5 Building Construction Materials And Structural Systems Flashcards
Wood is stronger in the direction parallel to the grain than
Than against the grain
The strength of Wood is affected by its
Moisture content
Most structural wood has a moisture content of
19% or less
Boards have a nominal thickness of
2 inches or less
Dimensional lumber has a nominal thickness of
2-4 inches
Timbers have a nominal thickness of
5 inches or more
Two main methods of fire retardant treatment of wood
Pressure impregnation and surface coating
Surface coating wood is used to reduce the surface burning of wood
T F
True
Any of the following chemicals may be used and pressure treatment of wood
Ammonium phosphate. Boric acid. Ammonium sulfate. Ammonium phosphate. Zinc chloride. Sodium dichromate
Typical reduction in strength from fire retardant lumber
10-20%
Oldest and most simplistic type of building material
Masonry
Most common size of concrete block
8 x 8 x 16”
The principal types of stone used in construction are
Granite, limestone, sandstone, slate, marble
Clinker
Stony matter fused together by heat
Superplasticizer
Can be used as an admixture to make concrete flow more freely
The overall fire resistance of steel reinforced concrete depends on
The depth of cover of the concrete over the steel and the quality of the concrete
Single most important factor in determining the ultimate strength of concrete is
Water to cement ratio
Disadvantages of steel
Rust
weakening from heat
The quickness with which unprotected steel fails when exposed to fire depends on several factors
Massive steel members.
Intensity of exposing fire.
Load supported by steel.
Type of connections used to join steel members
When Exposed to heavy fire conditions compared to heavy steel beams and girders, slender or lightweight steel members tend to fail
Sooner than heavier members
In order to use steel and fire resistive designs it must be protected from the heat of the fire by
Fire resistant coating
In old buildings the steel framework was encased in brick or masonry. He still call them encased in 3 inches of concrete would have a fire resistance rating of
Four hours
Materials that can be used to fireproof steel include the following
Metal lath and plaster.
Gypsum board.
Spray on coating.
Mineral and fiberboard
Sprayed on coatings are especially popular when appearance is not important. They have densities ranging from
12-40 pounds per cubic foot
Fire damper
Device installed in here talked to penetrate fire resistant rated vertical or horizontal assembly. The transfer of heat or flame through duct
Aluminum has a melting point of
1220°F
Cast-iron tends to fail by fracturing rather than what as in the case of steel
Yelding
Heat strengthened glass
Surface compression between 3500 psi and 10,000 PSI
Fully tempered glass
Service compression in excess of 10,000 PSI
Fully temper glass is used in windows that may be subject to Highwind forces and Exterior doors that
People might walk into accidentally
Glassblock is generally how thick
2-4 inches
Glassblock is typically available in sizes ranging from
6 x 6”-8 x 8”
True/false glassblock is a fire resistant material
False
Glassblock alone can be substituted for a fire rated wall true false
False
The maximum allowable area for one piece of wire glass one quarter of an inch thick is
1296 in.²
Fire rating duration of wire glass when used in a listed fire door or window frame
45 minute rating
The maximum allowable area of wire class and a 90 minute fire door is
100 in.²
Fire rated glass
Does not use wires. Made from a combination of glass and plastic
A 45 minute reading can be obtained from fire rated glass for panels as large as
3325 in.²
Pony wall
Non-loadbearing wall less than 36 inches tall
For glass that requires a reading of up to two hours what can be used
Heat strengthened or tempered glass with a special sprinkler to spray on it
For a rated piece of glass that requires sprinkler protection to keep it cool height of the protective glass panel is limited to what
13 feet high with a 36 inch pony wall at the base of the glazing
Slurry
Suspension formed by a quantity of powder mixed into a liquid in which the solid is only slightly soluble
Process that heats a substance to a high temperature below the melting refusing point causing lots of moisture
Calcined
Assemblies using gypsum board can have a fire resistance rating from
1-4 hours
Type X gypsum board
Used in fire rated assemblies reinforced by glassfiber
Type C gypsum board
Used in fire rated assemblies
Core board
Used for shaft walls and solid partitions
Gypsum board is available in thicknesses ranging from
1/4 to 3/4 inch
1 inch gypsum board is used only for
Core board
Type C gypsum board contains what substance that expands as it is exposed to heat
Vermiculite
Type of plastic that will not softener or melt when reheated
Thermosetting plastic
Synthetic material made from the polymerization of organic compounds to become soft when heated and hard when cooled
Thermoplastic
Examples of thermosetting plastics are
Vulcanized rubber and Bakelite
Plastics are organic materials true false
True carbon-based even though not naturally occurring
The combustion of vinyl chloride produces what type of gas
Hydrogen chloride, the gaseous form of hydrochloric acid
Building codes require a thermal barrier of how thick of gypsu wallboard to separate plastic from interior of building
Half inch thick
Automatic sprinklers are required in addition to a thermal barrier when foam plastic is used in thicknesses greater than what
4 inches
Basic properties of building materials that are shared
Combustibility. Thermal conductivity. Rate of thermal expansion. Variation of strength with temperature
A fabric roof on the membrane structure weighs
About 2 pounds per square foot
The materials used in membrane structures must be
Noncombustible
Primary advantage of precast concrete is
Quality control
Ledges the project out from the column and support a beam that are cast into the column
Corbels
Flat slab cast in place
Simple system that consists of a slab of concrete supported by concrete columns thicknesses ranging from 6-12 inches
Concrete floor slab 8 inches thick the rest on columns 22 feet apart requiring no additional reinforcement
Flat plate
Flat slab floor is typically make use of columns with reinforcement at the top of the column which are known as
Drop panels, concrete rectangle on the top of the panel for support. Mushroom capital, flare at the top of the column
Rigid beam and girder frame
Resist bending forces from supported loads and lateral forces
Semi rigid steel frame
Not completely rigid bracing or sheer panel may be needed
Simple steelframe
Joints are designed primarily to support a vertical force
Open web joist can usually be 6 feet deep and up to 144 feet span, however they are more frequently found out what size
2 feet deep and 40 foot span
Steel structural members used to take the place of steel beams
Joist girder, heavy steel trusses open web
Steel rigid frame is usually are used for spans of what
40-200 feet
Top of a rigid frame building
Crown
Steel rigid frame points where inclined members intersect vertical members are known as
Knees
The thickness of masonry walls varies from
6 inches to several feet
walls constructed with fire rated concrete masonry units or bricks can have a fire resistance of
2-4 hours
Because of its limitations in the basic strength avoid it is not usually economical to use wood frames and buildings taller than
Three stories
And heavy timber design the columns are not less then what size
8 x 8”
In heavy timber design floor beams are at minimum what size
6 x 10”
heavy Timbers from a single log are usually not longer than
20 feet, longer requires glue Lam
The posts and post and beam construction are usually what size
4 x 4” or 6 x 6” spaced 4-12 feet apart
Western-style framing is also known as
Platform framing
Typically the code requires that from insulation be faced with the thermal barrier such as what to prevent or retard service ignition of the phone
Gypsum wallboard
A brick veneer wall must be tied to the wood frame wall at intervals of
16 inches
One frequently use rule is that in brick loadbearing walls every six course of brick is
A header course with the ends of the brick facing out
