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Cellulose fibres -> FC (fibre cement)-Waterproof to some degree -> CFC (compressed fibre cement)
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Processed Timber a.k.a dressed
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LVL (Laminated Veneer Lumber) -> change direction of grain => stronger (e.g. beams, floor joints) Oregon -> window frames Put holes in beams to make them lighter
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1990s Statutory law -> enforced OH+S regulation -> found in workplace JSA, WMS => written methodology on how they are going to do something Also, builders given legal possession of the site/land when building
Bracing/ triangulation => essence of bracing => increases rigidity Brace in both directions for stability For rigidity => brace, sheer panel (plywood), knee joint, portal frames
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To create a structure from the provided balsa wood that would span 1500mm (1.5m) which would then be able to carry a load. o
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Initial idea to create a triangular truss type span for increased rigidity Ideas of being able to transfer and distribute load evenly across the structure This truss system is seen in many bridges in Australia and internationally Could be considered as a skeletal system as it is frame and has ability to efficiently transfer loads down The piece of wood provided was only 600mm in length and therefore it was decided that the material had to be divided into a minimum of three parts As there needed to be a top and bottom there needed to be a minimum of six pieces It was decided that the pieces would be 1cm in length to allow for enough wood for the top and bottom of the truss in addition to the triangles within the truss
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The bottom and top of the trusses were constructed to be able to span the 1500mm which allowed for some overlap of the materials on the actual structure To construct the top and bottom three 10mm x 600mm pieces of balsa wood were glued and taped together The structure was able to span the require length, however the deflection of the structure was clear visible The compression forces acting above the span and the tension forces acting below the span where creating this noticeable deflection which would give way if extra loads where placed on it
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To increase rigidity of the structure and reduce the amount of deflection the initial truss idea was looked at However, due to inexperience and time constraints the triangular trusses were not able to be constructed To brace the system we added vertical trusses between the top and bottom This also reduced the amount of deflection evident in the structure Upon observing the decrease in deflection, more pieces were added to brace the structure These pieces were also larger in length, but smaller in width in comparison to earlier pieces used It was noted that this also further decreased the deflection Whilst there was still a small amount of deflection, it was less significant in comparison to earlier stages of the process
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The bracing/support of the structure differed from the initial idea, however the idea of concept of bracing was still looked in to This allowed the structure to become more rigid and utilise less materials
o When the structure was tested using a weight being applied on top of it, it failed o The structure began to deflect greatly in the centre of the span due to the weight o The ends of the span also gave way as they were not sturdy enough to support the structure in addition to the added load o There should have been more focus on making the centre of the span more rigid as well as focussing on how to strengthen the ends of the structure which were anchoring the span in place
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In comparison to other groups, our design greatly differed Many groups decided to not include a truss system, but to stiffen and make their structure more rigid in different ways Some groups strengthened their spans by layering the wood on each other to provide a deeper depth The way load was transferred on these structures also differed due to their different design
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However, a common factor in most groups was the failure of their structure during testing Most failed due to the same reasons as my group -> the weakness of the ends of their span
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Green building strategies -> reduce consumption Think about embodied energy Recyclability and carbon footprint Common ESD strategies: local materials, material efficiency, thermal mass, night air purging, solar energy, wind energy, cross ventilation, smart sun design, insulation, water harvesting
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E.g. Council House 2
Roller joints: loads only transferred in one direction, but only when pushed in any other direction, roller just moves -> Vertical loads Pin joints: modes of action can be in 2 directions -> planar Fixed joints: bending can occur
Enclosure/ Envelope System
Structural System
Service/Mechanical System
Structural Systems
Solid -> compression; early buildings e.g. Great Wall of China Surface -> e.g. Sydney Opera House Skeletal -> frame, efficient way of transferring load Membrane -> e.g. sail, sports stadiums Most are hybrid
Bracing: Adding support to a structure to strengthen and stiffen it. Structural Joint: Connectors used to join structural elements
Span: Distance between two points of support
Column: Rigid, relatively slender structural members designed primarily to support axial compressive loads applied to the ends of the members
Ching, F. D. K. (2008). Building Construction Illustrated. (4th ed.). Hoboken: Wiley. Specifier Magazine (2014). Council house 2. Retrieved from http://www.specifier.com.au/projects/offices/34523/Council-House-2.html Tension: External forces pulling on a material. Stretch and elongate the material
Frame: A rigid structure that surrounds something. The skeleton of a building.