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