Soft, non-magnetic silvery white metal used in forming many hard, light alloys
High thermal and electrical conductivity
Light in weight (1/3 of iron, brass or copper)
Low Melting point – 1200⁰ F
Tensile strength 22,000 psi
Deficient in strength and soft – must be alloyed
High degree of corrosion resistance due to transparent film of oxide on its surface
Advantages: appearance & protection
Can be riveted, bolted, welded, brazed, and soldered.
Insulate from contact with other metals to prevent galvanic action (occurs between 2 dissimilar metals when enough moisture is present for electric current to flow. Will corrode one metal while plating the other)
Isolate from alkaline materials – wet concrete, mortar and plaster.
Used in extruded and sheet forms for secondary building elements – windows, doors, roofing, flashing, trim and hardware.
Structural framing – high strength aluminum alloys
Readily attacked by alkalis and hydrochloric acid and slowly attacked by dilute acids.
Easily worked and can be hot or cold rolled, extruded, forged, pressed, drawn, molded, stamped, bent and shaped.
Extrusion – process of shaping material by forcing it to flow through a shaped opening in a die.
Following pretreatment, controlled oxidixing process that produces a thicker, denser, harder oxide coating that adds durability
Exterior architectural application
Term applied to certain aluminum products and refers to the protective covering (cladding) applied, primarily for corrosion resistance, to thin sheets of alloy whose corrosion resistance has been decreased by the constituents added to give strength and other desirable characteristics.
TYPES OF ALUMINUM
ALUMINUM SHEET AND STRIP, used for roofing, flashing, gutter, etc.
ALUMINUM FOIL which is rolled to a thickness of 0.005” and is used mainly for thermal insulation and vapor barriers.
CORRUGATED ALUMINUM –rigidized sheet fabricated of special aluminum alloys specifically developed for roofing and siding purposes
Thickness can be reduced
Lightweight – increased efficiency w/ large bay spacing
ALUMINUM DOORS AND WINDOWS
Are pre-fabricated units which are generally manufactured on modular and non-modular window-width dimensions for the exterior of buildings and generally in 2’, 3’, and 4’ widths for interior partitions and dividers.
Consists of vapor barriers, condensation drains and lead-offs, insulation and an interior finish
SANDWICH PANEL – comprises a construction called skin construction. A cellular core of aluminum or other material has a skin of aluminum applied and bonded to both sides, thereby forming a unified whole in which all the components work as one.
Has good machinability, can be forged,bent,rolled, drawn and spun
Ductile, malleable metallic element widely used for electrical wiring, water piping.
Color and resistance to corrosion – excellent roofing and flashing.
Will corrode aluminum, steel, stainless steel, zinc.
Tensile strength – 36,000 to 70,000 psi
Rods, bars, tubes, sheets.
Any of various alloys consisting essentially of copper and zinc, used for windows, railings, trim and finish hardware
Heavy, soft, malleable, bluish gray metallic element used for flashing, sound isolation and radiation shielding. Although lead is the heaviest metal, its pliability makes it desirable for application over uneven surfaces. Lead dust and vapors are toxic
Iron-based alloy having a carbon content less than that of cast iron and more than that of wrought iron and having qualities of strength, hardness and elasticity.
Used for light and heavy structural framing, windows, doors, hardware and fastenings
Unalloyed steel in which the residual elements such as carbon, manganese, phosphorous, sulfur and silicon are controlled. Any increase in carbon content increases the strength and hardness of the steel but reduces its ductility and weldability
KINDS OF CARBON STEEL
MILD OR SOFT STEEL – low-carbon steel containing from 0.15% to 0.25% carbon.
MEDIUM STEEL – contains 0.25% to 0.45% carbon. Most structural steel is medium-carbon steel. ASTM A36 is the most common strength grade with a yield point of 36,000 psi.
HARD STEEL – high-carbon steel 0.45% -0.85% carbon
SPRING STEEL – high-carbon steel 0.85%-1.8% carbon
Carbon steel to which various elements such as chromium, cobalt, copper, manganese, molybdenum, nickel, tungsten, or vanadium have been added in a sufficient amount to obtain particular physical or chemical properties.
KINDS OF ALLOY STEEL
STAINLESS STEEL – contains a minimum of 12% chromium, sometimes with nickel, manganese, or molybdenum so as to be highly resistant to corrosion
HIGH-STRENGTH LOW-ALLOY STEEL – low-carbon steel containing less than 2% alloys in a chemical composition specifically developed for increase strength, ductility and resistance to corrosion. ASTM A572 is the most common strength with a yield point of 50,000 psi.
WEATHERING STEEL – high-strength, low-alloy steel that forms an oxide coating when exposed to rain or moisture in the atmosphere. This coating adheres firmly to the base metal and protects it from further corrosion. This should be detailed to prevent the small amount of oxide carried off by rainwater from staining adjoining materials.
TUNGSTEN STEEL - alloy steel containing 10% to 20% tungsten for increased hardness and heat retention at high temperatures.
CAST IRON – hard, brittle, non malleable iron-based alloy containing 2% to 4.5% carbon and 0.5% to 3% silicon cast in a sand mold and machined to make many building products such as piping, grating and ornamental work.
MALLEABLE CAST IRON – annealed by transforming the carbon content into graphite or removing it completely.
WROUGHT IRON – tough, malleable, relatively soft iron that is readily forged and welded,0.2% carbon and a small amount of slag
GALVANIZED IRON – coated with zinc to prevent rust
Occurs between two dissimilar metals when enough moisture is present for electric current to flow. This electric current will tend to corrode one metal while plating the other
Steel sections hot-rolled with ribs or other deformations for better mechanical bonding to concrete.
WELDED WIRE FABRIC
Consists of a grid of steel wires or bars welded together at all points of intersection. Typically used to provide temperature reinforcement for slabs but the heavier gauges can also be used to reinforce concrete walls. Size of grid in inches followed by wire gauge