Construction Materials Test 2
In building whose structural system consists of columns, beams, and floor and roof slabs, the columns are spaced at 40ft on center in one direction and 25ft on center in the other direction. what is the tributary area for an interior column?
1,000ft^2
The total approximate dead load of a floor in a typical wood frame residential building is
10psf
For most of the United States, the design wind speed for an average risk building is
115mph
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?
250ft^2
The design wind speed for a location is the peak
3-s gust speed
A reinforced concrete beam measures 12inx24in in cross section. If the density of reinforced concrete is 150lb/ft cubed, 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
30psf
The floor live load in a residential occupancy is generally assumed to b
40psf
The material in an arch is primarily in-
A Compression
The emissivity of a material lies between?
A. 0 and 1
Concrete is-
A. A plastic material
Within a solid, the mode of heat transfer is by?
A. Conduction
A.In a steel column that rests on a concrete footing, the area of the bearing plate is generally-
A. Greater than the cross-sectional area of the column
The primary purpose of ties in a reinforced concrete column is to-
A. Prevent the buckling of vertical reinforcement
The approximate R-value of an air space in a wall is?
A. R-1
21The primary purpose pf longitudinal steel bars in a reinforced concrete beam is to overcome the weakness of concrete in tension. (T/F)
A. True
In a typical stress-strain diagram of a material, the stress is generally plotted along the vertical axis. (T/F)
A. True
Like color, emissivity is a property of the surface of the material, not of the entire body of the material. True or False?
A. True
The stress-strain diagram of mild steel is nearly a straight line up to the yield point. (T/F)
A. True
When we determine the strength of concrete using the test specimens, we determine the concrete's-
A. Ultimate compressive stress
The design snow load on a roof is a function of
All of the above
The R-value of a 2 in. thick material is 4.0. What is the R- value of the same material if its thickness is 1 in.?
B. 2 in.
Which gives greater warning before failure?
B. A ductile material
In most materials, the safety margin for compressive stress and bending stress is the same. (T/F)
B. False
Which of the following beam cross sections is structurally more efficient in bending ?
B. I-section
The concept of aged R-value is applicable to?
B. Insulating materials that contain HCFC gas
The unit of the measure of energy in the SI system is the?
B. Joule
The allowable stress in a material is generally-
B. Less than its ultimate stress
Modulus of elasticity refers to how-
B. Stiff a material is
Which of the following beam cross sections is structurally more efficient in bending?
B. Tubular Section
A material that is weak in tension is- (bending)
B. Weak in bendine
A material that is weak in tension is- (shear)
B. Weak in shear
Low-Carbon (mild) steel is-
C. An elastic-plastic material
The unit for the measure of energy in the U.S. system of units is the?
C. Btu
The bearing strength of a material is closely related to its-
C. Compressive strength
In a simple three member truss consisting of two rafters and a tie, each member is in-
C. Either tension or compression
Aluminum foll is commonly used in building assemblies because it?
C. Lowers heat transfer due to radiation
For the same thickness, which of the following materials has the highest R-value?
C. Polyisocyanurate
In a suspension bridge, which member(s) is(are) in compression?
C. Support pylon
The bending stresses along the neutral axis of a beam are-
C. Zero
When a cable or rope is compressed by a force, what is the compressive stress in it?
C. Zero
A 20-ft-high column shortens by .6 in. under a load. What is the resulting strain in the column?
D. 0.0025 (no units)
The R- value of a single glass sheet, including the film resistances is nearly?
D. 1
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?
D. 1.0
A rectangular column measuring 12in X 12in in cross section carries a load of 18 kips. What is the stress in the column?
D. 125psi
(Start of Ch. 5) Apart from the climate of the location, the other factors that affect energy-conscious building design are?
D. All of the above (building orientation and building shape, building envelope, and site conditions)
Which following insulating materials contain HCFC gas within their voids?
D. All the above (extruded polystyrene, polyisocyanurate, and polyurethane)
Which of the following events provided a major push toward energy-conserving building design?
D. Arab-Israeli war of 1973
The horizontal blocking in wood studs helps prevent-
D. Buckling of studs
Which of the following materials has the smallest value of emissivity?
D. Highly polished metal
In relation to it's compressive strength, the tensile strength of concrete is-
D. Much lower
The approximate R-value of an air space in a wall with an aluminum foil lining is?
D. R-2.5
The R-value of a building assembly in the SI system is referred to as the?
D. RSI value
The stirrups in a reinforced concrete beam are used to-
D.Increase the strength of the beam in shear
The R-value of a single glass sheet, without considering the film resistances, is approximately?
E. 0
The units of modulus of elasticity are-
E. All of the above (A. psi, B. ksi, C. Pa, D. GPa)
Within an air space (cavity), the mode of heat transfer is primarily by?
E. Both Convection and Radiation
The test specimen used for determining the compressive strength of concrete in the United States is a-
E. Cylinder measuring 6in in diameter X 12in high
For the same thickness, which of the following materials has the smallest R- value?
E. Gypsum
What is the yield stress of grade 60 reinforced steel?
E. None of the above (A. 60 lb, B. 6,000 lb, C. 6,000 psi, D. 60 psi)
One of the main reasons for using HCFC gas in some insulating materials is that it?
E. 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?
E. none of the above (25 in. thick)
With respect to wind pressure, a building site is classified in terms of
Exposures B, C, and D
A wet or moist material provides a higher R-value than if the same material was dry. True or False?
False
Air is a good thermal insulator provided that it exists in large volumes. True or False?
False
Insulating materials that contain HCFC gas within their cells have higher R-value than those that contain air within their cells. True or False?
True
The design wind speed is also reffered to as the
basic wind speed
Which of the following loads can be estimated with the greatest certainty
dead loads
An average tornado strikes a larger area on the ground than a hurricane true/false
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. true/false
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. true/false
false
Roof live load is a function of the building's occupancy true/false
false
The two main categories under which all building loads may be classified are
gravity loads and lateral loads
On a leeward wall, the wind pressure
is almost constant with height above the ground
The loads on a column are generally expressed in
lb
The loads on a beam are generally expressed in
lb/ft
The loads on a floor are generally expressed in
lb/ft^2
The roof live load of a building is generally
less than the floor live load
Which of the following occupancies has the highest floor live load?
library stack rooms
An earthquake measuring 7.0 on the Richter scale is
none of the above
The design wind speed for an average-risk building at a location has a probability occurrence of...
none of the above (500 years)
In which of the following roofs will you consider the effect of rain load?
roof with a parapet
The number of mild (minor to very minor) earthquakes occurring on the earth is almost
several thousand per year
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/false
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. true/false
true
The region of the United States that is relatively more earthquake prone is the
western united states