Ch. 4
A material that is weak in tension is: (2)
Weak in shear and bending
A 20 ft-high column shortens by 0.6 in. under a load. What is the resulting strain in the column?
0.0025
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?
125 psi
What is the yield stress of A36 steel?
36 ksi
Which gives greater warning before failure: a brittle material a ductile material
A ductile material
The units of modulus of elasticity are:
psi ksi pa gpa
Concrete is:
An elastic material
Low carbon (mild) steel is:
And elastic-plastic material
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 ______ strength.
Compressive
The test specimen used for determining the compressive strength of concrete in the united states is a:
Cylinder measuring 6 in. diameter x 12 in. high
In most materials, the safety margin for compressive stress and bending stress is the same.
False.
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.
Which of the following beam cross-sections are structurally more efficient in bending? Rectangular (solid) section I-section
I-section
The allowable stress in a material is generally:
Less than its ultimate stress.
In relation to its compressive strength, the tensile strength of concrete is:
Much lower
In a simple three-member truss consisting of two rafters and a tie, each member is in:
Shear
Modulus of elasticity refers to how
Stiff a material is.
In a suspension bridge, which of the member(s) is (are) in compression?
Support Pylons
In a typical stress-strain diagram of a material, the stress is generally plotted along the vertical axis.
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
Which of the following beam cross-sections is structurally more efficient in bending? Rectangular (solid) section Tubular section
Tubular
When we determine the strength of concrete using the test specimens, we determine the concrete's:
Ultimate compressive stress.
The bending stresses along the neutral axis of a beam are:
Zero
When a cable or rope is compressed by a force, what is the compressive stress in it?
Zero
The primary purpose of ties in a reinforced concrete column is to prevent:
the buckling of vertical reinforcement in column.
The stirrups in a reinforced concrete beam are used to increase:
the strength of beam in shear.