METALS

• a soft, nonmagnetic silvery metal

• characterized by its light weight

• low melting point

• high thermal and electrical conductivity

ALUMINUM

• rod

• bar

• extrusion

• casting

• sheet

• strip

all fabricated forms of aluminum

process of shaping material by forcing it to flow through a shaped opening in a die

EXTRUSION

• term applied to certain aluminum products

• refers to the protective coating (cladding) applied

• primarily for corrosion resistance

Alclad

improves the appearance of the alloy

Cladding

a. Types of Aluminum:

This is rigidized sheet fabricated of special aluminum alloys specifically developed for this purpose.

CORRUGATED ALUMINUM

a. Types of Aluminum:

• When aluminum is used as a structural material, important factors, arising from its physical and chemical characteristics, are considered:

- Aluminum can be extruded

- Very corrosion resistant aluminum alloys are available

STRUCTURAL ALUMINUM

a. Types of Aluminum:

These are generally fabricated from extrusions and rolled shapes.

ALUMINUM DOORS AND WINDOWS.

a. Types of Aluminum:

• are pre-fabricated units, generally manufactured:

- using dimensions of modular and non-modular window-width for building exterior

ALUMINUM PANELS AND SANDWICH PANELS

A sandwich panel comprises a system of construction called _________

skin construction

a. Types of Aluminum:

Many kinds of rods, bars, pipes, railings, fittings, and special shapes are manufactured as stock items for use in ornamental design of railings, grilles, screens, etc.

Ornamental aluminum

a. Types of Aluminum:

are used for fencing, particularly chain link fencing and insect screening.

Aluminum Mesh and Wire Cloth

b. Types of Aluminum Finishes:

obtained by grinding polishing, scratching, sandblasting, embossing, or other treatment of the surface to achieve a desired effect or to provide a base for other finishes.

Mechanical finishes

b. Types of Aluminum Finishes:

• based on chemical reactions with the aluminum surface to achieve one of the following results:

(a) etching, cleaning, or polishing of the surface to remove any oxide film or surface irregularity and provide a design, a clean surface texture, or a polished effect

(b) oxidizing the surface with aluminum or other metallic oxides that protect the surface or serve as a base for subsequent treatment, or both.

Chemical finishes

b. Types of Aluminum Finishes:

• Commonly referred to as anodized finishes, these finishes are based on the specific ability of aluminum to develop a protective coating of oxide on its surface.

• The coating formed may be transparent or opaque

• Of the colors used in anodic treatments, architectural gold has proven to be one of the most stable from the standpoint of fade resistance.

Electrolytic finishes

b. Types of Aluminum Finishes:

Aluminum can be covered with a protective or decorative film or another metal, usually by electrodeposition.

Electroplating

b. Types of Aluminum Finishes:

This finish forms a hard, resistant surface.

Porcelain or Vitreous Enamel

b. Types of Aluminum Finishes:

• Paint, lacquer and enamel can be applied as finishes to aluminum surfaces that have been prepared by a suitable chemical treatment finish.

• Lead base paints must not be used on aluminum.

Paint

• tough

• malleable silvery-white

• soft and ductile as copper

• easily magnetized

• can be hardened by heating and sudden cooling

IRON

The commercial form in which iron is first prepared

crude or pig iron

• is an iron-carbon alloy that contains more than 1.7% carbon

• is poured while molten into forms

• can be easily cast into any shape, but it is too hard and brittle to be shaped by hammering, rolling, or pressing

Cast Iron

• is almost pure iron with less than 0.1% carbon, usually not more than 0.05%

• contains 2.5%, of slag (iron silicate) in purely physical association, not alloyed

• is soft, malleable, tough, fatigue resistant, and resistant to progressive corrosion

• has good machinability and can be forged, bent, rolled, drawn, and spun. It can be welded by any of the commonly used procedures

Wrought Iron

• The word “_____” refers usually to plain carbon steels which is defined as alloys of iron and carbon which do not contain more than 2% carbon and which are made in malleable or ingot form.

