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Constructing Environments Logbook Week 1- Tutorial and E-Learning notes: Materials: •
Strength- Strong or weak (steel is strong timber is weak)
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Stiffness- Stiff, flexibility (stretchy or floppy)]
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Shape- Linear, planar (sheets) or volumetric (brick)
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Material behaviors- isotropic (bends all ways) or anisotropic
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Economy and sustainability- how expensive, impact on of the environment, how far to transport it (Timber readily available in Australia)
Basic structural forces •
“A FORCE is any influence that produces a change in the shape or movement of a body.”
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Tension forces- where something is pulling either end of a particular material and it stretches or elongates the material
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Compression force is the opposite where something pushes against the said material and the material compresses, buckles or crushes together. Creates shortening of material
Load paths: •
Dead loads- permanent loads
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Live loads- something applied
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Load takes the most direct routes to the ground
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At the ground the applied loads have a reaction which means the whole structure is stable
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Equal and opposite to the applied loads
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Types of Construction: •
Mass Construction -
Forces from the weight of the elements transfer to the foundations from walls and pressures.
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Footing is the forces of the earth.
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Static structures- Where the applied forces have to be equal to the resisting forces (Equal and balance)
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Static structures are resisted by the earth and the man-made footings support the wall
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FramesBeam Column
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Tensile- Fabric structures (where tension is created to hold and lift fabric in place.) Example: A white canvas piece of fabric held together in four places creating tension, therefore holing the canvas up.
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Scales: 1:500 and 1:1000 are generally scales used to actually locate the building or area on a map. 1:100 are generally the basic characteristics of a building. These basic characteristics include the plans of the building (birds eye view), the sections (the vertical cut through a building and the elevation (the sides or walls)
1:50 and 1:20 scale is more detailed and outlines things such as windowsills and how they are connected to the walls, roof, floor etc. This is a critical construction-planning step. 1:10 and 1:5 scales are the minor details for example how the bricks relate to one another and how the windows are connected the wall.
Terminology: UB- Universal beam UC- Universal column PPP- Public Private Partnerships PFC- Parallel flange channel What is MDF- The process of chipping timber into small particles and fine timber fibers then compressing then and gluing them together to create a board.
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Mass construction:
Weight and gravitational forces pushing into the ground
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Two types of mass construction:
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Small modules -
Mud/clay/adobe
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Bricks- baking the clay and changing the composition
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Concrete blocks
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Small module construction has a bond where materials are knitted together e.g. the pattern of bricks.
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Small module construction has the ability to create shape and curve.
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Small module construction has to be insitu, where everything is built on site. This can be very time consuming, expensive and slow.
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Large modules- Precast concrete is used. -
Precast concrete is made off-site which therefore makes it cheaper.
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It is quicker and easier to assemble.
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It is also done in a quicker amount of time therefore workers can be focusing on other jobs around site.
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There are also limitations as to the truck size and machinery size as to how big the precast concrete can be.
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Also precast concrete can’t create shapes or curves (or very difficult and expensive to)
Bricks- Made from clay then baked and made hard. •
Pressed bricks are formed in molds then pressed and compressed and baked. -
There can be a variation in pressed bricks depending where it is placed in the oven and how much heat is it receiving.
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Extruded/ wired bricks -
Composition will the same and there is a lot more consistency.
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Different manufacturing system
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Cooked on a conveyor belt, there is constant heat.
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Glossary: •
Load path-The load takes the most direct routes to the ground. At the ground the applied loads have a reaction, which means the whole structure is stable. There are equal and opposite of applied loads. There are dead loads and live loads.
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Masonry- Masonry refers to building with units of various natural or manufactured products. The units together act as a monolithic whole
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Compression- Compression force is the opposite where something pushes against the said material and the material compresses together. Creates shortening of material
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Reaction force- Equal and opposite reactions, which means whole structure is stable.
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Point load- A point load refers to a point where a bearing or structural weight is intense and transferred to the foundation
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Beam- Generally a horizontal element designed to carry weight load using its bending resistance- Creates compression and tension
Constructing brick task: These were very rough sketches of some of the ideas our group were discussing and talking about. We thought about a circular structure and also more rectangular and square shaped structures.
