FINAL LOG BOOK SE YAN 683646

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concurrent forces moment

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construction systems

construction overview

site analysis

introduction of material

property

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Forces (Ching, 2008, p.2.11) •

• • •

forces: a force is any influence that produce a change in the shape or movement of the body. Forces are vector quantities represented by arrows whose orientation represents the direction of the force and size the magnitude. collinear forces: occur along a straight line, the resultant force is the algebraic sum of the combined forces concurrent forces: have lines of action that intersect at a single point. moment: is a force that causes a body to rotate about a single point.

Material properties to consider: • • • • • •

strength stiffness/flexibility shape material behaviors economy sustainability

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studio 1: mass tower •

• •

In a group of 4 using the MDF bricks to build the tower as high as possible which must accommodate as Godzilla toy In order to accommodate the toy, we decided to leave a door for the tower the tower is built with the pattern of two bricks supporting one brick following the pattern, we tried to form a door when the tower is about 30 cm height because we think the tower might collapse if we form the door when it gets higher forming the door at 30cm height 6

studio 1: mass tower

final version of the tower 7

WEEK 2: STRUCTURAL LOADS AND FORCES

structural concept

structural systems solid

surface

skeletal

membrane

hybrid structural connections roller joint

pin joint

fixed joint 8

construction systems

aesthetic qualities

performance requirements

material regulatory constrains

ESD economic considerations

environmental impact 9

types of structure and connections • • • • • •

• •

solid: brick, stone, good in compression surface/shell frame/skeletal membrane hybrid (mixed) roller joint: allow for rotation but resist translation in a direction perpendicular into or away from their faces. designed for vertical load, move when applied with lateral load, good to cope with thermal expansion (not often used) pin joint: allow free rotation, resist translation in any direction, used for truss system fixed joint: inflexible, does not allow for rotation or translation, and provide both force and moment resistance

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studio 2 •

• •

objective: use the balsa wood and glue to build a frame tower which can reach the roof top for the base of our tower, we use the the fixed joints connection in order to provide better force and moment resistance so that the tower can get higher we use the cross to form the base to make to tower more stable at the top of the tower, we use the similar structure as the base, the tower can withstand the tower of the sticky tape, which is heavier than the tower itself

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WEEK 3 FOOTINGS AND FOUNDATIONS

structural structural concept concept structural structural element element strut strut

tie tie

beam beam

slab/plate slab/plate

panel panel geometry geometry & & equilibrium equilibrium center center of of mass mass moment moment of of forces forces

equilibrium equilibrium and and free free body body diagram diagram 12

Construction systems

Footings and Foundations

strip footings

raft footings deep footings end bearing piles

friction piles retaining and deep foundation walls

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Material

mass mass construction construction (masonry (masonry is is its its subset) subset)

mass mass material( material( strong strong in in compression compression weak weak in in tension) tension)

stone stone

earth earth

clay clay (brick) (brick)

concrete concrete 14

The design of a structural element is based on the loads to be carried, the material used and the form and shape chosen for the element •

strut : a slender element design to carry load parallel to its long axis. The load produces compression (columns of temples tie: a slender element design to carry load parallel to its long axis. The load produces tension (cable of bridge). beam: fixed structural members used to carry and transverse loads across space to supporting elements slab/plate: a wide horizontal element designed to carry vertical load in bending usually supported by beams. panel : a deep vertical element designed to carry vertical or horizontal load (wall).

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Geometry & Equilibrium •

• •

Center of mass: the point about which an object is balanced; can also be thought of as the point where the entire weight of the object is concentrated; the location of the centre of mass depends on the object's geometry (Centre of Gravity) Equilibrium is a state of balance resulting from the equal action of opposing forces. For an object to be in equilibrium, any applied forces must be resisted by equal and opposite forces. These forces are called REACTION FORCES. The reaction forces are developed in the supporting elements. EQUILIBRIUM = OBJECT or SYSTEM AT REST This means that the sum of the applied and reaction forces must be zero in order for equilibrium to exist The moment of a force is the tendency to make an object or a point rotate. Moment = force x distance

