防火测试与美国建筑规范(外墙与屋顶系统)课件.ppt

Fire Testing and U.S.Building CodesExterior walls and roofs,Kurt Reimann,Ph.D.Shanghai April 2011,April 2011,Introduction to codes and standards,April 2011,General,U.S.fire safety requirements are not uniform across the country,but building and fire codes require minimum standards be met There is no federal building codeIndividual states can issue their own regulations,as long as they are not contradictory to federal regulationsSome states and local jurisdictions can have requirements that exceed IBC requirements,April 2011,Who issues codes?,International Code Council(ICC)almost all important building codes in U.S.National Fire Protection Association(NFPA)International Association of Plumbing and Mechanical Officials(IAPMO),April 2011,Who issues fire test standards:,ASTM vast majority of fire and performance standardsNFPA many are duplicates of ASTM standardsUL usually for listing(certifying)productsFM Global(Factory Mutual)usually for insurance purposesTrade associations for their own products,April 2011,International Building Code(IBC),Chapter 26,Plastic,April 2011,Requirements for foamed plasticsin building construction,general,There are exceptions but a minimum material requirement for foamed plastics is to pass the ASTM E 84 test with a flame spread index of not more than 75 and a smoke developed index of not more than 450(Class B).Again,there are exceptions but generally foamed plastic must be protected from living spaces by a thermal barrier of”gypsum wallboard or a barrier that will limit the average temperature rise of the unexposed surface to not more than 250oF(120oC)after 15 min.of fire exposure using the E 119 fire test.Note that fire tests listed here are almost always for assemblies of walls or roofs.Polyurethane foam is tested as a material in only the ASTM E 84 surface burning test or the potential heat test in NFPA 259.The following requirements are for flammability characteristics.Other requirements or specifications may also be required,e.g.,labeling.,April 2011,Important fire tests for plastics,ASTM E84 Surface burning rateASTM E119 Fire resistanceASTM E108 RoofsNFPA 259 Potential heatNFPA 268 Ignitability for wallsNFPA 275 Thermal barrier for foam plasticsNFPA 285 Multi-story test for high rise bldgs.FM 4450 RoofsFM 4880 Exterior wall,large scale corner,April 2011,Exterior Walls buildings of any height-1,Fire Resistance-where the wall is required to have a fire resistance rating(special cases like separation from another living space or being close to another structure)the wall assembly must pass the ASTM E 119 test for the time rating desired/required,e.g.,1 hour or 2 hours.Thermal Barrier-any foam plastic must be separated from the building interior by a 15 min.thermal barrier as defined in the code.Potential heat Must not be more than 22.7 MJ/m2(2,000 BTU/lb)for siding backer board(PU),April 2011,Exterior Walls buildings of any height-2,Flame spread Foam plastic insulation must have an ASTM E 84 Class A ratingMulti-story test A wall assembly must be tested to and pass NFPA 285.Ignition behavior Wall assemblies must not exhibit sustained flaming when tested to NFPA 268.But there are exceptions for walls that are well protected on the outside see code language,for example a cement coating.,April 2011,Roofs,Foamed plastic must meet ASTM E 84 as at least a Class B material.A 15-min.approved thermal barrier must be used to separate the insulation from the building interior.The roof assembly must have a rating of Class A,B,or C when tested to ASTM E 108.Frequently for commercial buildings a Class A rating is desired.,April 2011,Special Approval,Manufacturers who believe they have construction assemblies that meet the intent of the code but may not pass an individual required test may receive a“Special Approval”if that assembly passes a full scale test such as NFPA 286,FM 4880,UL 1040,or