• In the plain or straight carbon steels the iron is always in excess of 95%

STEEL

a. Wrought Carbon Steels:

This is a medium carbon steel with its carbon content controlled to give both the strength and ductility necessary for its use.

Structural steel

a. Wrought Carbon Steels:

Usually deformed bars of varying grades and diameters.

Reinforcement of concrete

a. Wrought Carbon Steels:

Steel sheet is made from low carbon steels generally containing about 0.15% carbon and not exceeding 0.25% carbon.

Sheet and strip

a. Wrought Carbon Steels:

This is rigidized sheet fabricated from low-carbon cold or hot-rolled steel sheets which are either galvanized or covered with some type of bituminous coating.

Corrugated steel.

a. Wrought Carbon Steels:

They are used for concrete reinforcement, lath for plaster, stucco, and cement, fencing, insect screens.

Steel Mesh and Wire Cloth

a. Wrought Carbon Steels:

such as nails, screws, rivets, etc

Hardware

steels to which manganese, silicon, aluminum, titanium, and molybdenum have been added in sufficient quantity to produce properties unobtainable in carbon steels in cast, rolled or heat-treated form.

Alloy Steels

b. Alloy Steels:

are a group of trade name steels with improved mechanical properties and resistance to atmospheric corrosion

High-strength low-alloy steels

b. Alloy Steels:

• generally used in architecture are highly alloyed steels that contain more than 10% chromium

• They are characterized by their resistance to heat, oxidation and corrosion.

Stainless steels

• is ductile, malleable, nonmagnetic metal with a characteristic bright, reddish brown color

• has the highest electrical and thermal conductivity of any substances except silver

• highly resistant to corrosion by air and salt water.

COPPER

green color on copper, on exposure it soon reacts to form a surface layer of an insoluble green salt which retards further corrosion

patina

• is a soft, ductile, malleable, bluish-white metal.

• Because it is normally covered with a thin film of stannic oxide, it resists corrosion by air, moisture, sulfur dioxide, hydrogen sulfide

• takes a highly reflective polish and has the ability to wet other metals

TIN

• is medium hard, bluish-white metal

• characterized by brittleness and low strength.

• readily attacked by acids and alkalis.

• It is resistant to corrosion by water

ZINC

is the process whereby a protective coat of zinc is applied to steel and iron to protect them against corrosion.

Galvanizing

The most common galvanized material used in architecture

galvanized iron (steel) sheet and strip

• fundamentally an alloy of copper and zinc with small quantities of other elements sometimes added to give the special qualities.

• are less hard and strong than steels (iron-base alloys) but are superior in workability and resistance to corrosion

• react with other metals.

BRASS

• is an alloy of copper and tin which varies only slightly from 90% copper and 10% tin composition.

• a rich golden-brown metal, originally worked by forging and particularly suited for casting since it is corrosion resistant,

BRONZE

• Of the three types of socalled bronzes in architectural work, only one is true bronze.

• consist usually of 97% copper, 2% tin and 1% zinc.

statuary bronze

is really a leaded brass

architectural bronze

is one of the more commonly used brasses

commercial bronze

• a steel-white metal which takes a brilliant polish and is harder than cobalt or nickel.

• it is nonmagnetic at ordinary temperatures but becomes magnetic at 13F

• does not tarnish in air

CHROMIUM

• one of the most commonly encountered usage of this material in architecture.

• It gives a thin, hard, bright, wear resistant surface which sheds water when highly polished.

Chromium plating

• an inert silvery metal

• resistant to strong alkalis and to most acids

• It resembles iron in strength and toughness and copper in its resistance to oxidation and corrosion.

NICKEL

• is a blue-gray, soft, very heavy metal (the heaviest of the common metals)

• extremely workable

• has good corrosion resistance

LEAD

• method to join metals

• to make electrical connections

• to seal joints hermetically with another lower melting metal or alloy called the solder

SOLDERING

are mostly alloys of tin and lead in various proportions with small percentages of other elements added to give special characteristics

They can be divided into the following major types:

• tin-lead

• tin-lead-antimony

• silver-lead

Solders

defined as a metal joining process where the workpieces to be joined are immersed in a pot of molten solder

Metal Bath Dip

• In this method the iron piece is preheated and applied to the joint along with the solder and the flux

• the heat from the iron forms the soldered joint.

