Week 1:! The paradox of construction: “Before a building is completed, it goes through an incredible amount of complexity. And gradually, as the the scaffolding is taken away, and the construction systems are lined, the building becomes, in its final form, a much more simple and coherent piece of architecture.”! -Clare Newton, Senior Lecturer, Constructing Environments.! ! ! !
A load is a weight or source of pressure borne by someone or something. A load will take the most direct route towards to ground. Every action will have an opposite and equal reaction, and in the the case of loads, the gravitational force reacts, creating a stable structure. !
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! ! Basic Structural Forces!
• There are basic structural forces at work in every contraction project. A force is defined as any influence that produces a change in the shape or movement of a body (Oxford Online Dictionary).! • Forces are considered to be vector in nature, possessing both magnitude and direction. !
There are two basic structural forces including:! Tension: This occurs when an external load forces the particles of a structural member to move apart and thus elongate the material.!
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Compression: This occurs when when an external load forces the inward movement of a structural member’s particle, causing the material to shorten. Otherwise known as the opposite of tension. !
! ! Introduction to materials!
There are several considerations when selection materials in construction.! Strength: Is the material able to support high intensity loads?! Stiffness: Depending on the context of construction, materials must be selected to support the required load/s.! Shape: Monodimensional, linear, planar, volumetric! Material Behaviours: Some materials are equally strong in tension and compression, isotropic (identical properties in all directions), anisotropic (directionally dependent) ! Economy & Sustainability: How readily available is the material and what is it’s cost? What is the materials impact on the surrounding natural and built environments?!
This image conveys the base of our tower. Building a strong base is paramount for a tall construction, as particular load forces cause a shift in the overall balance of the structure. The idea behind our construction was the fact that the blocks were rectangular in shape, and thus a square base would provide the most stable base possible.!
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The bricks were aligned in a tessellated fashion, in order to maximise the height of the tower. This is the simplest repeating pattern in construction, and will create a wall only one-half brick thick. The load which will be applied at the end of the construction will be be stronger, as the blocks do not rely on a single column brick for balance.!
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At this point in the construction, the bricks were slowly angled into the centre, in order to close off the top of the structure. !
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The sides of the tower began to angle in creating a peak. The structureâ€™s strength is significantly improving, as the load spreads through the introduction of some horizontal forces.!
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The finished product of the tower. The structure has stability and the load is much more effectively spread with the formation a prominent peak. In future, constructing a peak which is supported by a pillar in the middle of the structure may eventuate in a tower with greater balance.!
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Week 2:! Construction Systems:! Enclosure/Envelope system! -The encompassing structure of a building, not required to carry a load.! Structural system! -The sub-system of a structure required to maintain load forces.! Service system! -Mechanical, plumbing and electrical systems.!
! ! Structural Systems:!
Solid systems: e.g. Roman arches!
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Shell systems: Planar structure e.g. Sydney Opera house!
Skeletal systems: Efficient in transferring loads to ground e.g. Eiffel Tower!
Membrane systems: Based on the principle of tension e.g. North Court, The University of Melbourne!
Hybrid systems: Combination of structural systems e.g Beijing Olympic stadiums!
ESD. (Ecologically Sustainable Development) Considerations! Embodied Energy: Total energy used during all stages of a materialâ€™s life (Calkings 2009, pg 30).! Life Cycle: Begins with the extraction of raw materials and disposal of waste products into the earth or the recycled into new products! Stages: ! 1. Raw materials! 2. Primary processing and refining! 3. Manufacturing! 4. Delivery! 5. Construction use and maintenance! 6. Final disposal! (Calkings 2009, pg. 24-27).! Recyclability: The potential of a material to be re-used into a new product! Carbon Footprint: Measure of the greenhouse gases generated during the fabrication, transportation and use of a material.!
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Common ESD Strategies!
Structural Joints! Roller Joints: Allows for horizontal movement!
! Pin Joints: Loads force an outward movement of the joint! ! Fixed Joints: No vertical or horizontal movement! !
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*see Figure 1! Source: http://web.mit.edu/4.441/1_lectures/1_lecture13/1_lecture13_pic1.gif
BALSA TOWER A triangular base provides effective support for a tall structure.
The base of the balsa tower remained strong, while the sides of the structure highlighted the inadvertent flexibility of the joints.
From a triangular base, the idea was to create a prism like structure, with triangles mirroring each other. This method of construction was based on the Louvre Museum in Paris.
The structure remains intact.
The mirroring triangles method quickly became ineffective. Balance could not be maintained as the structure became taller.
Finally, the sides of the structure have detached from the triangular base.
Our group fell back to the prism structure. Though not as aesthetically pleasing, this form of skeletal construction would support a greater weight.
A peak was contracted with the remaining balsa.
A load force was sent down the fragile frame of our structure.
The load force caused the structure to lean to one side, as it became evident the pieces of balsa were not all the same length. A load force travels down the shortest possible route.
Week 3:! !
Olympic Constructs! A reflective talk by Alan Pert on the constructive processes involved in the development of the 2012 Olympic Games infrastructure.!
• “We had to create a landscape”- Alan Pert. • The Olympic development fast tracked 25-30 years of planned work into a single decade. • It was expensive to move soil (contaminants, pollution). The soil was cleaned through remediation. • Groundwater was treated, injecting compounds into the ground, generating oxygen to break down harmful chemicals. • Transforming athlete villages into housing post Olympics has become a major issue, due to insufficient pre planning. • Bridges were built to suit the topography. • There was pressure to consider environmental impacts all the way through construction. • Recyclable materials was a new concept explored by the architects and engineers alike.
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Introduction to Mass Construction!
CONCRETE VS. CLAY! -Over time, concrete blocks will shrink, due to water gradually being lost to the atmosphere.! -Clay blocks will expand, as they absorb moisture from the atmosphere.!
Footings & Foundations !
• Foundations are found at the bottom of buildings where the building meets the ground (Ching, p. 302). The purpose of a foundation or foundations is to support the super structure. !
• Foundations allow the super structure to gradually sink into the earth, an inevitable process.! • Shallow footings are used for stable soil. They include:!
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• Deep footings are required for unstable soil. They
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include end bearing piles & friction piles!
Structural Elements! -Strut e.g. Column (Designed to carry load parallel to its long axis (Effective in terms of compression)! -Tie e.g. Cable ties in bridge (Effective in terms of tension)! -Beams (Designed to carry tension)! -Slab (Wide horizontal element designed to carry vertical load, supports by beams! -Panel (Deep vertical element designed to carry vertical or horizontal load)!
References:! Ching, Francis D.K. (2008). Building Construction Illustrated (4th ed). Hoboken, NJ: John Wiley & Sons, Inc.!
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Calkings, M (2009). Materials For Sustainable Sites. Wiley: (1st ed).! Weekly E-Learning content (2014). Retrieved from University of Melbourne -Learning Management System: Constructing Environments. !