Bcn1210 Test 4 Review - Steel – Ch 18

Front 1

Because of its extensive use in construction, ___ is by far the most important of all metals.

Back 1

Iron

Front 2

Metals are generally divided into two categories:

Back 2

Ferrous and non-ferrous metals

Front 3

Define ferrous and non-ferrous metals.

Back 3

Ferrous: metals that contain iron (latin word for iron=ferrum)
Non-ferrous: metals that do not contain iron (aluminum, copper, specialty metals like brass)

Front 4

___ is the most important ferrous metal.

Back 4

Steel

Front 5

Steel’s ___ in relation to its ___ makes it the material of choice for skyscrapers and long-span structures, such as sports stadiums and bridges.

Back 5

High strength to its weight

Front 6

Steel’s ___ and ___ allow it to be shaped, bent, and made into different types of components.

Back 6

Malleability and weldability

Front 7

These characteristics, ___ and ___, provide the versatility that architects and engineers have exploited in creating a wide range of highly expressive structures.

Back 7

1. High strength to weight ratio
2. Malleability and weldability

Front 8

___ is the earliest form of iron.

Back 8

Wrought iron

Front 9

___ led to the discovery of the blast furnace

Back 9

Cast iron

Front 10

Wrought iron has ___ carbon and cast iron has ___ carbon.

Back 10

Wrought iron: nearly .02%
Cast iron: 2.5 – 4%

Front 11

The perfect amount of carbon in iron is ___ which produces ___.

Back 11

0.1 – 1.7%, steel

Front 12

___ is the process where ___, ___, and ___ are reheated to virtual softening and rolled to the required cross sections.

Back 12

Hot rolling; billets, blooms, and slabs

Front 13

Name the three major components of an integrated mill?

Back 13

1. Blast furnace
2. Basic oxygen furnace (BOF)
3. Rolling mill

Front 14

In a mini mill, a(n) ___ converts scrap steel into molten steel

Back 14

Electric arc furnace (EAF)

Front 15

Some mini mills produce near-net shape bills, also called ___, which are subsequently rolled into I-sections.

Back 15

Beam blanks

Front 16

Rectangular billets can be used for rolling into ___, ___, ___ and ___.

Back 16

Channels, angles, bars and rods

Front 17

The mini mill method relies on ___.

Back 17

Scrap recycling

Front 18

After shredding, scrap is separated into ___ and ___ scrap using magnetic separation.

Back 18

Ferrous and non-ferrous

Front 19

Non-ferrous scrap is further separated into ___ and ___.

Back 19

Metals (copper, aluminum)
Nonmetals (plastics, rubber, fabric)

Front 20

After shredding goes through shredding and separation, it is stored in the yard as feed for the ___.

Back 20

EAF (Electric Arc Furnace)

Front 21

___ is a waste product from the blast furnace and the electric arc furnace.

Back 21

Slag

Front 22

___ is noncombustible and is similar to fiberglass in its thermal properties.

Back 22

Slagwool

Front 23

Because of their appearance, steel buildings have been coined:

Back 23

Skeleton cage, steel skeleton, and skeleton frame

Front 24

For design and construction professionals, 3 steel classification systems are important:

Back 24

Classification based on steel’s application, strength, and metallurgy

Front 25

In an application-based classification, steel may be classified as:

Back 25

Structural steel, cold-formed steel, reinforcing steel, pre-stressing (post-tensioning) steel

Front 26

____ members include steel cross-sections, such as I-sections, H-sections, T-sections, C-sections (channels), L-sections (angles), plates, pipes, and rectangular tubes (hollow sections).

Back 26

Structural steel members

Front 27

____ members are made from thin sheets of steel by bending sheets to various corrugated profiles at room temperatures, hence the term ___.

Back 27

Cold-formed (or light-gauge) steel members; cold-formed

Front 28

___ is in the form of deformed round bars (also called rebars) that are used in concrete slabs, beams, and columns.

Back 28

Reinforcing steel

Front 29

___ is used in precast concrete or post-tensioned concrete members as a replacement for (or in conjunction with) reinforcing steal.

Back 29

Pre-stressing steel

Front 30

Steel is ___ during manufacturing with a small percentage of other metals to obtain steels that vary from each other with respect to a few important properties, such as ___, ___, and ___.

Back 30

Alloyed; yield strength, tensile strength, and corrosion resistance

Front 31

The yield strength of steel is also referred to as the ___. Thus, a steel with a yield strength of 50 ksi is called ___.

Back 31

Steel’s grade; grade 50 steel

Front 32

A simple metallurgic distinction between the steels used in building construction is ___ and ___.

Back 32

Carbon steel and alloy steel

Front 33

Increasing the amount of carbon ___ steel’s strength but ___ its ductility and formality, and vice versa.

Back 33

Increases; reduces

Front 34

Sheet steel is made from ___

Back 34

Low-carbon steel

Front 35

___ contains other metals to change steel’s properties.

Back 35

Alloy

Front 36

___ and ___ are alloy steels.

Back 36

Weathering steel and stainless steel

Front 37

___ is the primary alloying metal in stainless steel.

Back 37

Chromium

Front 38

Hot-rolled steel is available in cross-sectional shapes of:

Back 38

I, C, L, and T, pipes, tubes, round and rectangular bars, and plates

Front 39

Structural steel I-sections may be classified into four shapes:

Back 39

W, S, HP, and M-shapes

Front 40

T/F. Miscellaneous shapes and channels have a standard slope on inner flange surfaces.

