Arch 261 Building Materials PDF

Buildin g Envelop e Materia ls Arch 261_Building  Lecture 1. Metal envelope 2. Clay product outline envelope Arch 261_Building  Meta...

Buildin g Envelop e Materia ls Arch 261_Building  Lecture 1. Metal envelope 2. Clay product outline envelope Arch 261_Building  Metal Envelope Arch 261_Building Arch 261_Building Arch 261_Building  Main metals used in building envelope Building envelope ? Arch 261_Building  Main metals used in building envelope Aluminiu m Copper Zinc Lead Tin Nickel Titanium Arch 261_Building  Aluminiu m Bauxite is the sedimentary rock with high concentration of aluminium Bauxite is converted to aluminium by: roasting, grinding, heating and filtering. calcined at 1000 °C. It Thenis electrolysis agitated toprocess precipitate Electrolysis is the process of the occurs. hydrate which is separating the metal from other ore washed and impurities by application of DC to Arch 261_Building induce a reaction.  Aluminium properties Silver white colour Malleable Ductile material light , strong, durable Low thermal conductivity Good electricity conductor Tempered at 350 °C Melted at 657 °C. Arch Corrosion resistive 261_Building  Aluminium applications Arch 261_Building  Aluminium applications in Building Envelope Arch 261_Building  Aluminium applications in Building Envelope Arch 261_Building  Aluminium applications in Building Envelope Arch 261_Building  Aluminium applications in Building Envelope Arch 261_Building  Aluminium applications in Building Envelope Arch 261_Building  Aluminium applications in Building Envelope Arch 261_Building  Aluminium applications in Building Envelope Arch 261_Building  Aluminium applications in Building Envelope Arch 261_Building  Aluminium applications in Building Envelope Arch 261_Building  Aluminium applications in Building Envelope Arch 261_Building  Aluminium applications in Building Envelope Arch 261_Building  Aluminium applications in Building Envelope Arch 261_Building  Aluminium applications in Building Envelope Arch 261_Building  Aluminium applications in Building Envelope Arch 261_Building  Aluminium applications in Building Envelope Arch 261_Building  Aluminium applications in Building Envelope Arch 261_Building  Aluminium applications in Building Envelope Arch 261_Building  Aluminium applications in Building Envelope Arch 261_Building  Aluminium applications in Building Envelope Arch 261_Building  Aluminium applications in Building Envelope Arch 261_Building  Aluminium alloys Aluminium is alloyed with copper, manganese, zinc, silicon, nickel. Duralumin ○ Contains: 3-5% copper, 0.5-1% magnesium, 0-0.07% manganese, 0.3- 0.6% silica ○ It is highly resistant to corrosion ○ When rolled and heat treated gains high strength and it is a light material ○ It is fabricated to different structural shapes ○ Widely used in aircraft Arch 261_Building  Aluminium alloys Aluminium is alloyed with copper, manganese, zinc, silicon, nickel. Magnalium ○ Contains: 6% magnesium ○ Very good mechanical properties ○ Lighter compared with pure aluminium ○ Easy to work ○ Used in making engine parts of automobiles and wheel rim. Arch 261_Building  Aluminium alloys Aluminium is alloyed with copper, manganese, zinc, silicon, nickel. Aldural ○ It is duralumin coated with aluminium for enhancing corrosion resistance properties Arch 261_Building  Coppe r Extracted from ores of: Chalcopyrite (34.5% of copper), malachite (57.3% of copper), copper glance (79.8% of copper) The copper is extracted by smelting The crude copper known as blister contains many impurities and is Arch 261_Building  Copper properties Bright shining metal of reddish colour which turns greenish after oxidation (contact with air). Malleable and ductile and can be work in hot and cold conditions It is not weldable Soft and good conductor of heat and electricity High tensile strength Widely used for electrical properties Arch 261_Building  Copper applications Arch 261_Building  Copper applications Arch 261_Building  Copper applications in Building Envelope Arch 261_Building  Copper applications in Building Envelope Arch 261_Building  Copper applications in Building Envelope Arch 261_Building  Copper applications in Building Envelope Arch 261_Building  Copper alloys Brass ○ 60-90% of copper and 10-40% of zinc. ○ The colour is silvery white for low content of copper and red for high copper content ○ Brass can be either cast or wrought. ○ Cast brasses are stronger than copper and zinc. ○ Other elements used in brass derivatives are tin , aluminium, lead ○ With 80-85% of copper brass resembles very closely to gold. Arch 261_Building  Brass applications Arch 261_Building  Brass applications in Building Envelope Arch 261_Building  Brass applications in Building Envelope Arch 261_Building  Copper alloys Bronze ○ Alloy of copper, tin and one or more additional metal. ○ Colour darker than copper ○ Malleable but not as much as brass ○ 95% copper and 5% of tin is used for coin production. ○ Copper 65-45% , zinc 35-20% and nickel 5-35% used for bell making. Arch 261_Building  Bronze applications Arch 261_Building  Bronze applications in Building Envelope Arch 261_Building  Bronze applications in Building Envelope Arch 261_Building  Zin c The main source of zinc is sulphide ore zinc blende The sulphide ore is calcined in furnace until all the sulphur amount is expelled Ore containing impurities of iron is calcined to powder and iron is removed by electromagnet Also the electrolysis Arch 261_Building  Zinc properties Zinc is resistant to atmospheric corrosion Easy malleable It is used in the production of brass and some bronzes As protective coating against corrosion. Light grey colour