We then continued to build our circular structure using some of the more heavy bricks in between every 4 or 5 layers to create weight therefore creating a more stable and heavy structure. We then started to lay more wooden blocks around the sides to create more of a curve and to try and create a cave. I think we unfortunately did not quite succeed because we already built our first wall so high that it would be quite hard to create a dome and curve over to create an enclosed space. We ran out of time by the end so didn’t get to build the walls up high enough to reach the other wall and therefore couldn’t attempt to close over the roof.
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Week two tutorial and E-Learning notes: Structural systems: •
Solid systems- early buildings generally using clay/mud/brick
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Shell systems- surface
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Skeletal- frame systems- efficient in transferring loads to the ground
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Membrane and hybrid- good for covering larger areas
Construction Systems: •
Performance requirements- structural compatibility, fire resistance, comfort, insulating, protection, sound, maintenance
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Aesthetic qualities- proportions, colors, surface qualities
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Economic efficiencies- affordability- initial cost and the life cycle cost
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Environmental impacts- embodied energy, efficient materials
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Constructability- labor, site access, in situ or off site
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ESD (Environmental sustainable design) •
Building management- air-conditioning/ lights
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Building is like a filter to the environment- consuming energy, water, electricity
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Embodied energy that goes into the construction and operation of the building- transporting, sourcing, installing products and materials
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Life cycle- the sourcing of materials, distribution of materials, buying and then installing and the wastage of materials
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Recycled materials within a building
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Common ESD strategies: local materials, material efficiency, thermal mass, night air purging, solar energy, wind energy, cross ventilation, smart sun design, insulation and water harvesting
Structural systems: •
Roller joint- only resist vertical loads
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Pin joint- Can resist vertical and horizontal forces but can’t resist rotation
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Fixed- Can resist vertical, horizontal and rotation
Structural systems: Primary member generally spans the shortest
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Secondary member runs longest but only in between the primary (major) beams. Secondary member runs over primary member.
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Truss- Makes a beam lighter -
This is generally used in bridges to make the bridge itself lighter by cutting “holes” and only using the necessary materials to hold it up
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Concrete- Made from water (something to react), cement (the glue) and aggregate (fine aggregate- sand and course aggregate is rocks/stone or marble) -
Mortar- What glues the bricks together and its made from the same materials as concrete except no course aggregate
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Perpend- a vertical mortar joint
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Stability- triangulation, ridge joint, shear panel (fix a sheet of material to the frame)
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Glossary•
Structural joint- Connections joining the precast elements to each other and to other parts of the structure are critical for the overall performance of the building.
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Stability- 3 ways to stabilize a building: triangulation, ridge joint and shear panel (fix a sheet to the frame)
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Tension- Where something is pulling either end of a particular material and it stretches or elongates the material
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Frame-The outside regions of a structure that create the silhouette of it. Generally a wall.
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Bracing-Serving to brace a structure, points of support
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Column- Columns are generally vertical, holding and supporting something. Vertical elements: walls, columns, piers
Constructing task 2: We had to build the tallest structure using MDF board and we were able to cut the board up into as many pieces as we like. Unfortunately we cut the board in the shortest way rather than the longest so we had to tape the short pieces back together to make a longer piece, which made it already very flexible and bendy.
We then created a triangular frame and built beams up and created another triangle. We were not successful because our poles were too thin and it couldn’t carry the weight of the other triangular structures. If our poles were thicker our overall structure would have been successful. We used bracing throughout our structure, which did work initially, but then the building got too heavy. The board cuttings started to bend and curve because it was a flexible material and very thin, weak and easy to break.
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Week 3 E-Learning and Tutorial notes: Structural elements: •
Based on loads to be carried, materials used and form and shape chosen for the element
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Strut: A slender element design to carry load parallel to its long axis. The load produces compression- columns
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Tie: A slender element design to carry load parallel to its long axis. The load produces tension- cable ties for a bridge
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Beam: Generally a horizontal element designed to carry weight load using its bending resistance- Creates compression and tension
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Slab/plate: A wide horizontal element designed to carry vertical load in bending usually supported by beams
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Panel: A deep vertical element designed to carry vertical or horizontal load
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Footings and foundations:
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Static design- how buildings don’t move
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Foundations are found at the bottom of buildings where the building meets the ground- loads need to be transferred into the footings
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Foundation is half the substructure of the building
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Loads on foundation are consisted of dead and live loads (dead- permanent, living- wind, furniture, people)
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Settlement: Buildings sinking a little into the earth
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Shallow footings: soil conditions are stable (most houses)
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Deep foundations: soil conditions are unstable- or very tall/heavy building
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Raft foundation: Provides increased stability by joining individual strips together as a single mat
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Retaining walls and foundation walls: Are used when sites are excavated to create basement or where changes in site levels need to be stabilized. The pressure load of the each behind the wall needs to be considered to prevent the wall from overturning.
