Log Book Interim Submission - Antigone Gougoussis 641138

A01 LOGBOOK CONSTRUCTING ENVIRONMENTS (ENVS10003)

ANTIGONE GOUGOUSSIS (641138)

WEEK 1 E-LEARNING AND READINGS The e-learning and Ching readings this week introduced the concepts of loads and load paths (including static, dynamic, wind and earthquake loads), basic structural forces and materiality. Diagram 1.1 (below) shows the interrelatedness of loads, forces and materiality.

Diagram 1.1 Loads, Forces and Materiality

LOADS Structural Systems of buildings need to support 2 types of loads: 1. Static – applied slowly to a structure without fluctuating rapidly in magnitude or position, where structure responds slowly to deformation 2. Dynamic – applied suddenly to a structure, usually with rapid changes in magnitude and developing inertial forces in relation to mass

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Load Paths  applied loads take the most direct route in order to reach the ground, where the reaction force is equal in magnitude and opposite in direction in order for a structure to remain stable.

Diagram 1.2 Load Path Diagram

INTRODUCTION TO MATERIALITY When deciding which material to use in construction, things to consider include strength, stiffness, material behaviours, shape, economy/budget and sustainability.  STEEL – Strong in both tension and compression, but more expensive than timber.  WOOD – Much weaker in tension and compression than steel, but more readily available in Australia.  BRICK/CONCRETE – Very strong under compression, but weak under tension (needs steel reinforcement if it going to be used in construction and put under tension forces).

(Left to right) Steel, concrete and timber

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TENSION AND COMPRESSION Tension – forces that stretch/elongate a material (when an external load pulls on a structural member) – depends on stiffness of material, C.S.A. (cross sectional area) and magnitude of the load Compression – forces that push/compress a material – opposes tension force

Diagram 1.3 Compression and Tension

STUDIO SESSION ACTIVITY REPORT: ‘COMPRESSION’ TASK: In the first studio session, we were places into groups and asked to construct a tower from wooden building blocks in order to help us understand the behaviour of mass construction and the ways in which loads are transferred through the structural members in compression structures.

PROCESS AND DISCUSSION: 1. My group decided on our first layout of placing the blocks vertically as columns to help achieve height with our tower. Soon we discovered that this structure was extremely unstable as the loads of the applied blocks were being unevenly distributed through the structural members.

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2. Structural members placed in different ways as tower construction was rushed while attempting to curve the walls of the structure. This led to loads being unevenly distributed through the structure and instability of the tower. Therefore, we changed our design concept.

Diagram 1.4 Initial Tower Structure

3. New attempt was made with curved walls and new design layout of blocks in order to distribute the applied load of the blocks as equally as possible through the structural members.

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Diagram 1.5 Final Tower Structure

4. Our final tower design allowed for all loads to be distributed equally through structural members. Although our final tower attempt wasn’t as high as we had hoped for, we managed to create a tower able to withstand compressive forces created by applied loads. We tested the strength and sturdiness of our tower by placing heavy objects on top of its roof, which it was easily able to carry.

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Diagram 1.6 Forces on each block for Final Tower

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By applying loads on top of the structure, this allowed for structural members to be under compression and tension forces. The roof of our structure was hurried and did not follow the base and main body of our tower’s structure.

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However, the layout of our tower allowed for the loads causing these forces to be transferred equally throughout the structural members, therefore reducing the magnitude of the compressive forces on each block.

This allowed for a strong and sturdy final structure.

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WEEK 2 E-LEARNINGS AND READINGS This week, the e-learning modules and Ching readings introduced the concepts of structural form and structural joints. The concepts mentioned throughout the e-learning classroom included the different types of structural systems, the 3 main structural joints used in construction and building, and construction strategies (including ESD strategies and selecting materials).

Figure 2.1 Structural Forms and Joints

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Figure 2.2 Construction Systems

CONSIDERATIONS WHEN CONSTRUCTING SYSTEMS: PERFORMANCE  Need to be easily maintained  building needs to resist wear and tear AESTHETICS  Polished finishes, aesthetic materials  e.g. surfaces for hospitals

ECONOMICS  Affordability  Cost of materials, labour, etc.  life cycling costing ENVIRONMENT  Embodied energy in materials  artificial lighting or natural lighting

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ESD (ENVIRONMENTALLY SUSTAINABLE DESIGN)

Figure 2.3 Common ESD Strategies

STUDIO SESSION ACTIVITY REPORT: ‘FRAME’ TASK: In this week’s studio, we were placed into groups and required to cut up a piece of balsa wood into thin strips in order to create a structure as tall as possible.

PROCESS AND DISCUSSION: 1. The balsa wood was cut into thin pieces. We decided we wanted the pieces to be as thin as possible so we could get as many strips as we could to build our tower to a maximum height.