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Footings and foundations • • •

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• •

foundation are the substructure of the building and to transfer all loads to the ground must resist the force of the soil settlement: buildings compress the earth beneath them and the buildings tend to sink a little into the earth, footings and foundations should be designed to ensure that this settlement occurs evenly and that the bearing capacity of the soil is not exceeded DIFFERNTIAL SETTLEMENT causes cracking in a building Shallow footings: are used where soil conditions are stable and where the soil bearing capacity is adequate close to the surface of the ground. Deep foundations: are used where soil conditions are unstable or where the soil bearing capacity is inadequate retaining walls and foundation walls: are used when sites are excavated to create basement or where changes in site levels need to be stabilized

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Material • • • • • • • • •

brick: a standard masonry unit made of clay wide variation in the color because clay is a natural material bricks are permeable (non-waterproof) pros: joined with water based mortar; wetness can escape if adequately ventilated cons: expand (movement joists are required); efflorescence caused by the contact with soil concrete block: a standard masonry unit made of concrete, tends to shrink stone: igneous: formed when molten rock (lava/magma) cools. e.g bluestone sedimentary: formed when accumulated particles are subjected to moderate pressure. e.g. sandstorm metamorphic: formed when the structure of igneous or sedimentary stone changes when subjected to pressure, high temperature or chemical processes. e.g. marble 18

Studio 3: tour at the campus

tension

The arch seen above is used to distribute the load of the wall above to either side of the opening. Also, the material they used is sandstone.

At the car park in Melbourne university, we saw the column (strut) which transfer the load to the ground. The column should be strong in compression.

We can see the tie which carry some of the load of the stair. 19

WEEK 4: FLOOR SYSTEMS AND HORIZONTAL ELEMENTS Construction Systems Structural Concepts

floor & framing systems concrete

Beams and Cantilever

steel timber

Material Span and Spacing Concrete

precast

In Situ 20

Span&spacing and Beam&cantilever • • • • •

Span: the distance between two structural support Spacing: the distance between a series of similar elements (measured centre-line to centre-line) spacing depends on spanning beam: a horizontal structural element which is to carry and transfer the loads to vertical supports cantilever is created when a structural element is supported at only one end, which is to carry and transfer loads to the support

floor system • • • • •

Concrete System: slabs (one-way or two-way) slab thickness: span / 30 Steel system: structural steel & light gauge Griders: main beams Timber floor system: use bearers (primary beams) and joists (secondary beams). 21

concrete •

• •

common mix: 1 part cement, 2 parts • fine aggregate, 4 parts coarse aggregate, 0.4-0.5 part water great advantages: fluid and shapeless formwork: temporary support or moulds used to hold the liquid • concrete in place until it becomes hard. It can be built at the building site• - IN SITU - or in a factory - PRE CAST. During CURING PROCESS, the formwork needs to be supported • as the weight of the wet concrete is very heavy (using props and bracings). Reinforced concrete: concrete is • stong in compression but weak in tension, therefore we add steel reinforcement in the form of MESH or • BARS. consideration: concrete is permeable, we should not put the steel bars too close to the surface, otherwise they might get moistures and oxidated; good vibration to get rid of the air bubbles

pre-cast: the concrete element has been made before transported to site for installation; can avoid many quality control issues associated with in situ concrete; faster the progress common used in walls and columns construction joints: joints naturally occur when one precast element meets another structural joints: the connection of the precast elements which are essential for the overall performance of the building construction joints and structural joints depend on the desired aesthetic outcome consideration: limited in size for transport

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WEEK 5: COLUMNS, GRIDS AND WALL SYSTEMS

structural concept

columns long columns

short columns frames

fixed frame

hinged frame

three-hinged frame grids 23

construction systems

Materials

wall systems

structural frames

wood

grain

knots

columns

grid

protection

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Columns • • •

• •

columns are relatively long structural element which carry the axial compressive loads effective length: the distance between inflection points in a column subject to buckling short column: ratio for effective length to its least lateral dimension does not exceed 12, which are subject to failure by crushing rather than by buckling long column: the ratio is over 12 slender ratio: effective length (L) to its least radius of gyration (r). Therefore, in terms of asymmetrical column sections, buckling will tend to occur about the weaker axis or in the direction of the least dimension effective length factor: both ends fixed k=0.5, one end pinned one end fixed k= 0.7, both ends pined k=1.0, one end free and one end fixed k=2

