Metals

frizzflowerUrban and Civil

Nov 29, 2013 (3 years and 8 months ago)

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Metals

Introduction


Metal is used in various places in the
construction process including:


rebar

= reinforcing steel in round shapes


flashing

= thin metal


door & window frames

= in shapes of frames


connectors
= used to attach or connect members


fasteners

= to join construction parts


structural steel

= shapes of steel for various building
parts

Reinforcing Bar
-

Rebar


Embedded in concrete to strengthen


concrete
-

strong in compression, weak in tension


steel rebar
-

strong in both tension and compression


together strengthens overall material makeup


both concrete & steel have the coefficient of
expansion similar to each other, making materials
compatible to each other

Reinforcing Bar Sizes and Shapes


Rebars
(reinforcing bars)

are designated by
1/8” intervals


Sizes available in 1/8” diameter increments


range in size from #3(3/8”) to #18(2 1/4”)


#3 bar = 3/8”


#4 bar = 1/2” (most common in residential)


#5 bar = 5/8”


#6 bar = 3/4”


#7 bar = 7/8”


etc.

Rebar Representation


Heavy dot in section view


Heavy dashed line in elevation/plan view

Rebar Callout


Typical callout:

#4 BAR @ 24” OC


Material: made from billet steel
& old rail steel


Shape
--
Plain & Deformed bar

Dowels
-

Short lengths of Rebar


Used to unite 2 concrete elements


tie footing to foundation wall


tie concrete slab to foundation wall

Compression vs. Tension


Compressive force is one that
pushes

or
tends to shorten

Compressive Force

Compression vs. Tension


When a load is placed on a concrete
surface, both tensile and compressive forces
develop

Load

Compression vs. Tension


This can be better understood by looking at
an exaggerated deformation of the part

Load

Compression
-

elements

shortened, top portion

Tension
-

elements are


lengthened, bottom portion

Center axis

Note: rebar is placed
in area of tension

Loads on Concrete


Dead loads


Frost


Rebar in areas of tension

Flashing


Sheet metal that covers intersection of 2 or
more building members

Purpose of Flashing


Protects against water & dirt infiltration,
leakage & rot


Provides a protective covering for wood
members


Seals a joint of 2 intersection members

Flashing Material


Typically galvanized iron


Callout:

#26 GA. G.I. FLASHING



Gauge #


Thickness




11



1/8”



16



1/16”



22



1/32”



26



.01875”

Flashing


No. 26 (3/160” = .01875”) most common


24 Gauge used for commercial work


Heavy gauges require special tools for
bending

Foundation Flashing


Flashing to protect
sill plate

Metal Door Frames


More common in commercial than
residential construction


Increased durability


May be required by code


Same as wood counterparts,
except usually all one piece

Thresholds


Member below the bottom of door that is
secured to floor

Thresholds


Used to prevent water & air from entering
building


Commonly made from oak or aluminum


aluminum thresholds are extruded shapes


Tread patterns used to minimize slipping

Metal Threshold Sections


Metal Connectors


Used to join wood framing members
securely together


joist hangers


beam connectors

Beam Connectors

Good to prevent wind uplift

Nails


Used to fasten
members together


common vs. box


d = penny


8d
-

sheathing


16d
-

studs


“d” stands for
penny in the
English monetary
system, the price of
100 nails, 100 16d nails were 16 pence (pennies)

Nail Usage


Perpendicular
vs. Toe nailing

GOOD

BAD

Lag Bolts


Threaded


wood screw type


More sturdy than
nails


predrilled hole
necessary


Used in larger
members

Foundation Anchor Bolts


Used to
fasten sill
plate to
foundation


L
-
shaped &
threaded


Spacing set
by code


usually 4’
-
8’ OC

Machine Bolts


Material
--
steel


galvanized or bright plate finishes


Heads


hexagonal and square


Used for the fastening of wood members
when heavy metal connectors are involved.


Diameter Size Length

»
1/2” to 1 1/2” 3 1/2” to 30 “

Structural Steel


Shapes


Wide Flange (W)


Standard (S)


Miscellaneous (M)


Channels (C)


Angles (L)


Pipe, sq. & round


Tee (T)


Light Gauge Steel Framing


Steel Stud materials: Studs, runners(for
plates) and floor and ceiling joist







Roof and Floor Decking


Metal Siding and Roofing

Example of Light Steel Framing

Head Detail over a Door

Steel Decking


Corrugated steel decking
supported by steel channels
or open
-
web joist


Common shapes shown


Common depths:


1 1/2”, 2”, 3” & 4 1/2”


Minimum concrete coverage:

1 1/2”


Application
Detail:

Open
-
Web Steel Joist and Steel
Decking Example

Metal Grating


Several applications:
1
--
ventilation

(sometimes called a
grille or register)
within a building
2
--
a cover for a
drainage system

interior or exterior
of buildings

Metal Stair Handrail drawing


Additional Info:


1
--
Handrail is a

C

1 1/2x 2.4 channel, draw to
given size, attached with 1/16
fillet weld all around tube

2
--
Lower horizontal bar is a C 1
1/4x 1.3 (1 1/4” x 1/2” x 1/8”)
channel, attached with 1/16
fillet weld three sides draw 7”
above deck

3
--
Support channel is a C6x8.2

(12 GAGI)

4
--

Weld leader lines with dot(•)
is replaced by a darkened flag

Scale: 3” = 1’
-
0”

Support Channel

7


Assignment