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Pad footings: Help to spread a point load over a wider area of ground (skyscrapers)
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Strip footing: Loads from a wall or series of columns spread in a linear manner (more common)
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Shallow footings: soil conditions are stable (most houses)
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Deep foundations: soil conditions are unstable- or very tall/heavy building
Images from Ching Chapter 3 representing deep and shallow foundations
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Mass construction: •
Stone, earth, clay, concrete
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Strong in compression but weak in tension
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They are hard and strong materials, not clay-they weather easily
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Good thermal absorption
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Modular: clay bricks, mud bricks, concrete blocks, ashlar stone
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Non-modular- concrete, rammed earth, monolithic stone
Masonry materials: •
Masonry refers to building with units of various natural or manufactured products
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Bond: the pattern or arrangement of the units
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Course: A horizontal row of masonry units
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Joint: the way units are connected to each other
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Mortar: Mixture of cement or lime, sand and water used as a bonding agent
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Masonry properties: The units together act as a monolithic whole
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Vertical elements: walls, columns, piers
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Horizontal elements: Beams, lintels, arches
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Spanning enclosing elements: Vaults, domes
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Center of massLoad diagram
Structural concepts •
Centre of mass: Point which an object is balanced- entire weight of an object is concentrated as a point
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Equilibrium: State of balance or rest resulting form the equal action of opposing forces- as each structural element is loaded its supporting elements must react with equal but opposite forces
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Equilibrium=object means that the sum of the applied and reaction forces must be zero is order for equilibrium to exist
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Moment of forces- the tendency to make an object or a point rotate
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Moment- force applied at a distance- wanting to rotate- bigger the distance the bigger the movement
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Equilibrium- Equal and opposite force resisting the rotation
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Moment of forces
Bricks: •
230 long x76x110 high
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3 main types: extruded and wire cut, machine molded, hand made
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Joints: 10mm wide (mortar joints)
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Properties: Hardness, fragility, ductility, flexibility (sturdy material but cant be shaped easily)
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Absorbs water over a long period of time
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Poor conductor of heat and electricity
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Reusable and recycled
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Tend to be locally produced, firing adds to its energy consumption
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They can be joined with water based mortar
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Over time if they absorb water they can expand
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Bricks need an expansion joint (because they expand)
Joinery’s
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Sizing and labeling of a brick
Various ways bricks can be layered and arranged
Concrete block with web and hollow cell
Concrete blocks: Manufactured from cement, sand, gravel and water •
Hollow or solid, different sizes
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Mainly used in the construction of walls both load bearing (structural) and non-load bearing (dividing and decorative walls)
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Naturally absorbs water into the pores
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Poor conductors of heat and electricity
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Generally cost effective but labor intensive
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Concrete tends to shrink over time while clay bricks tend to expand
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Movement joints are required for each material- which allows the bricks to expand
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Concrete needs contraction joints because they shrink
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Diagram of a concrete block
Stone: •
3 different types: -
Igneous- formed when molten lava cools (granite, basalt, bluestone),
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Sedimentary- formed when accumulated particles are subjected to moderate pressure (limestone, sandstone),
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Metamorphic- formed when sedimentary or igneous stone is subject to high pressure (marble, slate)
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Hard, big block, not fragile, poor conductors of heat and electricity
Rubble stone
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Glossary: •
Moment-Force applied at a distance, which means it wants to rotate, and the bigger the distance the bigger the moment.