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Frames (Ching, 2008, p. 2.17) • •

• •

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frame: the structural element which can resisting both forces and moments fixed frame: better resistance of deflection than a hinged frame but also rely more on support settlement and thermal expansion; no deflection hinged frame: a rigid frame is supported by pin joint. three-hinged frame: a structural combination of two rigid sections connected to each other and to its supports with pin joints, which is least affected by support settlements and thermal stresses compared to the other two frames. structural frames: concrete frames, steel frames, frames can be stabilized through bracings, bracing sheer walls, making the joist rigid load bearing walls stud walls (non-load bearing)

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Wood •

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grain direction determines the structural performance of wood, strong parallel to grain and stiff parallel to grain, weak perpendicular to grain consideration: knots are weak points which cause slop of grain; water: when moisture percentage of wood > 20% can occur fungal attack, swelling, shrinkage can cause cracks protection against water: avoid exposure; seal (paint); particular care for end grain - seal before assembly protection gainst sunlight and heat: avoid exposure; light colour paint plywood: manufactured by gluing and pressing thin laminates together to form a sheet. (uses: structural bracing, flooring, formworks)

strong

weak

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Studio 5 â&#x20AC;˘

â&#x20AC;˘

objective: use cardboard,foam blocks, foam core, balsa,corrugated card, glue to build the 1:20 scale model of the pavilion's basement firstly we look at the construction plan ( overview and section) to get the basic understanding of the structure

The overview plan

The section plan

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studio 5 â&#x20AC;˘

process

in order to have a better understanding of the structure, the tutor draw a clearer structure for us

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studio 5 we use rigid joints to form the fixed frame for better resistance of deflection. Because it is over the basement, the basement create better support settlement avoid thermal expansion

at the end we run out of the material to make a wall, therefore we create a column instead to transfer the load to the ground

These walls are just used to divide the room for the basement, therefore we consider they are stud walls

These walls are actually carry the load for the buildings, they are the loadbearing walls

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WEEK 6: SPANNINGS AND ENCLOSING SPACE

roofing strategies and systems

structural concept

flat and sloping roof

flat roof trusses

plates

construction systems

structural steel roof framing

space frames

sloping roof

portal frames roof

grids

materials metals oxidation

corrosion

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Trusses, plates and grids ( Ching, 2008, p. 2.16) â&#x20AC;˘

â&#x20AC;˘

a truss is a structural frame relying on the geometric rigidity of the triangle and manufactured by linear members receiving only axial tension and compression. plate structures are fixed, flat, normally consistent structures that disperse loads in a multidirection pattern, with the loads generally following the shortest and stiffest routes to the supports. common e.g. a reinforced concrete slab

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Roof (Ching, 2008, p.6.02-6.03) •

• • •

• •

• •

roof system functions as the primary sheltering element for the interior spaces of a building flat roof: pitched: 1-3 degrees pitched and sloping roof: > 3% concrete roofs: mostly flat plates of reinforced concrete, the top surface is sloped towards drainage points and the entire roof surface finished with applied waterproof membrane structural steel roof framing (Ching, 2008, p.6.06-p.6.07): flat roofs: has both primary and secondary roof beams for heavier roof finishes such as metal deck/concrete. or roof beams and purlins for lighter sheet metal roofing sloping roofs: roof beams and purlins for lighter sheet metal roofing portal frames roof: has a series of braced rigid frames ( two columns and a beam) with purlins for the roof and girts for the walls. The walls and roofs are usually finished with sheet metal

purlins

girts

cross bracing 33

• •

truss roofs: OPEN WEB type steel or timber elements (Ching, 2008, p.6.09). space frames: long-spanning three dimensional plate structure based on the rigidity of the triangle and composed of linear elements subject only to axial tension and compression. the simplest spatial unit of a space frame is a tetrahedron having four joints and six structural members (6.10) gable roof and hip roof