Zinc tarnish by the continuously contact with water Zinc is used in production of paints, cosmetics, soaps, inks, plastics, etc. Arch 261_Building  Zinc applications Arch 261_Building  Zinc applications in Building Envelope Arch 261_Building  Zinc applications in Building Envelope Arch 261_Building  Zinc applications in Building Envelope Arch 261_Building  Lea din its pure form Mainly used It is the densest, softest and the weakest metal. The main ore where lead is extracted from is lead sulphide which contains 86.6% of lead. After removing the sulphur content the remaining is smelt in furnace and lead, zinc, copper and arsenic are removed based Arch 261_Building on  Lead properties Pure lead can be scratched by fingernails Highly malleable Can be rolled into thin foils It has a blue gray colour when freshly cut. Tarnishes into dull grey colour when exposed to air 327 °C melting point Is used in paints, automobile batteries etc. High corrosion resistance Toxic Arch 261_Building  Lead applications Arch 261_Building  Lead applications in Building Envelope Arch 261_Building  Lead applications in Building Envelope Arch 261_Building  Ti n black oxide Extracted from of tin which contains 78.6% of tin. Extracted from ore by crushing, roasting and melting. Arch 261_Building  Tin properties Silvery white lustrous Extremely malleable (can be cut by knife) Melts at 232 °C It is harder, ductile and stronger than lead Highly resistant to corrosion and low tensile strength. It is used to make cans. It is used for making bronze and other alloys. Arch 261_Building  Tin applications Arch 261_Building  Nickel and its properties Extracted from pyrites or silicate ores Silver in colour 1500 °C melting point Nickel is used in making nickel steels, coins Used to coat other metals Arch 261_Building  Titanium Is as strong as steel but less dense Is an alloying agent with many metals such as iron and aluminium Very resistance against corrosion, used also in contact with sea water Most extensively titanium is used in its oxide form for house paints, paper formation and plastics. 1,668 °C melting point Arch 261_Building  Titanium applications in Building Envelope Arch 261_Building  Noble metals Noble metals are considered those that resist corrosion and does not react with air ○ Gold, silver, platinum. Applied in architecture for decorative purposes. Arch 261_Building  Clay product Envelope Arch 261_Building  Main clay products used in building envelope Bricks Roof tiles Terracott a glazing Arch 261_Building  Roof tiles Manufactured in the same way as brick but require greater care because are thinner and lighter.. Arch 261_Building  Roof tile characteristics A good roofing tile should possesses the following characteristics: Uniform texture Accurate size and shape Water absorption less than 15% Durability Arch 261_Building  Roof tile typologies Plain tiling Pan tiling Spanish tiling Italian tiling Arch 261_Building  Plain tiling Arch 261_Building  Pan tiling Arch 261_Building  Spanish tiling Italian tiling Arch 261_Building  Terracott a Italia word (terra-clay n & cotta-burnt) The clay used for terracotta should have superior quality and should possess sufficient amount of iron and alkaline matters By varying iron oxide in clay, desired colour can be obtained. The clay is mixed with powdered glasses, pottery and sand Arch 261_Building  Terracotta characteristics A good roofing tile should possesses the following characteristics: Impervious, hard and cheap When properly made the material weathers well and because of its glazed surface can be cleaned easily. Burned between 1100 - 1200 °C. Dry clay 50–60%, Ground glass 8–10%, Crushed pottery 20%, Clean white sand 10–20%. Arch 261_Building  Terracotta typologies Porous terracotta Light weight. Resistant to weathering action. Fire resistant. Can be nailed and sawn to various shapes. Sound proof. Poor strength—used only for ornamental works. Arch 261_Building  Terracotta typologies Polished terracotta (due to high concentration of glass) is hard, strong and durable. can be given different colours. is leak proof (water absorption < 12 per cent) and can be easily cleaned. is fireproof. Arch 261_Building  Terracotta uses Polished terracotta (due to high concentration of glass) Hollow blocks of terracotta are used for masonry. Cornices and arches. Statuettes. Ornamental works. Being fire proof, terracotta is most suitable as casing for steel columns and beams. Porous terracotta is used for sound insulation. Arch 261_Building  Terracotta jewelry Arch 261_Building  Terracotta facade cladding Arch 261_Building  Terracotta facade cladding Arch 261_Building  Terracotta facade cladding Arch 261_Building  Glazin g Transparent glazing Opaque glazing Arch 261_Building  Transparent glazing Salt glazing method is most commonly applied Is the process of throwing sodium chloride in a kiln when burning is at its peak 1200 - 1300°C. The salt combines with silica in clay to make soda silicate, and soda silicate combines with alumina, lime, iron in the clay to form a permanent thin transparent layer. Arch 261_Building  Opaque glazing This is known as enamelling Borax, kaolin, chalk and colouring matter is fired with total or a part of felspar, flint, and lead oxide. The resulting molten glass is poured into water to give shattered frit. The frit is then ground with remaining materials and water to form a cream known as slip. Fully burnt earthenwares known as biscuits are dipped in the slip. The biscuits absorb water and form thin layer of glaze on the surfaces. After drying the products, these are once again fired to a lower temperature so as to fuse the glaze. Arch 261_Building Arch 261_Building