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Retaining wall-A wall that holds back the earth or water
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Pad footing-Supporting a point load (generally a concrete stump/ e.g. skyscraper)
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Strip footing-Concrete poured in a strip (generally more common)
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Slab on ground-
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Substructure-An underlying or supporting structure
Week 3 observations of buildings 1888 Building-Made from insitu concrete, no bracing is used instead rigid joints have been created, stele framework is used, there is a basement underneath, columns and beams are used, it is located next to a low bearing brick building
Bluestone footings, solid brick wall, low-bearing brick wall, basement underneath because you can see the air gaps, 6 bricks thick. Car park- Insitu concrete, column and slab are used, roots of the tree are located in the column holes, the columns are curved in 2 directions. Low bearing stone and brickwork, the bricks are being locked together in the wall creating a vault, the weight is being transferred into the column but the column is also made thicker to support this weight and stop movement.
Week 3 Lecture 3 •
Olympic Park- Catalyst for urban regeneration
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London-canal network
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Expensive to move soil around- reshape while existing
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Too much money spent on one part of London-politics
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Landscaping for the park was the whole development- productive, seasonal
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London used eight times less carbon than Beijing for Olympics.
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Week 4: E-learning and Tutorials •
Span- The distance measured between two structural supports. Span can be measured between vertical supports (for a horizontal member) or between horizontal supports (for a vertical member.)
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Spacing- The repeated distance between a series and similar materials (the shorter distance.) Spacing is associated with supporting elements (such as beams, columns etc.) and can be measured horizontally or vertically.
Floor system showing the different structural elements
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Floor systems
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Steel, concrete and timber floor systems
Floor and framing systemsConcrete, steel, timer.
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Slabs- To span between structural supports. Spanning from beam to beam. One way or two way spans
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Steel framing- Utilizing heavy gauge structural steel, and light gauge steel framing. Sometimes combine with concrete slab systems- able to cope with fires
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Timber- Timber floor framing systems use a combination of bearers (primary beams) and joists (secondary beams). The span of the bearers will determine the spacing of the stumps and the spacing of the bearers equals the span of the joists
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Steel framing: Steel framing systems take various forms, with some utilizing heavy gauge structural steel members and others using light gauge steel framing. -
Steel framing systems sometimes combine with concrete slab systems to where the particular benefits of steel framing and shallow depth floor slab systems are desired.
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Concrete •
Cement, fine aggregate, coarse aggregate and water
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Too much water-final concrete will not be strong enough
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Too little water- final concrete too stiff and not workable
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Concrete is plastic before it sets- means it can be formed into a variety of shapes before it sets. Formwork- temporary forms or molds used to hold liquid concrete in place until it becomes hard.
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Wall formwork- Spreaders keep formwork apart and formwork ties holds certain parts together
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Reinforcement- Concrete strong in compression but weak in tension. Steel is added to make it strong in compression and strong in tension. Put in place where high tensile loads are expected to be placed. Reinforced concrete for fixed joints.
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Not completely waterproof- cover over the reinforcement
Beams and Cantilevers
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Insitu concrete •
Concrete that is cast on site and poured into the formwork and cured on the building site
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Used in footings, retaining walls and all non-standard structural elements
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Construction joint- Divide the construction into smaller and more manageable sections of work
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Control joints- The absorb the expansions and contractions that thermal variations cause so the big mass of concrete doesn’t crack over time
Precast concrete •
Has been fabricated in a controlled environment and then transported to sit for instillation
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More standardized outcome and allows work on site to progress on a faster scale, workers are able to progress on site at a much faster rate
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Commonly used in retaining walls, walls and columns but needs to be held into place until everything is in place. Rarely used in footings.
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Construction joints- Where one precast element meets another and joins naturally
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Structural joints- Connections joining the precast elements to each other and to other parts of the structure are critical for the overall performance of the building.
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Joints- Greatly depend on desired aesthetic outcome
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Limitation in size due to transport, on site changes are very difficult to do
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Ching textbook Page 5.13 showing the process of pre-cast concrete and the construction of it
Glossary: •
Joist- A length of timber or steel supporting part of the structure of a building, typically arranged in parallel series to support a floor or ceiling
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Steel decking- A steel flooring system
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Concrete plank- The artificially roughened plank can be designed as a continuous flooring system by the use of additional reinforcement in the topping concrete over supports
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Girder- A large iron or steel beam or compound structure used for building bridges and the framework of large buildings.