UL 1715.Such testing must be related to the actual end use configuration.,April 2011,Examples of nfpa 285 wall assembliesfrom dow website,April 2011,ICC/IBC Approved Acceptance Criteria and Evaluation Service Reports,April 2011,Icc special acceptance for proudcts,International code council(ICC)Accpetance criteria for products,ICC issues these in cases where products may not exactly meet published code standards or where the code is not specific enoughThey are developed in ICC-ES(Evaluation Service)with a company producing productThey usually cover a product group as opposed to an individual specific product,April 2011,ICC-ES Acceptance Criteria,AC04-SANDWICH PANELSAC12-FOAM PLASTIC INSULATIONAC142-FOAM PLASTIC INSULATION APPLIED DIRECTLY TO STEEL DECKSAC181-RIGID CELLULAR POLYURETHANE PANELSUSED AS EXTERIOR AND INTERIOR WALL CLADDINGAC309-FOAM-IN-PLACE POLYURETHANEFOAM PLASTIC CORE DOORS WITH FIBERGLASS FACERSAC377-SPRAY-APPLIED FOAM PLASTIC INSULATIONSee this link to view the AC12 requirements:http:/www.icc-es.org/criteria/dsp.cfm?ac_code=AC12For an example of an ESR for spray PU foam see:http:/www.icc-es.org/reports/pdf_files/ICC-ES/ESR-2642.pdf,April 2011,Primary Fire/Flammability Tests used in U.S.building codes,April 2011,ASTM E84-(steiner tunnel test)-1,Test results Flame spread index(FSI)based on time and distance the flame front travels and the smoke developed index(SDI)measured opticallyFSI=0 for inert board and SDI=100 for red oakThree classes of materials:Class A:0 FSI 25 and SDI 450Class B:26 FSI 75 and SDI 450Class C:76 FSI 200 and SDI 450,April 2011,ASTM E84-2,April 2011,ASTM E84-4,April 2011,Furnace end view,Actual test apparatus,NFPA 268-1(Ignitability of exterior wall assemblies),Evaluates the propensity of ignition of an exterior wall assembly Applies to exterior wall assemblies having planer or nearly planer,external surfacesAddresses the problem of fire spread from one building to an adjacent building due to radiant ignition of combustible exterior facades by specifying a minimum distance to the property lineIgnition threshold must be equal to or higher than woodFailure if sustained flaming after the 20 min.ignition period,April 2011,NFPA 268-2,April 2011,NFPA 285 1 Fire Propagation of exterior non-load bearing walls containing combustible components,This is only for wall assemblies,also called the Intermediate Multi-Story Test,a large scale testOne of the most important for PU containing insulation walls required for high rise bldgs.Sample one,4.06 m x 5.33 m high assemblyIgnition two gases burners,Bottom room(up to 904 kW),Window(up to 398 kW)Time 30 min.No excessive flaming,April 2011,Nfpa 285 2 Apparatus and Burners,April 2011,Examples of nfpa 285 wall assembliesfrom dow website,April 2011,ASTM E119 1(for fire resistance),Where walls are required to have a fire-resistance rating,data based on E119 tests must be provided to substantiate that they have the rating claimed,e.g.,15 min.,30 min.,1 hour,2 hours.Test duration Varies,but 15 min.for most insulated wall assemblies,bldg.partitions are usually 1 or 2 hoursResult Average temperature rise 130oC of unexposed side after 15 min.,April 2011,Astm E119 2(thermal barrier example),April 2011,NFPA 285 Thermal Barrier,New in 2012 IBC code(Chapter 26)is the use of NFPA 285 to qualify a thermal barrierPart 1 of test is similar to E119,but no PU foamPart 2 of test can be one of the following room or corner tests:NFPA 286,UL 1715,UL 1040,or FM 4880Part 2 is a wall assembly with plastic foam insulation behind the thermal barrier,April 2011,ASTM E108 1(for roof assemblies),There are three part of this test:Burning brand test(burn through)Intermittent flame test(burn through)Spread of flame test(surface burning)As an example,the burning brand test has 3 different sized wood“cribs”or ignition sources,April 2011,ASTM E108 burning brand test,April 2011,E108 Test Failure,