Soldering Iron

The parts to be soldered are heated by the torch flame and then the solder and flux are applied

This method is limited to metals which can be heated without altering their characteristics.

Torch

• The heating of the metals to be joined causes the solder to run into the joint

• This is the method used for joining copper tubing and fittings.

Sweat Method

• corrosive

• neutral

• noncorrosive

Three types of fluxes for soldering

• known as acid type and salt type fluxes

• Care should always be taken

Corrosive fluxes

mild in type and are used for easily soldered metals such as copper, brass, lead, and tin plate.

Neutral fluxes

a typical neutral flux

Stearic acid

• leaves residues which are noncorrosive and nonconductive and therefore need not be removed.

• Rosin is the principal flux of this type.

• are weak their fluxing action and their use are limited to the easily soldered base metals.

Noncorrosive fluxes

• a type of soldering in which the operating temperatures are higher (but lower than in welding)

• generally used where the shape and position of the joint or the composition of the metal or metals are not adaptable to welding

BRAZING

• is the process by which two metals are so joined that there is an actual union of the interatomic bonds.

• This may be brought about by close contact, heating, pressure, adding molten metal, or combinations of these methods.

• The resulting joints are as strong or stronger than the metals joined.

WELDING

• pressure welding

• fusion welding

Two general types of Welding

in which pressure and heat make the weld

pressure welding

• in which the heat and added metal make the weld

• the methods of heating are gas flame and electric arc

fusion welding

• devices used to join or fasten the metals

• a metal cylinder or rod which has a head at one end is inserted through holes in the materials being joined

RIVETS

• Reinforcement for concrete construction is mostly in the form of _______ and rods of round or square cross section

• The bars may be plain or deformed (with lugs or projections for better bonding to the concrete)

• They are called billet-steel bars or rail-steel bars.

STEEL BARS

• are made by the open hearth furnace by the acid Bessemer furnace and meet fixed chemical compositions.

• are rolled from billets directly reduced from ingots and come in three grades: structural, intermediate, and hard.

• For architectural purposes the intermediate grade is the most generally used.

Billet-steel bars

are rolled from standard T-rails and come only in one grade

Rail-steel bars

made of cold-drawn steel wire is widely used for the reinforcement of concrete slabs and floors, as well as for stuccoed work.

WIRE FABRIC

• Welded-wire mesh, also called _________, used to reinforce concrete slabs used in light construction., consists of a series wires welded together to form a grid pattern.

• It comes in various sizes & spacings and gauges, e.g. 4” x 4” – 6/6, 6” x 6” –8/8, etc.

• available in rolls 5 or 6 ft. wide, 150, 200, and 300 ft. long.

Welded Wire Fabric

• is built up of either single or stranded longitudinal wires with cross wires or bond-wires running diagonally across the fabric

• The longitudinal wires are spaced at 4” on centers and the cross wires 4” or 8” apart.

Triangle-mesh Wire Fabric

• This is manufactured from solid steel sheets

• free from mechanical and welded joints., e.g. STEELCRETE.

EXPANDED MESH

are furnished either in flat or segmental sheets, pressed into a series of solid ribs, between which the metal is stamped, perforated or deformed into an open mesh-work.

LATHS

• Metal reinforcement shall be stored in racks above the ground and away from moisture and vegetation.

• If a large quantity of reinforcement is stored at the site for an extended period, it is well to build shed over the storage racks.

• A bright-red rust, such as forms in a few days on reinforcement exposed to rain, is not in any way detrimental.

• Deep scaling should be considered a sufficient reason for condemning the use of reinforce unless it is first cleaned of mill and rust scale and used as the equivalent of a smaller size.

• All reinforcement should be kept free from oil which will tend to reduce the bond between concrete and steel.

STORAGE & CARE FOR METAL REINFORCEMENT