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Week 5- E-Learning and tutorial notes: Walls, grids and columns •
Walls- can be major structural component- carry the loads down from the roof to the ground
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Wall systems 3 types-
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Structural frames (concrete frames-used as a grid of columns with concrete beams connecting the columns together, steel frames- use a grid of steel columns connected to steel girders and beams, timer frames-grid of timer posts or poles connected to timber beams)
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Load bearing walls (concrete- using either in situ or precast concrete to create load bearing walls, masonry- from core filled hollow concrete blocks or grout filled cavity masonry)
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Solid masonry- created with single or multiple skins of concrete masonry units or clay bricks (garage)
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Cavity masonry- formed from two skins of masonry
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Weep holes in bricks- lets the water out
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Stud walls (light gauge steel framing, timber framing) (brick veneer construction- 1 skin of non-structural masonry and 1 skin of structural frame wall)
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CHS- Circular hollow sections, RHS- rectangular hollow section.
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Timber: •
Sapwood- the wood used for timber
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Grain direction- determines the structural performance of the wood (strength and stiffness- strong parallel to the grain)
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Weak perpendicular to the grain
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Seasoning- removing water from the vessels of wood- strengthens the timber. Can do it by air drying (slow), or by kiln drying
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Softwoods- pines, Douglas fir
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Hardwoods- Victorian ash, brown box, Tasmanian oak, balsa wood
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Timber properties and considerationsgenerally quite hard, not very fragile, high flexibility, medium plasticity, poor conductor of heat and electricity, can be re-used and recycled, low embodied energy, generally cost effective.
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Knots- weak points, cause slope of grain
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Protection from insect attack, sunlight and heat, fire, chemical exposure.
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Gehry’s own home: •
Everyday materials- work hands on with materials he found on the streets of LA e.g. chain link, metal sheet, and cardboard.
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Wrapping- came from the things that wrap more precious objects- packaging. Wrapping his buildings in everyday lightweight wrapping materials.
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Collisions and fragments- Collage of unexpected geometry
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Under construction- Reminded him of something that is unfinished, always holding the possibility of change
Engineered timber products •
LVL- Laminated veneer lumber- used for mainly structural beams, posts, portal frames
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Glulam- Glue laminated timer- used for mainly structural beams, posts, portal frames
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CLT- Cross laminated timber- used for structural panels (horizontal and vertical)
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Plywood- Structural bracing, structural flooring, formworks, joinery
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MDF- Medium density fiberboard- non-structural applications (joinery)
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Chipboard and stranboard- used as post of structural systems e.g. flooring
Short and long columns: •
Short, think columns are subject to failure by crushing rather than by buckling
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Long, slender columns are subject to failure by buckling, rather than by crushing.
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Frames: •
Frames need to be capable of resisting both forces and moments to become rigid frames
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Applied loads produce axial, bending, and shear forces in all members of the frame because the rigid joints restrain the ends of the members from rotating freely.
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Fixed frame- connected to its supports with fixed joints
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Hinged frame- connected to its supports with pin joints
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Three-hinged frames- two rigid sections connected to each other and to its supports with pin joints
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2 types of brick walls: •
Brick cavity: 1 layer of brick (110mm), 1 cavity (70mm), 1 layer of brick (110mm)= 270mm
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Brick veneer: 1 layer of brick (110mm), 1 cavity (70mm), 1 piece of timber (90mm)=250mm
We had to make a section of a building using architectural drawings. We firstly measured all the beams, columns, joists, trusses and distances between them all. We then converted these measurements into the correct scaling measurements. We then assembled and cut the balsa wood.
Glossary: •
Stud- The vertical elements inside a wall framing system.
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Noggin-The vertical timber joist on a wall that prevents buckling of the timber
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Lintel- A horizontal member of an opening e.g. a door, window.
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Axial load- refers to the force acting or administered along the lines of an axis of an object. It is expressed as compression or tension and may be as a result.
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Buckling-
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Seasoned timber-The removal of water from the vessels of wood, which strengthens the timber. Can do it by air drying (slow), or by kiln drying
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DPC- Damp proof course (malthoid)- stop water coming up through the ground and entering walls.
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Weep hole- Stops rainwater from soaking into walls.
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