Week 1 W01M1: Introduction to Materials -
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Strength : e.g. Steel > timber Stiffness Shape : mono-dimensional/bi-dimensional/tri-dimensional Behaviours : isotropic or anisotropic Economy : price + availability Sustainability
W01S1: Load Path Diagram Applied load: Dead load + Live load Load path diagram shows how a load is transferred down to the ground. - Loads take the most direct routes to the ground - They go in both directions - For every force there is a reaction force to keep the structure stable. - Reaction forces are equal but opposite direction to the applied load.
W01: “Walking the Constructed City” –Dr Margaret Grose Melbourne
Sydney
-Bluestone/Basalt cobblepaths formed from volcanoes in Victoria.
-Abundance of sandstone structures due to high numbers of sandstone quarries.
-Dark colouring of the city due to dominance of basalt.
-Light colouring of the city due to sandstones.
-Wheel ruts from 19th century cartwheels. ‘Bubble marks’ from lava flow. -St. Paul’s Cathedral: basalt foundation but mostly sandstone. -Interchange between clean and rough bluestones showing a change in road level over time.
Perth -Clay, bricks and limestone.
W01: Tutorial Universal Column:
Universal Beam:
Scales 1:1000 – used to pin point location on maps 1:500 – ditto 1:100 – plans, elevation, section 1:50
1:20> – construction details Two types of mass construction: Small module
Large Module
-uses mud/clay (adobe, bricks, concrete blocks)
-uses mostly precast concrete
-alignment of bricks makes bonds and allows for creating shapes and patterns.
Bricks
Concrete Blocks
-made off-site through baking clay in moulds
-precast -quicker in manufacture and laying
-pressed brick: variations in colour due to spread of heat -extruded bricks: wire cut bricks, more uniform in shape and colour -slow process in making and requires expensive labour for laying
-can be manufactured at the same time along with other processes -harder to make shapes and patterns in buildings
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-length is 10mm more than double the width to allow for mortar.
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*: http://www.stegbar.com.au/~/media/Images/Stegbar/about%20windows%20and%20doors/brick_std.gif **: http://www.recoore.com/hardware/images/detailed/1/Concrete_Block-02137484473251f2773c06bdf.jpg
W01: Ching Reading Static Loads Applied slowly to a structure until it reaches its peek unit without fluctuating rapidly in magnitude and position. Live loads compromise any moving or moveable loads on a structure. E.g.: occupancy loads, snow loads, rain loads, impact loads
Dynamic Loads Applied suddenly to a structure, often with rapid changes in magnitude and point of application. Wind load: -
May cause long, thin structures or membrane structures to flutter. Requires measure to prevent sliding, uplifting and overturning
Earthquake load (due to seismic force)
Forces A force is any influence that produces a change in the shape or movement of a body. It is considered a vector quantity possessing both magnitude and direction. Collinear forces occur along a straight line and the vector sum is the sum of magnitudes. Concurrent forces have lines of action intersecting at a common point, the vector sum is equivalent to the application of the vectors of the several forces. Non-concurrent forces have lines of action that do note intersect at a common point, the vector sum of which is a single force that would cause the same translation and rotation of a body as the set of original forces.
Week 1 Studio Activity
To the side is a photograph of the model my group pieced together in week 1 studio. It is a mass construction building model aimed to extend vertically as tall as possible. It is based on the concept of modern skyscrapers with a larger, solid base to lower the centre of gravity allowing for the tower on top to extend tall. Two types of material are used in making this model, rectangular MDF blocks and rectangular bricks. The bricks are used in higher levels of the base to apply compression onto the lighter blocks below and keep them in place.
This is a photo of Bayoke Sky Hotel in Bangkok, Thailand. The shape of our structure greatly resembles this modern skyscraper where the base is strongly reinforced for the tower to stand tall.
http://i2.cdn.turner.com/cnn/dam/assets/130124160413-skyscraper-hotels-baiyoke-bangkok-horizontal-gallery.jpg
Week 1 Studio Activity
The upper layers of the structure is built with a 3x3 block alignment facing different directions so that the blocks create a bond in between and the path of load is not simply going directly downwards.
