fire performance of concrete structures - nrmca national

Balanced Code Provisions for Residential Structures,Alliance for Concrete Codes and Standards (ACCS)Presented By:,Alliance for Concrete Codes and Standards (ACCS),American Concrete InstituteAmerican Concrete Pipe AssociationAmerican Society of Concrete ContractorsArchitectural Precast AssociationConcrete Foundation AssociationConcrete Reinforcing Steel InstituteInsulating Concrete Form Association,National Precast Concrete AssociationNational Ready Mixed Concrete AssociationPost-Tensioning InstitutePortland Cement AssociationPrecast/Prestressed Concrete InstituteTilt-up Concrete AssociationWire Reinforcing Institute,Introduction,OutlineFire LossBuilding CodesBalanced DesignBenefits of Concrete in FireCosts Associated with Concrete ConstructionTake Action!Conclusions,Limitations to the Building Code,Recent building code revisions have reduced the use of passive fire protection and provided an over-reliance on active fire protection system sSprinkler trade-offs: the concept of exchanging established passive fire containment code provisions for active protection Sprinkler system reliability unknown,What is fire safety?,Fire safety is a component of Building Safety. It concerns safety measures to prevent the effects of fires and is the result of proper use of fire protection measures.,Fire Loss in the United States,Fire loss,Fire Loss,More than 4,000 people die in fires each year, with one death every 130 minutes. Fire kills more Americans than all natural disasters combined. Approximately 85 percent of fire deaths occur in homes. Fire strikes approximately 86,500 apartments, 2,000 hotels and motels, and 740 dormitories annually. Each year, fire departments are called to more than 1.7 million fires, with a fire call received every 18 seconds. There are nearly 510,000 structure fires each year, with one occurring every 62 seconds. Fire causes more than $11 billion in property damage each year, with about $9.5 billion resulting from structure fires. Half of the total property damage occurs in residential properties.,Building and Fire Codes,Building and Fire Codes are state or jurisdiction specificCodes are the minimum requirements “the basement”,Building and Fire Codes,What is a Building Code?A building code is the minimum acceptable standard used to regulate the design, construction, and maintenance of buildings for the purpose of protecting the health, safety, and general welfare of the buildings users.,Up To Date Building Codes,Build safe buildingReduce deaths, injuries and property damagePreserve the built environmentReduce public and private disaster aidMaintain employment and businesses Level playing field for engineers, builders and suppliersProvide economies of scaleMaintain quality of life and property values,Building and Fire Codes,Insert Building and Fire Code information for location being presented,Balanced Design,Balanced design re-established the importance of passive design, including compartmentalization, in combination with active design, to deliver a more comprehensive fire protection system.Active Fire Protection: Fire protection systems that must beactivated to perform, such as sprinklers and smoke detectors.Passive Fire Protection: Fire resistance provided by elementsthat inherently resist fire, such as non-combustible precastconcrete, concrete and masonry block.Balanced Design: A Combination of active and passivedesign elements, as well as the concept ofcompartmentalization, to greatly enhance fire protection at aminimum cost.,Balanced Design,TotalFire Protection,ActiveFire Protection,PassiveFire Protection,Balanced Design,Active Fire ProtectionSmoke detectorsSprinklersDuct detectorsFire alarms,Passive Fire ProtectionFire rated wallsFire rated floorsFire rated separations,Role of Compartmentation,Compartmentation acts to contain fires to a specified area of the building or structureWithout compartmentation, fire may spread from one room or building to a another,Role of Sprinklers,Fire Sprinklers act to extinguish a fire after a specified temperature is achieved in the upper gas layer,Role of SprinklersNFPA standards,NFPA 13 Standard for the Installation of Sprinkler SystemsNFPA 13D Standard for the Installation of Sprinkler Systems in One- and Two-Family Dwellings and Manufactured HomesNFPA 13E Recommended Practice for Fire Department Operations in Properties Protected by Sprinkler and Standpipe SystemsNFPA 13R Standard for the Installation of Sprinkler Systems in Residential Occupancies up to and Including Four Stories in Height,Why sprinklers may fail,Natural Events (earthquake, tornado, etc.)Terrorist EventsInadequate water pressureHuman ErrorLack of maintenanceInstallation ErrorWrong sprinkler for occupancy/fireCoverage IssuesBuilding under constructionOther,Options for Non-combustible construction,cast-in-placehollow-core precastconcrete floors, ceilings, and roofs cast-in place concreteprecast concreteConcrete masonry walls,Advantages of Non-combustible construction for owners/developers,Speed of constructionFaster sales and re-salesLower operating costsLower insurance costsLower maintenance costsLower energy costsCommunity acceptance,Lowest life-cycle costsHigher appreciationAttracts quality oriented occupantsAppeals to investorsProven performanceResistant to seismic and high wind damage,Advantages of Non-combustible construction for occupants,Fire safe non-combustible constructionDoes not burnDoes not produce smoke, fumes or gasesDoes not add fuel to the fireProvides minimum two-hour separation between units,Serves passively for the life of the buildingLower insurance costsNeeds no testing or inspectionNo bouncy or creaky floorsSuperior acoustic qualitiesSecurity for occupants and contents,Advantages of Non-combustible construction for communities,Lower risk and exposure for the fire serviceMore efficient use of fire servicesConstruction does not add fuel to the fireFire is containedAdjacent units are protected,Structural collapse is unlikelyProvides quality community asset