Construction Materials Midterm
The typical proper slump for a rammed earth mix is
0"
A #8 reinforcing bar has a diameter of...
1 in.
For most of the United States, the basic wind speed for design is
115mph
A square specimen measuring 12" x 12" in cross section carries a load of 18 kips. What is the stress in the material?
125 psi
The yield strength of prestressing steel is
270 ksi
The compressive strength of concrete is generally measured...
28 days after casting the concrete test specimen
Steel reinforcement in concrete elements exposed to earth such as footings must have a minimum concrete cover of
3"
The time period used in BEES for determining the LCC of a product is
50 years
After concrete has been placed in the form, it should be compacted as much as economically practical.
False
Rammed earth construction requires electrical or pneumatic tamping techniques.
False
Stirrups in a reinforced concrete beam are used to
Increase strength in shear
The allowable stress in a material is generally
Less than its ultimate stress
Stirrups are generally made of
No. 3 or No. 4 bars
The rate at which concrete gains strength increases as the ambient air temperature increases.
True
The most commonly specified type of portland cement is
Type I/II
One of the major US organizations that deals with sustainable architectural design is the
USGBC
Which of the following materials is most renewable?
Wood
Which gives greater warning before failure?
a ductile material
By weight, which of the following materials has the highest embodied energy when made from virgin raw materials?
aluminum
Horizontal blocking for wood studs helps prevent
buckling of studs
The element in concrete with the greatest embodied energy is
cement
What makes Stabilized Rammed Earth stabilized?
cementitious ingredients
The bearing strength of a material is closely related to its
compressive strength
Which of the following loads can be estimated with the greatest certainty?
dead loads
A well-graded coarse aggregate is one in which the size of all aggregate particles is approximately the same
false
According to building codes, plain concrete (without steel reinforcement) is not permitted in new construction
false
Rammed earth exhibits both high thermal mass and insulation qualities.
false
Which of the following materials is a pozzolana?
fly ash
On a leeward wall, the wind pressure
is constant with height above the ground (dependent on other factors)
Which of the following occupancies has the highest floor live load?
library stack rooms
Modulus of Elasticity refers to how...
stiff a material is
The distinction between coarse aggregate and fine aggregate is based on
the aggregate's particle size
Quicklime reacts readily with water
true
The primary purpose of longitudinal steel bars in a reinforced concrete beam is to overcome the weakness of concrete in tension.
true
The stress-strain diagram of mild steel is nearly a straight line up to the yield point.
true
The term "prestressed concrete" refers to both pretensioned and post-tensioned concrete.
true
The author S. Dobson cites the following obstacle to greater acceptance of rammed earth in the US:
trust in the material successful examples of built structures cost competitiveness
The design snow load on a roof is a function of
wind exposure classification of that site, roof slope, ground snow load of the location
The slump of concrete is a measure of the...
workability of concrete
When a cable or rope is compressed by a force, what is the compressive stress in it?
zero