Metal •

• •

consideration: metal will react with other metals by giving up or taking on another metal's ions; to reduce the risk of corrosion metals can be separated by an insulator such as a rubber gasket or kept away from sitting in moisture; some metals cause steel to corrode whereas other metals corrode deferentially themselves thereby protecting the steel. e.g. galvanized steel is steel coated by a thin layer of zinc to protect the steel from rustling; water related damage: oxidation and corrosion protect against water to reduce corrosion: avoid prolonged exposure to moisture; seal against moisture; chemical treatment 34

WEEK 7: DETAILING STRATEGIES 1 construction system

structural concepts

arches

domes

heat

shells

moisture

material

plastic

rubber

paint

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arches, domes and shells (Ching, 2008, p. 2.25-2.27)

arches are bent structures for spanning an opening, made to withstand a vertical load mainly by linear compression; they transform the vertical domes are rounded vault forming the roof of a building or structure, typically with a circular base shells are thin, curved plate structures. A shell can sustain relatively large forces if uniformly applied but it has little bending resistance and is unsuitable for concentrated loads

• •

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Detailing for heat and moisture â&#x20AC;˘ for water penetrate into a building all of the following three conditions must occur: an opening, water present at the opening, a force to move water through the opening; remove any one of the conditions and water will not enter; one is enough but two or more are added just in case â&#x20AC;˘ common technique to remove openings: seal the opening with sealants; gaskets ( e.g. performed shape made from artificial rubbers) â&#x20AC;˘ keeping water away commonly used strategy: 1.sloping roof with gutter; overlapping cladding 2. sloping window, door sill, roof/wall flashing 3. sloping the ground surface away from the walls at the base of buildings

roof tiles

door sill

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Detailing for heat and moisture, material • • Neutralizing the forces (most secure • strategies) • controlling heat: heat gain and heat loss occur when heat is CONDUCTED through the building envelop; the building envelop and building elements • are subjected to RADIANT HEAT sources; THEMAL MASS is used to regulate the flow of heat through building envelope • effective control of heat: saves energy, money and increases comfort levels • controlling heat - conduction: thermal insulation; thermal breaks (made from low conductive materials like rubbers and plastic); double glazing (air spaces reduces the flow of heat) • controlling heat- radiation: reflective surfaces; shading systems • controlling heat - thermal mass: thermal mass can be used to absorb and store heat over a period of time and when the temperature drop, the stored heat is released.

rubber consideration: avoid sunlight plastic consideration: weather (especially sunlight) related damage; avoid or minimize sun exposure; some plastic can expand or shrink easily paints: oil based and water based

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Week 8: OPENINGS

material

structural concepts glass deformation

geometry construction systems

openings

doors

windows

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â&#x20AC;˘

moment of inertia: the structure's resistance to deflection or bending. In order to increase beam's efficiency, which is to offer the required moment of inertia with smallest possible area, we normally make the section deeper.

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Glass glass component • •

formers: the basic ingredient used to produce glass: silica Fluxes: help former to melt at lower and more practical temperature: soda ash; potash; lithium carbonate stabilizer: combine with formers and fluxers to keep the finished glass from dissolving or crumbing two main types: flat glass, shaped glass

float glass is the most common glass • •

production clear float glass: the simplest and cheapest glass product laminated glass: a tough plastic interlayer (PVB) is bonded together between two glass panes. This improves the security and safety of glass product as even though the glass can still crack, the glass tend to adhere to the plastic rather than falling apart tempered glass (toughened glass): ideal to use in highly exposed situations or when the sizes required and particularly large 41

Studio 8: Visiting Oval Pavilion

The 1:1 pop up window sill detail drawing section

The details in actual site is quite different from the details drawing. As we can see the step in the actual site is lower than the step in the drawing

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WEEK 9: DETAILING STRATEGIES 2 Structural Concept

Stress and structural members

long column

short column

joints

beam

roller

fixed

pin

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Construction system

construction detailing

movement joints

health and safety

aging gracefully

repairable surfaces and resistance to damage

cleanable surface

maintenance access

constructability 44

Stress and structural member (Ching, 2008, p. 2.13) • • •

short columns crush when the stress from the axial load is superior to compressive ability of the material in the cross section long columns buckle when experiencing the stress from the axial load applied on the top beams bend and deflect when getting the stress from the transverse loads.