The above sketch shows the main load path of the tower into the ground. The blocks along the middle of the building are essential in the transfer of load while the blocks unmarked are the ones that do little to support the structure and, as later proven, can be removed without causing the structure to collapse.
Week 1 Studio Activity
The two photos above are examples of work done by other groups. Both models have a similar difference to my group’s tower being that the general shape of is circular. These structures have thinner walls surrounding the space as opposed to thicker walls as my group employed. While this limits the ability for the structure to sustain great height, it certainly allows for making shapes and patterns. (curved walls)
Week 2 W02S1: Structural Systems Solid Systems
Surface Systems
Skeletal Systems
-compression
-‘shell’ structure
-frame structure
Membrane Systems
Hybrid Systems
-covers large areas cheaply and efficiently -less used in built structures
W02: Structural Joints Roller Joints – only resist vertical forces
Pin Joints – can resist horizontal and vertical forces
Fixed Joints – resist horizontal, vertical and rotational forces.
W02: “Column and Wall, Point and Plane” – Dr Alex Selenitsch Column and wall
http://upload.wikimedia.org/wik ipedia/commons/d/de/AlAzhar_Mosque,_Cairo,_Egypt8.j pg
Point and plane – starts with a point, then becoming a line, the line further extending into a plane, the plane folding and bending to become a volume. Differences: column and wall have a clear demonstration of structure and construction while in point and plane it is sometimes unsure what is structure or simply spatial division.
W02: Tutorial (Material) Concrete = cement + water + fine aggregate + course aggregate Compared to: Mortar = cement + water + fine aggregate Base metal – aluminium/bauxite Non-base metal – alloys (e.g. bronze = copper+zinc)
W02: Ching Reading Structural System Superstructure: vertical extension of a building above the foundation Columns, beams, and loadbearing walls support floor and roof structures. Substructures: underlying structure forming the foundation of a building.
Enclosure System Roof and exterior walls shelter interior spaces from inclement weather and control moisture, heat and air flow. Dampen noise and provide security and privacy. Doors provide physical access. Windows provide access to light, air and views. Interior walls and partitions subdivide the interior of the building into spatial units.
Mechanical Systems Water supply, sewage disposal and electrical systems. Heating, ventilating and air-conditioning systems. Vertical transport systems. Fire-fighting systems. Waste disposal and recycling systems.
FACTORS Performance Requirements Aesthetic Qualities Regulatory Constraints Economic Considerations Environmental Impact Construction Practices
Week 2 Studio Activity Activity Overview This week’s studio activity requires us to build a structure out of thin, long balsa strips. The objective was to build a stable tower as high as possible within the given resources. My group’s plan was to create a triangular prism-shaped tower that extends vertically upwards. The photos (left) show the process in the making of this structure. By first creating an equilateral triangular base, vertical columns are added to each of the edges which connect to a second triangular plane and so forth. The building of this tower employs the frame system learned in the E-learning materials in week 2. As the tower’s body is mainly hollow, diagonal bearings are included to help resist external forces as discussed in the previous week. In this context, the main problem is the wind force (disregarding possible occurrence of collusions) which might cause the structure to collapse. Single bracings are placed in different directions at each side due to limited resources. As a result, in each section, one edge gets the most support; one edge receives medium support while the last gets least support. This pattern rotates for each of the four sections so that each side would receive some extent of support against wind forces. It is proven at the end that this method works well as the structure is able to withstand light forces acting from each direction.
Week 2 Studio Activity Structure Overview This is a frame structure made out of balsa strips connected together by tape. The area size of the tower is uniform vertically through the body of the structure, only decreasing to a tip point at the very top. The equilateral triangular shape of the tower helps place the centre of in the middle of the horizontal plane so that all sides are equally resistant to overturning forces. Due to the structure bring hollow within the frame, bracings are included on each side to help withstand forces.
At each of the four sections that made up the main body of the tower, bracings are placed in different directions.
After the main body of the tower is done, a final addition to the top of the structure is a pyramid tip with a long vertical pole extending out to reinforce the height.
The width of each side is half the height of the section. The diagonal bracing is slightly longer than the height.