steel Flashcards
1
Q
These shapes are produced in different sizes and are designated with the letters _______.
A
W, HP, M, S, C, MC, L
2
Q
___ shapes are doubly symmetric wide-flange shapes whose flanges are substantially parallel.
A
W
3
Q
_____ shapes are also wide-flange shapes whose flanges and webs are of the same nominal thickness and whose depth and width are essentially the same.
A
HP
4
Q
The ____ shapes are doubly symmetric shapes whose inside flange surfaces have approximately 16.67% slope.
A
S
5
Q
The ____ shapes are doubly symmetric shapes that cannot be classified as W, S, or HP shapes.
A
M
6
Q
_____ shapes are channels with inside flange surfaces having a slope of approximately 16.67%.
A
C
7
Q
_____ shapes are channels that cannot be classified as C shapes.
A
MC
8
Q
______ shapes are angle shapes with either equal or unequal legs.
A
L
9
Q
In addition to these shapes, other structural sections are available, such as, ______
A
tee, sheet piling, rail
10
Q
The letter indicates the _____, while the two numbers indicate the ______ and the ______.
A
shape, nominal depth, weight per linear unit length
11
Q
An _____ shape is designated with the letter L, followed by three numbers that indicate the leg dimensions and thickness in inches.
A
angle
12
Q
Dimensions of these structural shapes are controlled by ASTM _____.
A
A6/A6M
13
Q
____ shapes are commonly used as beams or girders.
A
W
14
Q
_____ can also be formed by welding different shapes to use in various structural applications.
A
composite sections
15
Q
______ sections are connected to each other and are used as retaining walls.
A
sheet piling
16
Q
Since concrete has negligible tensile strength, structural concrete members subjected to tensile and flexural stresses must be _____.
A
reinforced
17
Q
In _____, the stresses fluctuate with loads on the structure. This does not place any special requirements on the steel.
A
conventional reinforcing
18
Q
In _______, the steel is under continuous tension.
A
prestressed reinforcement
19
Q
Any stress relaxation will ______ the effectiveness of the reinforcement.
A
reduce
20
Q
Reinforcing steel (rebar) is manufactured in three forms: _______.
A
plain bars, deformed bars, plain and deformed wire fabrics
21
Q
_____ are round, without surface deformations.
A
plain bars
22
Q
_____ provide only limited bond with the concrete and therefore are not typically used in sections subjected to tension or bending.
A
plain bars
23
Q
_____ have protrusions (deformations) at the surface, thus, they ensure a good bond between the bar and the concrete.
A
deformed bars
24
Q
The ____ of the bar prevents slipping, allowing the concrete and steel to work as one unit.
A
deformed surface
25
_____ are flat sheets in which wires pass each other at right angles, and one set of elements is parallel to the fabric axis.
wire fabrics
26
_____ develop the anchorage in concrete at the welded intersections
plain wire fabrics
27
______ develop anchorage through deformations and at the welded intersections.
deformed wire fabrics
28
______ are used in concrete beams, slabs, columns, walls, footings, pavements, and other concrete structures, as well as in masonry construction.
deformed bars
29
_____ are used in some concrete slabs and pavements, mostly to resist temperature and shrinkage stresses.
welded wire fabrics
30
_____ can be more economical to place and this allow for closer spacing of bars than is practical with individual bars.
welded wire fabrics
31
Bars are made of four types of steel: _______.
A615 (billet), A616 (rail), A617 (axle), A706 (low-alloy)
32
_____ is the most widely used.
A615 billet
33
____ steel is often used when the rebar must be welded to structural steel.
A706 low-alloy
34
Reinforcing steel is produced in _____ grades.
four
35
To permit ready identification of the different bar types in the field, there are four marking symbols: ______
1. letter code for manufacturer
2. numerical code for bar size
3. letter code for type of steel
4. grade of steel designated by either grade lines or numerical coded
36
Grade 40 or 300
no designation
37
Grade 60 or 420
one grade line between the main ribs or the number 4
38
Grade 75 or 520
two grade lines between the main ribs or the number 5
39
_____ requires special wires, cables, and bars.
prestressed concrete
40
Steel for prestressed concrete reinforcement must have ____ strength and ____ relaxation properties.
high, low
41
Properties of prestressed concrete reinforcement are presented in ASTM specification _____ and AASHTO specification _____.
A416, M203
42
The specifications of prestressed concrete reinforcement allow two types of steel: _____.
stress-relieved (normal relaxation), low relaxation
43
______ refers to the percent of stress reduction that occurs when a constant amount of strain is applied over an extended time period.
relaxation
44
Both stress-relieved and low-relaxation steels can be specified as ____, with ultimate strengths of 1725 MPa (250 ksi) and 1860 MPa (270 ksi), respectively.
Grade 250 or Grade 270
45
Certain methods of fabrication, such as ________, may affect the properties of the material being tested.
bending, forming, welding, operations involving heating
46
The _____ on steel is performed to determine the yield strength, yield point, ultimate (tensile) strength, elongation, and reduction of area.
tension test (ASTM E8)
47
Typically, this test is performed at temperatures between 10 deg-C and 35 deg-C (50 deg-F to 95 deg-F)
tension test
48
It is desirable to use a _____ cross-sectional area at the center portion of the specimen to esnure fracture within the gauge length.
small
49
A ____ diameter round specimen is used in many cases.
12.5 mm (1/2 in.)