Joints and connections (Ching, 2008, p. 2.30) •

• •

roller joint: allow for rotation but resist translation in a direction perpendicular into or away from their faces. designed for vertical load, move when applied with lateral load, good to cope with thermal expansion (not often used) pin joint: allow free rotation, resist translation in any direction, used for truss system fixed joint: inflexible, does not allow for rotation or translation, and provide both force and moment resistance

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construction detailing: how material are put together • health and safety: fire insulation; disable code; stairs • constructively: easy to assemble; easy to adjust; based on efficient use of construction facility, tool and labor • aging gracefully; repairable surface and resistance to damage; cleanable surface; maintenance access Types of movement joints (Ching, 2008, p. 7.48) • expansion joints: allowing thermal or moisture expansion to happen without damage to the structure • control joints: regulating the location and amount of cracking resulting from drying shrinkage, thermal stresses or structural movement • isolation joints: allowing the differential movement or settlement to happen between parts • monolithic materials: a single material or materials mixed so that the components can not be identified • composite materials: two or more materials are combined in such a way that the individual materials remain easily distinguishable

four main types: fibrous, laminar, particulate, hybrid

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Studio 9: Visiting a commercial site near the corner of William Street and Lonsdale Street The site: New 4 storeys above a existing 20 storey office building

The Gantry near the construction site and the load path diagram The scarfford is used to protect the pedestrians and be storage of the materials

The builders using the tower crane the carry the goods from the ground to the construction site at the top of the building

electric crane tower Considering the building is being used as offices, they are using electric crane which is making less noises instead of diesel crane. The electric crane is more environmentally 48 friendly but taking more time to carry the goods

Studio Session: Visiting a commercial site near the corner of William Street and Lonsdale Street The site: New 4 storey above a existing 20 story office building

The uncompleted floor The concrete is with more air bubbles inside which is lighter and cheaper, considering the site is already at a high level

The air conditioning system under construction They use the self leveling cement to complete the floor work, which fills the small holes on the surface

The completed air conditioning system The fire insulation on the top

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Week 10 when things go wrong

structural concept

Lateral forces

wind forces

earth forces

bracings and diaphragm

shear walls

moment joints 50

construction systems and materials

collapse and failures

suitability

maintenance

heros and culprits

long term performance

construction and detailing

health and IEQ

energy used and embodied energy

waste/recycling/ recycled

pollution

life span 51

Material selection critical issues:  suitability of material for application -exposure -compatibility -strength and deflection  long term performance  maintenance  construction and detailing

Issues to consider when selecting materials: • • • • •

health and IEQ waste/recycling/recycled energy used and embodied energy pollution life span

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Lateral Forces wind forces are functioned at the sides of the exposed areas earth forces are more functioned at the amount of mass above the foundation

lateral load resisting system • • • •

bracings diaphragm shear walls moment joint

Tall, thin slab on the end building is significantly affected by the wind load overhanging awning roofs are also vulnerable to wind large flat roof

• • •

make the building symmetry to resist the earthquake

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Studio 10: 3D drawing of details

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Construction workshop: to design and build a structure that spans 1000mm Material: using 1 pieces of plywood and 3 pieces of pine wood Process:

basic measurement of the material

finishing stablizing

we decided to use one piece of the pine wood to stabilize the other two pieces

attach the plywood at the bottom

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The plywood is good at tension. When load is being applied on the structure, the load was carried and transferred to the bottom. The plywood is in tension and spreading the load across the structure

Finally, the bottom of the beam was broken. Because the nail was located there which creating a weak point, which is very similar to the knots in timber.

