Balanced Code Provisions for Residential Structures Alliance for Concrete Codes and Standards (ACCS) Presented By:
Alliance for Concrete Codes and Standards (ACCS) n n n n American Concrete Institute American Concrete Pipe Association American Society of Concrete Contractors Architectural Precast Association Concrete Foundation Association Concrete Reinforcing Steel Institute Insulating Concrete Form Association n n n National Precast Concrete Association National Ready Mixed Concrete Association Post-Tensioning Institute Portland Cement Association Precast/Prestressed Concrete Institute Tilt-up Concrete Association Wire Reinforcing Institute
Introduction n n n Outline Fire Loss Building Codes Balanced Design Benefits of Concrete in Fire Costs Associated with Concrete Construction Take Action! Conclusions
Limitations to the Building Code n Recent building code revisions have reduced the use of passive fire protection and provided an over-reliance on active fire protection system s ¨ Sprinkler trade-offs: the concept of exchanging established passive fire containment code provisions for active protection ¨ Sprinkler system reliability unknown
What is fire safety? n 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 n 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. n Approximately 85 percent of fire deaths occur in homes. Fire strikes approximately 86, 500 apartments, 2, 000 hotels and motels, and 740 dormitories annually. n 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. n 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 are state or jurisdiction specific n Codes are the minimum requirements – “the basement” n
Building and Fire Codes n 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 building’s users.
Up To Date Building Codes ¨ Build safe building ¨ Reduce deaths, injuries and property damage ¨ Preserve the built environment ¨ Reduce public and private disaster aid ¨ Maintain employment and businesses ¨ Level playing field for engineers, builders and suppliers ¨ Provide economies of scale ¨ Maintain quality of life and property values
Building and Fire Codes n 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. n Active Fire Protection: Fire protection systems that must be activated to perform, such as sprinklers and smoke detectors. n Passive Fire Protection: Fire resistance provided by elements that inherently resist fire, such as non-combustible precast concrete, concrete and masonry block. n Balanced Design: A Combination of active and passive design elements, as well as the concept of compartmentalization, to greatly enhance fire protection at a minimum cost.
Balanced Design Total Fire Protection Active Fire Protection Passive Fire Protection
Balanced Design Active Fire Protection n n Smoke detectors Sprinklers Duct detectors Fire alarms Passive Fire Protection n Fire rated walls Fire rated floors Fire rated separations
Role of Compartmentation n n Compartmentation acts to contain fires to a specified area of the building or structure Without compartmentation, fire may spread from one room or building to a another
Role of Sprinklers n Fire Sprinklers act to extinguish a fire after a specified temperature is achieved in the upper gas layer
Role of Sprinklers NFPA standards n NFPA 13 Standard for the Installation of Sprinkler Systems n NFPA 13 D Standard for the Installation of Sprinkler Systems in One- and Two-Family Dwellings and Manufactured Homes n NFPA 13 E Recommended Practice for Fire Department Operations in Properties Protected by Sprinkler and Standpipe Systems n NFPA 13 R Standard for the Installation of Sprinkler Systems in Residential Occupancies up to and Including Four Stories in Height
Why sprinklers may fail n n n n n Natural Events (earthquake, tornado, etc. ) Terrorist Events Inadequate water pressure Human Error Lack of maintenance Installation Error Wrong sprinkler for occupancy/fire Coverage Issues Building under construction Other
Options for Non-combustible construction n n n cast-in-place hollow-core precast concrete floors, ceilings, and roofs cast-in place concrete precast concrete Concrete masonry walls
Advantages of Non-combustible construction for owners/developers ¨ ¨ ¨ ¨ Speed of construction Faster sales and re-sales Lower operating costs Lower insurance costs Lower maintenance costs Lower energy costs Community acceptance ¨ ¨ ¨ Lowest life-cycle costs Higher appreciation Attracts quality oriented occupants Appeals to investors Proven performance Resistant to seismic and high wind damage
Advantages of Non-combustible construction for occupants n n n Fire safe non-combustible construction Does not burn Does not produce smoke, fumes or gases Does not add fuel to the fire Provides minimum twohour separation between units n n n Serves passively for the life of the building Lower insurance costs Needs no testing or inspection No bouncy or creaky floors Superior acoustic qualities Security for occupants and contents
Advantages of Non-combustible construction for communities n n n Lower risk and exposure for the fire service More efficient use of fire services Construction does not add fuel to the fire Fire is contained Adjacent units are protected n n n Structural collapse is unlikely Provides quality community asset for many decades Community recognized for its fire safe construction Provides a stable tax base for the community Attracts long term investors to the community.
