Building construction materials 2
The U value and R-value f an assembly are related to each other by which relationship?
(U)(R) = 1.0
The emissivity of a material lies between
0 and 1
a 20 ft. high column shortens by 0.6 in. under a load. what is the resulting strain in the column?
0.0025
In a building whose structural system consists of columns, beams, and floor and roof slabs, the columns are spaced at 40 ft on center in one direction and 25 ft on center in the other direction. what is the tributary area for an interior column?
1,000 ft^2
the design wind speed for a location is the peak
3-s gust speed
a reinforced concrete beam measures 12 in. X 24. in cross section. if the density of reinforced concrete is 150 lb/ft^3, the weight of the beam is
300 lb/ft
the total approximate gravity load on a floor in a typical wood frame residential building is
50 psf
Which gives greater warning before warning before failure?
A ductile material
Apart from the climate of the location, the other factors that affect energy-conscious building design are
All of the above
Which of the following insulating materials contain HCFC gas within their voids?
All of the above
concrete is
An elastic material
Low-carbon (mild) steel is
An elastic-plastic material
Which of the following steel stud wall assemblies gives a higher overall R-value? in both assemblies, the total amount of insulation is R-15
Assembly A has an exterior insulating sheathing of R-5 and within-stud insulation of R-10
In which of the following locations is blown insulation most commonly used?
Attic spaces
Within an air space (cavity), the mode of heat transfer is primarily by
Both convection and radiation
The unit for the measure of energy in the US system of units is
Btu
the test specimen used for determining the copressive strength of concrete in the US is a
Cylinder measuring 6 in. in diameter 12 in. high
Which of the following plastic foam insulation contains air within its voids?
Expanded Polystrene (EPS) board (bead board)
With respect to wind pressure, a building site is classified in terms of
Exposures B, C, and D
Which of the following insulating materials is available in the form of rigid boards?
Extruded Polystyrene
Which of the following insulations is combustible?
Extruded Polystyrene (XPS) board
A building assembly with a higher U-value is thermally more insulating than one with a lower U-value. T or F?
False
Air is a good thermal insulator, provided that it exists in large volumes. T or F?
False
An average tornado strikes a larger area on the ground than a hurricane. T or F
False
For wind blowing along one of the two major axes of a rectangular building, the side walls are subjected to positive (toward the wall pressure). T or F
False
in most materials, the safety margin for copressive stress and bending stress is the same. T or F?
False
Which of the following insulating materials is available in the form of batts?
Fiberglass
For the same thckness, which of the following materials has the smallest R-value?
Gypsum
Which of the following materials has the smallest value of emissivity?
Highly polished metal
Which of the following beam cross sections is structurally more efficient in bending?
I-section
in a suspension bridge, which member(s) is (are) in compression?
Support Pylons
according to the geologists, the earth's surface is composed of several segments that are called
Tectonic plates
Highest wind speeds are usually obtained in.
Tornadoes
Everything else being the same, a building constructed of heavyweight materials is subjected to a greater earthquake load than a building constructed of lightweight materials
True
For wind blowing along one of the two major axes of a rectangular building, the windward wall is subjected to positive (toward the wall pressure). T or F
True
Insulating materials that contain HCFC gas within their cells have a higher R-value than those that contain air within their cells. T or F?
True
Like color, emissivity is a property of the surface of the material, not of the entire body of the material. T or F?
True
The primary purpose of longitudinal steel bars in a reinforced concrete beam is to overcome the weakness of concrete in tension. T or F?
True
in a typical stress- strain diagram of a material, the stress is generally plotted along the vertical axis. T or F?
True
the stress-strain diagram of mild steel is nearly a straight line up to the yield point. T or F?
True
the use of aluminum foil in attics is more useful in warm climates than in cold climates. T or F?
True
Which of the following beam cross sections is structurally more efficient in bending?
