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.