure A.23 Strength reduction factors (SRF) for grade 8.8 bolts in shear and tension at elevated temperatures Table A.14 Strength reduction factors for grade 8.8 bolts in shear and tension |
| 219 | Table A.15 Strength reduction factors for butt welds |
| 220 | Figure A.24 Strength reduction factors for fillet welds at elevated temperatures Table A.16 Strength reduction factors for fillet welds at elevated temperatures (see BS EN 1993-1-2:2005, Table D.1) |
| 221 | Figure A.25 Stress-strain model for stainless steel at elevated temperatures Table A.17 Stress-strain parameters for stainless steel |
| 223 | Table A.18 Factors for determination of strain and stiffness of stainless steel at elevated temperatures |
| 225 | Table A.19 Reduction factor and ultimate strain for the use of advanced calculation methods |
| 228 | Table A.20 Elastic modulus of aluminium alloys at elevated temperatures |
| 229 | Table A.21 �0.2% proof stress ratios, k0.2,q for aluminium alloys at elevated temperatures for up to 2 hours thermal exposure period |
| 230 | Table A.22 Design charring rates for timber, LVL, wood based panels and panelling |
| 232 | Figure A.26 Relationship between charring rate and time |
| 233 | Table A.23 Variation of specific heat capacity and density ratio of softwood at elevated temperatures |
| 234 | Figure A.27 Variation in specific heat of softwood and charcoal Figure A.28 Temperature-density ratio relationship for softwood with an initial moisture content of 12% |
| 235 | Figure A.29 Variation in thermal conductivity with temperature for wood and charcoal Table A.24 Variation of thermal conductivity with temperature |
| 236 | Figure A.30 Reduction factor for strength parallel to the grain for softwood Figure A.31 Effect of temperature on the elastic modulus of softwood parallel to the grain |
| 237 | Figure A.32 �Calculation values of thermal strain eT of clay units with unit strength 12 N/mm2 to 20 N/mm2 and units with a density range of 900 kg/m3 to 1 200 kg/m3 |
| 238 | Figure A.33 �Calculation values of thermal strain eT of calcium silicate units with unit strength 12 N/mm2 to 20 N/mm2 and a density range of 1 600 kg/m3 to 2 000 kg/m3 Figure A.34 �Calculation values of thermal strain eT of lightweight aggregate concrete units (pumice) with unit strength 4 N/mm2 to 6 N/mm2 and a density range of 600 kg/m3 to 1 000 kg/m3 |
| 239 | Figure A.35 �Calculation values of temperature-dependant material properties of autoclaved aerated concrete units with a density range of 400 kg/m3 to 600 kg/m3 Figure A.36 �Calculation values of temperature-dependant material properties of clay units with a density range of 900 kg/m3 to 1 200 kg/m3 |
| 240 | Figure A.37 �Calculation values of temperature-dependant material properties of lightweight aggregate concrete units (pumice) with a density range of 600 kg/m3 to 1 000 kg/m3 Figure A.38 �Calculation values of temperature-dependant material properties of calcium silicate units with a density range of 1 600 kg/m3 to 2 000 kg/m3 |
| 241 | Figure A.39 �Calculation values of temperature-dependant stress-strain diagrams of clay units with unit strength of 12 N/mm2 to 20 N/mm2 and a density range of 900 kg/m3 to 1 200 kg/m3 |
| 242 | Figure A.40 �Calculation values of temperature dependent stress-strain curves of calcium silicate units with strength of 12 N/mm2 to 20 N/mm2 and a density range of 1 600 kg/m3 to 2 000 kg/m3 Figure A.41 �Calculation values of temperature-dependent stress-strain curves of lightweight aggregate concrete units (pumice) with strength of 4 N/mm2 to 6 N/mm2 and a density range of 600 kg/m3 to 1 000 kg/m3 |
| 243 | Table A.25 Thermal properties of common types of glass Table A.26 Mechanical properties of some common glasses |
| 245 | Table A.27 Thermal properties of some common plastics |
| 246 | Table A.28 Mechanical properties of some plastics |
| 247 | Figure A.42 Flexural strength of glass polyester at elevated temperatures Table A.29 Mechanical properties of some typical resins |
| 248 | Table A.30 Mechanical properties of several types of fibre reinforcement Table A.31 Strength properties of polyester laminates at elevated temperatures |
| 249 | Table B.1 Comparison of expansion of materials used in composite sandwich panels Table B.2 Comparison of specific heat capacity of materials used in composite sandwich panels |
| 250 | Figure B.1 Thermal conductivity for various densities of mineral (rock) wool at elevated temperatures Table B.3 Thermal conductivity for various densities of mineral (rock) wool at elevated temperatures |
| 251 | Table B.4 Constants for calculating the thermal conductivity of mineral wool at elevated temperatures Table B.5 Thermal conductivity of cellular glass Table B.6 Thermal conductivity of expanded polystyrene |
| 252 | Table B.7 Thermal conductivity of extruded polystyrene Table B.8 Thermal conductivity of phenolic foam Table B.9 Thermal conductivity of polyisocyanate foam Table B.10 Thermal conductivity of rigid polyurethane foam |
| 253 | Table B.11 Thermal conductivity through the cell gas for various blowing gases Table B.12 Typical densities of core materials used in sandwich panels |