Back 40

False. Misc shapes/channels DO NOT have standard slopes on inner flange.

Front 41

A T-shape section is made by splitting a ___, ___, or ___ into two equal parts. There they are called ___, ___, or ___ depending on their origin. For example, ___ is/are obtained from one W12x58.

Back 41

W, M, or S-shape; WT, MT, ST; two WT6x29 sections

Front 42

T/F. Steel angles (L-shapes) may be either equal-leg angles or unequal-leg angles.

Back 42

True

Front 43

Angles are designated by three numbers. Describe them.

Back 43

First/second: length of each leg (first = longer leg)
Third: thickness of the legs (which are the same for both)

Front 44

Pipes are designated by their ___ and by whether the pipe is a ___, ___, or ___.

Back 44

Nominal diameter;
Standard weight, extra strong, or double-extra strong (refers to pipe’s wall thickness (depth)

Front 45

Angles have various uses, such as ___ and ___.

Back 45

Masonry lintels and members of steel trusses

Front 46

Pipes are generally used as ___ or ___.

Back 46

Columns or members of a truss

Front 47

A tube is referred to as a ___ and is made by bending a steel plate and welding it seamlessly, which is why the edges of a tube are rounded.

Back 47

Hollow structural section (HSS)

Front 48

An HSS may be ___, ___, or ___.

Back 48

Square (columns), rectangular (beams), or round (columns),

Front 49

T/F. Like pipe trusses, HSS member trusses are fairly common for long-san structures

Back 49

True

Front 50

Plate steel is designated by its ___

Back 50

Thickness

Front 51

Plate steel can be used for:

Back 51

Bearing plates, web stiffeners, site fabricated girders/beams/columns (not as common)

Front 52

In addition to standard steel shapes and built-up sections, two types of prefabricated steel members are commonly used for roof and floor structures in buildings:

Back 52

Joists and joist girders

Front 53

There is no fundamental difference between a joist and a joist girder, except that:

Back 53

A joist girder is a heavier member and spans from column to column, whereas a joist is a light member that spans between girders.

Front 54

The Steel Joist Institute classifies joists into three categories:

Back 54

K-series joists (depth 8”-30”)
LH-series joists (depth 18”-48”)
DLH-series joists (depth 52”-72”)

Front 55

Standard depth of end-bearing K-series joist:

Back 55

2 ½ in. (height/depth of end-bearing for all K-series

Front 56

Describe the K-series joist designation for 16K4.

Back 56

16 is depth of joist (can range 8-30” in 2” increments)
4 is relative weight (range 1-12” in steps of 1)

Front 57

What is the typical spacing of K-series joists?

Back 57

Determined by engineer or architect, but generally varies 2-4’ for floors, and 4-6’ for roofs

Front 58

What is the maximum allowable span of a joist?

Back 58

24 times the depth

Front 59

Steel joists and girders are slender elements and therefore ___ and prone to ___.

Back 59

Unstable; overturning

Front 60

As per SJI’s specs, steel joists must be stabilized by rows of continuous horizontal members referred to as:

Back 60

Horizontal bridging members

Front 61

___ of steel joists is an alternative to horizontal bridging.

Back 61

Diagonal bridging

Front 62

Regardless of the bridging system used, the bridging members must be securely connected to the ___ or ___.

Back 62

exterior wall or spandrel beam

Front 63

Steel decks are made from sheet steel by pressing the sheets into various cross-sectional profiled at room temperature, hence the term ___ which are available in two categories:

Back 63

Cold-formed steel; roof decks and floor decks

Front 64

What is the primary difference between a roof deck and floor deck?

Back 64

Roof deck is generally topped with rigid insulation and a roofing membrane (for waterproofing), and a floor deck is topped with structural fill

Front 65

What is are the parts of a deck?

Back 65

Rib (flute) opening, top flange (pan), deck depth, rib (flute) width, web

Front 66

Name the different deck types.

Back 66

NR – narrow rib deck
IR – intermediate rib deck
WR – wide rib deck
DR – deep rib deck
LS – long span deck
Cellular deck

Front 67

Regarding deck spanning, if gauge value decreases, the span ___.

Back 67

Increases

Front 68

Two types of floor decks used are:

Back 68

1. form deck: functions as permanent formwork only which must be reinforced
2. composite deck: also functions as steel reinforcement for concrete slab (acts as the reinforcement)

Front 69

Both composite deck and form deck can be made to act compositely with the supporting beams by using ___ which prevent slippage of the deck under bending of the underlying beam.

Back 69

Shear studs

Front 70

T/F. Because steel (unlike aluminum) does not automatically form a protective oxide coating, it must be protected from corrosion.

Back 70

True. However structural steel members enclosed by the building envelope do not require any protective coating unless in a corrosive environment.

Front 71

Several protective coatings are available for steel to suit different environmental conditions, aesthetic requirements and budget which include:

Back 71

Acrylics, epoxies, polyurethanes, and zinc coatings. *polyurethane coatings are the hardest, toughest, and most versatile

Front 72

For cold-formed and light structural steel members, ___ is a cost-effective solution.

Back 72

Zinc-coating aka galvanizing

Front 73

Two ways to protect steel against fire are:

Back 73

1. insulate with noncombustible thermal insulation
2. encase with noncombustible thermal material with high capacity, such as concrete (poured), gypsum board (wrapped), or water.

Front 74

An alternative to gypsum board encasement is ___ on steel members.

Back 74

Intumescent paint (typically 20-50 mil swells to 2-4” thick = char layer