Tubular Section
When we determine the strength of concrete using the test specimens, we determine the concrete's
Ultimate compressive stress
A material that is weak in tension is
Weak in bending
a material that is weak in tension is
Weak in shear
the region of the US that is relatively more earthquake prone is the
Western US
When a cable or rope is compressed by a force, what is the compressive stress in it?
Zero
The design snow load on a roof is a function of
all of the above
The unit of modulus of elasticity
all of the above
the design wind speed is also referred to as the
basic wind speed
The horizontal blocking in wood studs helps prevent
buckling of studs
The material in an arch is primarily in
compression
The bearing strength of a material is closely related to its
compressive strength
Within a solid, the mode of heat transfer is by
conduction
in a simple three-member truss consisting of two rafters and a tie, each member is in
either tension or compression
A wet or moist material provides a higher R-value than if the same material is dry. T or F?
false
For wind blowing along one of the two major axes of a rectangular building, the Leeward wall is subjected to positive (toward the wall pressure). T or F
false
in relation to its compressive strength, the tensile strength of concrete is
much lower
An earthquake measuring 7.0 on the Richter scale is
none of the above
the bending stresses along the neutral axis of a beam are
zero
IECC is an acronym for
International Energy Conservation Code
The approximate R-value of an air space in a wall is
R-1
The R value of a building assembly in the SI system is referred to as the...
RSI-value
A rectangular column measuring 12 in X 12 in. in cross section carries a load of 18 kips. what is the stress in the column?
None of these
The R-value of a building assembly is influenced by the inside and outside air films. the sum of the R values of these two films (Rsi =Rso) is approximately equal to
1.0
The R-value of a single glass sheet, including the film resistances, is approximately
1.0
the total approximate dead load of a floor in a typical wood frame residential building is
10 psf
For most of the United States, the design wind speed for an average-risk building is
115 mph
In a building whose structural system consists of columns, beams, and floor and roof slabs, the columns are spaced at 40 ft on center in one direction and 25 ft on center in the other direction. what is the tributary area for a corner column?
250 ft^2
The stirrups in a reinforced concrete beam are used to
Increase the strength of the beam in shear
The concept of 'aged R-value' is applicable to
Insulating materials that contain HCFC gas
on a leeward wall, the wind pressure
Is almost constant with height above ground
The unit for the measure of energy in the SI system of units is
Joule
the allowable stress in a material is generally
Less than its ultimate stress
Aluminum foil is commonly used in building assemblies because it
Lowers the heat transfer due to radiation
The R value of a 2 in.-thick material is 4.0. what is the R-value of the same matierial if its thickness is 1 in.?
None of these
For the same thckness, which of the following materials has the highest R-value?
Polyisocynurate
The primary purpose of ties in reinforced concrete column is to
Prevent the buckling of vertical reinforcement in the column.
The approximate R-value of an air space in a wall with an aluminum foil lining is
R-2.5
A wall assembly (total area = 100ft^2) consists of 80ft^2 of opaque wall with an R-value of R-20 and a 20ft^2 of window whose R-value is R-2. the effect (overall) R-value of the entire wall assembly is approximately
R-7
The number of mild (minor to very minor) earthquakes occurring on the earth is almost
Several thousand per year
In a steel column that rests on a concrete footing, the area of the bearing plate used is generally
greater than the cross sectional area of the column
When an aluminum foil is used in attic spaces, is is
laminated to inside facing surface of roof sheathing
Foamed concrete is generally used as insulation in
none of the above
One of the main reasons for using HCFC gas in some insulating materials is that it
none of the above
the design wind speed for an average-risk building at a location has a probability of occurrence of once in _________ years.
none of the above
The R-value of a 1 in. thick extruded polystyrene board is 5.0. if the R-value of a 1 in. thick brick wall is 0.2, how thick should the brick wall be to equal the R-value of 1 in. thick extruded polystyrene?
none of these
What is the yeild stress of grade 60 reinforced steel?
none of these
the modulus of elasticity refers to how
stiff a material is