Fire Containment n n Fire Containment is the last line of defense should sprinklers fail To be effective, walls and floors/ceilings providing compartmentation should be of noncombustible 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 level’s space into smaller, selfcontained modules that minimize the chance of fire spreading to adjacent units § The containment of fire in these small spaces makes entry safer for the firefighter and maintains that building collapse is rare
Fire Resistance n n n Concrete has history of good performance in fire Concrete is non-combustible and has low thermal conductivity Concrete maintains cool inner core during many fires which maintains load
Fire Resistance n Structural Design Load ¨ Live Load + Dead Load + FIRE n Goal of Fire Resistance Structures ¨ Maintain structural stability ¨ Reduce spread of fire ¨ Experience total burnout without collapse
Concrete at elevated temperatures n n n 250 – 420 °C: Some spalling occurs 300 °C: Loss of strength begins 550 – 600 °C: Cement based materials experience creep and lose their load bearing capacity 600 °C: Greater than this temperature, concrete is not functioning at its full structural capacity 900 °C: Temperature of Flame
Fire Resistance n 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.
Harmathy’s Rules of Fire Endurance
ACI 216 n 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 methods Qualification by Testing 2. Calculated Fire Resistance 3. Approval through Past Performance 4. Engineered Analysis 1.
Qualification by Testing n 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 E 119 n Three End Points to fire test: 1. Ignition of cotton waste supported on the member surface that is away from the surface directly exposed to fire. 2. A temperature increase of 325 F at any point or 250 F on average on the unexposed surface (the heat-transmission end point). 3. Inability to carry the applied design load (i. e. , structural collapse).
ASTM E 119 n Insert video
Calculated Fire Resistance n The fire resistance associated with an element or assembly shall be deemed acceptable when established by the calculation procedures in ACI 216 n Plain reinforced concrete bearing and nonbearing 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 Aggregate Type Minimum equivalent thickness for fire resistance rating, in. 1 hr 1 ½ hr 2 hr 3 hr 4 hr Siliceous 3. 5 4. 3 5. 0 6. 2 7. 0 Carbonate 3. 2 4. 0 4. 6 5. 7 6. 6 Semilightweight 2. 7 3. 3 3. 8 4. 6 5. 4 Lightweight 2. 5 3. 1 3. 6 4. 4 5. 1
Effect of Aggregate n The choice of aggregate directly impacts the performance of concrete during a fire
Wood Fire Resistance of Wood is significantly lower than that of concrete
Fire Resistance
Strength at elevated temperatures
Fire Spread § Concrete will not ignite. The fire’s spread is slowed and its damage is minimized. § This ability to resist fire creates more time for detection, evacuation and suppression—the three key ingredients for minimizing damage and injury during a fire.
Flame Spread n 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 n Most fire deaths result not from heat or burns but from inhaling smoke and toxic gasses. ¨ Gases produced in a fire include: water, CO 2, styrene, bromide, and CO ¨ Concrete does not produce toxic gases when involved in a fire ¨ Compartmentation with concrete construction reduces the spread of toxic gas or smoke.
Costs FSCAC Cost Comparison Study The building construction types, designed using the provisions of the 2003 International Building Code, included: ¨ ¨ ¨ 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 deck Insulated concrete form exterior walls with interior bearing walls constructed of concrete masonry units and precast concrete floor system ¨ ¨ ¨ Load bearing concrete masonry with precast concrete floor system Load-bearing concrete masonry with cast-inplace concrete floor system Precast concrete walls with precast concrete Floor system Insulated concrete form walls with precast concrete floor system Insulated concrete form walls with cast-inplace concrete floor system
Cost Study Results n 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 n 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 Committee’s Fire Protection Planning Report No. 9
Ensure safer Buildings through code adoption n Adopt a model building code which supports the concept of balanced design ¨ Ensure 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 design ¨ Consider using concrete in the building design to provide excellent fire resistant construction
Example How to adjust existing building code to reduce sprinkler trade-offs 708. 3 Fire-resistance rating. Fire partitions shall have a fireresistance rating of not less than 1 hour. Exceptions: 1. Corridor walls as permitted by Table 1017. 1. 2. Dwelling unit and sleeping unit separations in buildings of Types IIB, IIIB and VB construction shall have fireresistance ratings of not less than 1 /2 hour in buildings equipped throughout with an automatic sprinkler system in accordance with Section rated corridor as required by Section 903. 3. 1. 1
Take Action! n n n Find out which (if any!) building code your state or jurisdiction currently enforces or adopts Research whether the code adequately addresses the ideas incorporated in the balanced design approach Contact your building code official or state representative and submit your concerns Work with local groups for adoption of strict amendments ensuring balanced design and participate in the development of the model code process Educate others on the benefits of concrete construction, passive fire protection and balanced design.
Conclusions n n Adequate building codes with a balanced design approach can provide safe buildings for occupants, owners and fire safety officials Concrete is a non-combustible building material that will n n n Limit flame spread Reduce costs Not produce toxic gases during fire Provide high fire resistance Ensure fire containment Construct at similar costs to other construction methods
Resources n Include links (websites, names, brochure, addresses, etc. )
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