50
The gauge length over which the elongation is measured typically is ____ times the diameter for most round-rod specimens.
four
51
An _____ with a dial gauge or an LVDT is used to measure the deformation of the entire gauge length.
extensometer
52
As tension increases past the yield point, strain _____ following a nonlinear relation up to the point of failure.
increases
53
The true stress is slightly ______ than the engineering stress.
greater
54
The true strain is slightly _____ than the engineering strain.
less
55
As the strain level increases, especially as the neck is formed, the true stress becomes much _____ than the engineering stress, because of the reduced cross-sectional area at the neck.
larger
56
The necking also causes the true strain to be _____ than the engineering strain, since the increase in length at the vicinity of the neck is much larger than the increase in length outside of the neck.
larger
57
____ is generally assumed to be a homogeneous and isotropic material.
steel
58
_____ essentially causes the steel to undergo plastic deformations, with the degree of deformation varying throughout the member.
cold rolling
59
The _____ is used to determine the shear and modulus of structural materials.
torsion test (ASTM E143)
60
The _____ is used in the design of members subjected to torsion, such as rotating shafts and helical compression springs.
shear modulus
61
The ____ is the ratio of maximum shear stress to the corresponding shear strain below the proportional limit of the material, which is the slope of the straight line between R (a pretorque stress) and P (the proportional limit).
shear modulus
62
A ____ can be used to estimate the straight-line portion of the stress-strain relationship.
curve-fitting procedure
63
The ____ is used to measure the toughness of the material or the energy required to fracture a V-notched simply supported specimen.
Charpy V Notch impact test (ASTM E23)
64
The test is used for structural steels in tension members.
Charpy V notch impact test
65
The standard specimen is ______ (2.165 x 0.394 x 0.394 in.) with a V notch at the center of one side.
55 x 10 x 10 mm
66
The ____ of the specimen is typically measured after the test using a dial gauge device.
lateral expansion
67
The ____ is a measure of the plastic deformation during the test.
lateral expansion
68
The ____ the toughness of the steel, the larger the lateral expansion.
higher
69
The material changes from ductile to brittle as the temperature _____.
decreases
70
The ____ typically consists of a dull shear area (ductile) at the edges and a shiny cleavage are (brittle) at the center.
fracture surface
71
As the toughness of the steel decreases, due to lowering the temperature, for example, the shear area _______ while the cleavage area _____.
decreases, increases
72
The ductility to accommodate bending is checked by performing the semi guided _____.
bend test (ASTM E290)
73
The test evaluates the ability of steel, or a weld, to resist cracking during bending.
bend test
74
Three arrangements can be used in performing the bend test.
1. the specimen is fixed at one end
2. the specimen is held at one end and a rotating device is used to bend the specimen around the pin or mandrel
3. a force is applied in the middle of a specimen simply supported at both ends
75
______ is a measure of a material's resistance to localized plastic deformation, such as small dent or scratch on the surface of the material.
hardness
76
An ____ (penetrator) is forced into the surface of the material with a specified load magnitude and rate of application.
indenter
77
One of the methods commonly used to measure hardness of steel and other materials is _______?
Rockwell hardness test (ASTM E18)
78
To test very thin steel or thin surface layers, the _____ is used.
Rockwell superficial hardness test
79
______ is a nondestructive method for detecting flaws in materials.
ultrasonic testing
80
It is particularly useful for the evaluation of welds.
ultrasonic testing
81
This method is highly sensitive in detecting planar defects, such as incomplete weld fusion, delimitation, or cracks (Hassett, 2003).
ultrasonic testing
82
_____ is defined as the destruction of material by electrochemical reaction to the environment.
corrosion
83
______ can be defined as the destruction that can be detected by rust formation.
corrosion of steel
84
Corrosion is an ______ process; that is, it is a chemical reaction in which there is transfer of electrons from one chemical species to another.
electrochemical
85
In the case or steel, the transfer is between iron and steel a process called ____.
oxidation reduction
86
Corrosion requires the following four elements (without any of them corrosion will not occur): _____
an anode, a cathode, a conductor, an electrolyte
87
The electrode where corrosion occurs.
anode
88
The other electrode needed to form a corrosion cell.
cathode
89
A metallic pathway for electrons to flow.
conductor
90
A liquid that can support the flow of electrons.
electrolyte
91
_____ is also an electrical conductor. Therefore, it contains three or four elements needed for corrosion, while moisture is usually the fourth element (electrolyte).
steel
92
The basic reactions for atmospherically exposed steel in a chemically neutral environment are ________.
dissolution of the metal at the anode, reduction of oxygen at the cathode
93
_____, from deicing or a marine environment, is a common contaminant that accelerates corrosion of steel bridges and reinforcing steel in concrete.
salt
94
The _____ plays an important role in determining corrosion rates.
environment
95
There are three mechanisms by which coating provide corrosion protection (Hare, 1987): _____
barrier coatings, inhibitive primer coatings, sacrificial primers
96
_______ work solely by isolating the steel from the moisture. These coatings have low water and oxygen permeability.
barrier coatings
97
_______ contain passivating pigments. They are low-solubility pigments that migrate to the steel surface when moisture passes through the film to passive the steel surface.
inhibitive primer coatings
98
______ contain pigments such as elemental zinc. There should be close contact between the steel and the sacrificial primer in order to have an effective corrosion protection.
sacrificial primers (cathodic protection)
99
_____ can take forms other than coating. For example, steel structures such as water heaters, underground tanks and pipes, and marine equipment can be electrically connected to another metal that is more reactive in the particular environment, such as magnesium or zinc.
cathodic protection
100
Such reactive metal (_______) experiences oxidation and gives up electrons to the steel protecting the steel from corrosion.
sacrificial anode