for many decadesCommunity recognized for its fire safe constructionProvides a stable tax base for the communityAttracts long term investors to the community.,Fire Containment,Fire Containment is the last line of defense should sprinklers failTo be effective, walls and floors/ceilings providing compartmentation should be of non-combustible construction with at least 2 hours of fire resistance.,Firefighter Safety,A concrete structure can utilize fire rated concrete walls to create compartmentation. The combination of concrete columns, beams, flooring, ceiling and wall elements breaks up each levels space into smaller, self-contained modules that minimize the chance of fire spreading to adjacent unitsThe containment of fire in these small spaces makes entry safer for the firefighter and maintains that building collapse is rare,Fire Resistance,Concrete has history of good performance in fireConcrete is non-combustible and has low thermal conductivityConcrete maintains cool inner core during many fires which maintains load,Fire Resistance,Structural Design LoadLive Load + Dead Load + FIREGoal of Fire Resistance StructuresMaintain structural stabilityReduce spread of fireExperience total burnout without collapse,Concrete at elevated temperatures,250 420 C: Some spalling occurs300 C: Loss of strength begins550 600 C: Cement based materials experience creep and lose their load bearing capacity600 C: Greater than this temperature, concrete is not functioning at its full structural capacity900 C: Temperature of Flame,Fire Resistance,The term fire-resistance designates the ability of a laboratory-constructed assembly to contain a fire in a carefully controlled test setting for a specified period of time.,Harmathys Rules of Fire Endurance,ACI 216,ACI 216.1-97: Standard Method for Determining Fire Resistance of Concrete and Masonry Construction Assemblies,ACI 216,Determines Fire Resistance through one of four methodsQualification by TestingCalculated Fire ResistanceApproval through Past PerformanceEngineered Analysis,Qualification by Testing,The most common test method for determining fire resistance in the United States is the ASTM Standard E 119 Test Methods for Fire Tests of Building Construction and Materials.,ASTM E119,Three End Points to fire test:Ignition of cotton waste supported on the member surface that is away from the surface directly exposed to fire. A temperature increase of 325 F at any point or 250 F on average on the unexposed surface (the heat-transmission end point). Inability to carry the applied design load (i.e., structural collapse).,ASTM E119,Insert video,Calculated Fire Resistance,The fire resistance associated with an element or assembly shall be deemed acceptable when established by the calculation procedures in ACI 216Plain reinforced concrete bearing and non-bearing walls, floors and roof slabs shall conform with the minimum thickness provided in ACI 216 Table 2.1,Calculated Fire Resistance,ACI 216.1-97 Table 2.1. Fire Resistance of singular layer concrete walls, floors, and roofs,Effect of Aggregate,The choice of aggregate directly impacts the performance of concrete during a fire,Wood Fire,Fire Resistance of Wood is significantly lower than that of concrete,Fire Resistance,Strength at elevated temperatures,Fire Spread,Concrete will not ignite. The fires spread is slowed and its damage is minimized. This ability to resist fire creates more time for detection, evacuation and suppressionthe three key ingredients for minimizing damage and injury during a fire.,Flame Spread,Concrete will limit flame spread,Interior Finish,The majority of fire deaths in a residential home is due to toxic products of combustion from interior finish,Toxicity,Most fire deaths result not from heat or burns but from inhaling smoke and toxic gasses.Gases produced in a fire include: water, CO2, styrene, bromide, and COConcrete does not produce toxic gases when involved in a fireCompartmentation with concrete construction reduces the spread of toxic gas or smoke.,CostsFSCAC Cost Comparison Study,Conventional wood framing with wood floor system (Type V-B Construction)Conventional wood framing with wood floor system (Type V-A Construction)Light gauge steel framing with cast-in-place concrete floor system on metal form deckInsulated concrete form exterior walls with interior bearing walls constructed ofconcrete masonry units and precast concrete floor system,Load bearing concrete masonry with precastconcrete floor systemLoad-bearing concrete masonry with cast-inplaceconcrete floor systemPrecast concrete walls with precast concrete Floor systemInsulated concrete form walls with precast concrete floor systemInsulated concrete form walls with cast-inplace concrete floor system,The building construction types, designed using the provisions of the 2003 International BuildingCode, included:,Cost Study Results,The study provides the relative cost as a comparison to wood frame as a baseline of 100%, indicating increases or decreases relative to the baseline. Cost percentages shown below are examples of those provided by the complete study.,Insurance Benefit,With increased emphasis on risk avoidance in the insurance industry, property insurers and risk insurance managers have noticed the fire-resisting advantages offered by non-combustible construction,Source: Concrete & Masonry Industry Firesafety Committees Fire Protection Planning Report No. 9,Ensure safer Buildings through code adoption,Adopt a model building code which supports the concept of balanced designEnsure building code does not depend fully on active fire protection systems or incorporate the idea of “sprinkler trade-offs”Support amendments to the code which allows for adequate passive fire protection designConsider using concrete in the building design to provide excellent fire resistant construction,708.3 Fire-resistance rating. Fire partitions shall have a fire-resistance rating of not less than 1 hour.Exceptions: 1. Corridor walls as permitted by Table 1017.1.2. 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