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WEEK 3 KEY TERMS • moment: a force that causes the body to rotate about a single point. • strip footing: continuous spread footings of the foundation (Chung, 2008 ,p.3.09). • retaining wall: designed to hold back soil. • slab on ground: A concrete slab serves as footing for a number columns or the entire building. • pad footing: also called isolated footing, to transfer a point of load to the ground. • substructure: foundation of the building. • slurry: A concrete wall cast in a trench to serve as sheeting and often as a permanent foundation wall. WEEK 4 KEY TERMS • Joist: secondary beam • grider: main beam • steel decking: the floor deck serves as a working platform during construction and as formwork for a site cast concrete slab. The metal decking is corrugated to increase its stiffness and spanning (Ching, 2008, p. 4.22) • concrete plank: one-way concrete slab • span: the distance between two structural support • spacing:the distance between a series of similar elements (measured centre-line to centre-line)

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WEEK 5 KEY TERMS • stud: vertically framing member in a building's wall; may carry vertical structural loads or be non load-bearing such as in partition walls which only separate spaces • nogging: a horizontal piece of member in wall framing between vertical studs or beams to give lateral support. • lintel: a horizontal support of timber, stone, concrete, or steel across the top of a window or door • axial load: the force acting or administered along the lines of an axis of an object • buckling: bending of column supporting a compressive load • seasoned timber: dried timber which is less than 15% of moisture WEEK 6 KEY TERMS • rafter: sloped structural members that extend from the ridge or hip to the wall plate, which is designed to support the roof deck and its associated loads • purlin: one of several horizontal structural members that support roof loads and transfer them to roof beam • cantilever: beam anchored at only on end • portal frame: has a series of braced rigid frames ( two columns and a beam) with purlins for the roof and girts for the walls. The walls and roofs are usually finished with sheet metal • eave: the bottom edge of the roof • alloy: a metal made by combining two or more metallic elements, especially to give greater strength or resistance to corrosion • soffit: the underside of overhanging eave 59 • top chord: the top beam in truss

WEEK 7 KEY TERMS • gutter: used to collect the water from the roof and discharge the water downpipe and storm water system. • drip: forms of a wide enough break between two surfaces to prevent the rain from the wall below. • vapour barrier: any material that resist effusion of moisture through wall, ceiling and floor assemblies of buildings and of packaging. • parapet: a low protective wall along the edge of a roof, bridge, or balcony. • down pipe: a pipe to carry rainwater from a roof to a drain or to ground level. • flashing: a strip of metal used to stop water penetrating the junction of a roof with another surface. • insulation: the material used to block moisture and heat. • sealant: the material used for sealing something so as to make it airtight or watertight. WEEK 8 KEY TERMS • window sash: a structure which holds the panes in the structure • deflection: to bend or turn in a straight line • moment of inertia: how difficult it is to change the shape of the object by deflection along a certain axis • door furniture: lock, handles or other features of lock • stress: the pressure applied on the member • shear force: pushing one part of a body in one direction, and another part of the body in the opposite direction

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• • • • • • •

WEEK 9 KEY TERMS sandwich panel: formed by bonding two facings to a thicker core. e.g. precast concrete panels - 2 layers of concrete separated by an insulating core. bending: the deflection of a member. skirting: a block where a base and vertical frame meet. composite beam: a beam combining different materials to work as a single unit, such as steel with concrete, in situ and precast concrete. shadow line joint: a detail where there is a small gap while it is still connected by a joint between 2 members creating a shadow line. cornice: a moulded projection that crowns a wall horizontally divides it for compositional reasons

WEEK 10 KEY TERMS • shear wall: is a structural system made braced panels also known as shear panels to resist the effects of lateral load applying on a structure • soft storey: A multi-storey building where one or more floors above the ground level with large windows, open spaces, especially for commercial purpose. • braced frame: the frame with bracings • life cycle: the length of time of the building is expected to serve its function • defect: a condition that detracts from appearance, strength or durability of element • facia: board used on the outside face of cornice • corrosion: a state of deterioration in metal caused by oxidation or chemical reaction 61 • IEQ: indoor environment quality

Reference list: Ching, F.D. (2008). Building construction illustrated (4th ed.) New Jersey: Wiley.

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Logbook 683646 SE YAN

melbourne university