Week 06 Logbook Anita Nicholls 698556
STUDIO MINDMAP
STUDIO MINDMAP
LEARNING LOOP ROOF SYSTEMS -‐Major horizontal enclosing elements Flat Roofs: Pitch 1 degree-‐3 degrees -‐concrete slab (waterproofed with a membrane) -‐support system might be a truss -‐Steel beams and a composite roof -‐Lighter weight Nmber joists Pitched and sloping roofs: >3 degrees -‐Timber or steel racers -‐Beams or purlins -‐Truss Tiles need to be at a greater slope (15 degrees or higher) compared to sheet metal roofing Concrete roofs: are generally flat plates of reinforced concrete, the top surface is sloped towards drainage points and the enNre roof surface finished with applied waterproof membrane) (ENVS10003, w6_m1) Structural steel framed roofs: -‐Flat (consist of a combinaNon of primary and secondary roof beams for heavier roof finishes. Or Roof Beams and Purlins for lighter sheet metal roofing) -‐Sloping (consist of roof beams and purlins and lighter sheet metal roofing) -‐Portal frames (consist of braced rigid frames (two columns and a beam) with purlins for the roof and grits for the two walls which are usually finished with sheet metal) Trussed roofs: are framed roofs constructed from a series of open web type steel or Nmber elements, manufactured from steel or Nmber components Space frames: (three dimensional trusses) are 3D plate type structures that are long spanning in two direcNons Members: circular hollow secNons or pipes. Linear steel secNons of various cross secNon types are welded, bolted or threaded together to form matrix-‐like structures Light framed roofs: GABBLE ROOFS are characterised by a verNcal, triangular secNon of wall at one or both ends of the roof -‐The roof consists of common racers, ridge beams and ceiling joists. Where the roof overhands the gable end wall outriggers are used -‐Materials (Nmber, cold-‐formed steel (and also someNmes heavier steel (UB or PFC) for major beams.) HIP ROOFS are characterised by a verNcal, triangular secNon of wall at one or both ands of the roof -‐The roof consists of Common racers, hip racers, valley racers, jack racers, ridge beams and ceiling joists. Material: Nmber, cold formed steel secNons.
INTRODUCTION TO METALS Metals are malleable and ducNle and not briTle. Types: Ferrous (iron) Non Ferrous: All other metals. Less likely to react with oxygen and have superior working qualiNes Alloys: A mixture of 2 or more metals (ferrous alloy if it contains iron, non ferrous if it does not) Proper>es: Varied hardness, plasNc when heated, ducNle. Low fragility, impermeable to light and water, high density (although varied), very good conducNvity (of heat and electricity) (can be advantageous or disadvantageous), not a good insulator, can be very durable if detailed well, high reusability, very high embodied energy although recyclable and renewable if correctly managed, cost effecNve. Metals react with other metals by giving up/taking on another metals ions. Anodic (more prone to corrosion)àcathodic (less prone to corrosion) end -‐Different metals in contact with each other are likely to corrode. ConsideraNon: Water related damage What is a truss? (6.08) • Trusses are efficient beams and can span long distances • High strength to material raNo • Need to be braced for stability Plates and Grids (2.18) Plate structures are rigid, planar (usually monolithic) structures that disperse applied loads in a mulNdirecNonal paTern. E.g. .a concrete slab The principal points and lines of support for a structural system typically define a grid. (2.21)
FERROUS METALS–iron metals and alloys -‐magneNc, quite reacNve chemically, good compressive strength History: Wrought ironàCast IronàSteel Wrought iron is formed when Iron is heated and hammered into the desired shape. (labour intensive and expensive) -‐used from circa 1000BC Cast iron is formed when iron is melted and the molten (liquid) metal is poured into moulds to cool. Generally only used for compression elements (e.g. columns) Steel is an alloy of Iron with Carbon as the primary addiNonal alloy element, different proporNons and combinaNons result in different types of steel ProperNes: very strong, transfers heat and electricity, can be formed into many different shapes (wires to reinforcing rods), long lasNng and resistant to wear Structural steel used for framing -‐Hot Rolled (used for primary structures, shaped while the metal Is hot) -‐Cold formed steel (folded from sheet steel, used as secondary structural elements e.g. purlins. -‐Reinforcing bars-‐ used in concrete because steel has good tensile strength, deformed in shape to grip onto concrete more effecNvely Common uses of steel: cladding and fooNng (must be protected from weather exposure) Stainless steel alloys: high quality, chromium is added to the steel, quite resistant to corrosion, commonly used in sheets, plates, wire, sheeNng in harsh environments, also used in commercial kitchens NON-‐FERROUS METALS AND ALLOYS Aluminium: very light compared to other metals, non magneNc , common in window framing, quite expensive in terms of cost and embodied energy, ]] Uses: extruded secNons are common for window frames, cast and used as door handles, rolled aluminium can be used as a cladding panel, reacts with the oxygen in air that keeps it from further oxidizaNon, other finish treatments can also be applied e.g. power coaNng Copper: Conducts electricity, ancient material found in its pure form in nature, very malleable and ducNle Uses: tradiNonally used as roofing material, natural weathering causes copper to develop a green paNna over Nme, it is also used in hot and cold domesNc water and heaNng pipework, and for electrical cabling. Zinc: In its pure form it is used as a reasonable expensive cladding system for walling and roofing -‐More commonly, a thin layer applied to steel (galvanising) DisNncNve properNes: Bluish-‐white, briTle at ambient temperatures but is malleable at 100-‐150 degrees. It is a reasonable conductor of electricity Lead: Toxic to humans, soc, highly malleable, ducNle (not so commonly used anymore) Tin: Very rare today (generally only decoraNve), silvery-‐white meTle, malleable, somewhat ducNle Titanium: Very expensive, occasionally used as a cladding system, quite thin, excellent corrosion resistance, high strength to weight raNo Bronze: Alloy used. Mixture of copper and Nn, corrosion resistant and hard, used for springs Brass: Tough, typically used for handles, taps, relaNvely low melNng point, quite easy to work with
Glossary
RaNer: A sloping beam used to support a roof covering, it is part of the internal framework of a roof. Purlin: A horizontal beam running along the length of a roof, supports racers Can>lever: A protruding beam or girder that is fixed only at one end Portal Frame: A simple structure, usually consisNng of two columns, connected at the top by a third member Eave: The boTom overhanging edge of a roof Alloy: Two or more metals combined Soffit: The underside of a structural component or architectural structure Top chord: The top beams in a truss (inclined or horizontal)