At the same time, we wanted the strips to be strong enough during the construction process so these structural frame members would not break under the tension forces.

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2. We made the base an equilateral triangle for support and stability while building upwards.

3. The balsa wood strips were found to be very thin and began to bend and break easily when put under small amounts of stress.

4. As we built our tower further, Figure 2.4 Tower top it began to lean to one side as a result of uneven lengths of the structural members. This began to cause problems in stabilising our tower and put certain members under greater stress than other, meaning certain sticks were carrying greater loads. This made certain parts of our frame structure more fragile than others.

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5. We decided to add more triangulated frames in our structure as we built upwards, so that the vertical structural members were less prone to snapping under tension forces. All the joints of our structure were fixed joints, and this caused much stress in the supporting structural members as it prevented all horizontal, vertical and rotational movements.

6. The top of our structure consisted of a pyramid frame structure, in order for all loads to be transferred and equally distributed down members of our towers’ structure.

Figure 2.5 Final Tower Frame Structure

7. Our final tower was very fragile and easy to fall over. I think the frame structure could have been stabilised more by building a much larger base, whilst allowing the tower to become smaller in its cross sectional area as we built upwards. Due to the lightness of the balsa wood material, the structure was easily pushed over.

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8. The structure could have been made more stable by using slightly thicker strips of balsa wood and by measuring our structural member more carefully to create a more symmetrical, stable structure.

Figure 2.6 Possibly Improved design

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GLOSSARY Anisotropic: different physical properties in different directions (e.g. wood – stronger along the grain) Beam: rigid structural members, carry and transfer transverse loads across to supporting elements Bracing: supports to a structure Column: a pillar standing upright, subject to compression Compression: forces that push/compress a material Couple: a force system of two equal, parallel forces acting in opposite directions and tending to produce rotation but not translation Dynamic loads: loads applied suddenly to a structure with rapid changes in magnitude e.g. earthquake and wind loads Earthquake loads: longitudinal and transverse vibrations induced in the earth’s crust resulting from the movement of plates along fault lines (weak spots) Frame: rigid structural members joined at the corners Impact loads: kinetic loads of short duration e.g. from moving vehicles and machinery (static load) Isotropic: Same physical properties in different directions Lateral load: the force acting on a structural member in the horizontal direction, the forces working against a structure e.g. wind pressure against a building Live loads: moving or moveable loads on a structure e.g. collected snow, water or moving equipment Load: the overall force which a structure is subjected to, including mass or weight, externally applied forces (snow, rain, equipment, etc.)

Load path: the path in which a load (applied) will pass through structural members of a structure in order to reach the ground Masonry: building structures using brickwork and stonework Moment: the tendency of a force to produce rotation of a body about a point (clockwise or anti-clockwise direction) Point load: a load applied on a certain point of a beam (load concentrated on a small area of a structural member) Reaction force: forces that are equal and opposite in reaction to the applied forces in order for the structure to remain stable Settlement loads: loads resulting from the subsidence of soil and causing movements in the foundations Stability: being stable, resistant to falling over Static load: loads applied slowly to a structure until it reaches peak value, allowing the structure to respond slowly to deformation Structural Joint: join structural members at a point Tension: forces that stretch/elongate a material (pulls on structural member) Wind loads: the forces exerted by kinetic energy of a moving mass of air (assumed to come from any horizontal direction)

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References: Ching, F 2008, Building Construction Illustrated, 4th edn, John Wiley & Sons, Hoboken, New Jersey.

Gregory La Vardera Architect 2006, Steel Beam, image, <http://blog.lamidesign.com/2006/03/6030-house-floor-beam-day.html>.

Kandla Timber Directory 2014, Timber Beams, image, < http://kandlatimberdirectory.com/>.

Newton, C 2014, W01 m1 Introduction to Materials, YouTube, <http://www.youtube.com/watch?v=s4CJ8o_lJbg&feature=youtu.be>.

Newton, C 2014, W01 s1 Load Path Diagrams, YouTube, <http://www.youtube.com/watch?v=y__V15j3IX4&feature=youtu.be>.

Newton, C 2014, ESD and Selecting Materials, YouTube, <http://www.youtube.com/watch?v=luxirHHxjIY&feature=youtu.be>.

Newton, C 2014, W02 c1 Construction Systems, YouTube, <http://www.youtube.com/watch?v=8zTarEeGXOo&feature=youtu.be>.

Newton, C 2014, W02 s1 Structural Systems, YouTube, <http://www.youtube.com/watch?v=l-JtPpI8uw&feature=youtu.be>.

Newton, C 2014, W02 s2 Structural Joints, YouTube, <http://www.youtube.com/watch?v=kxRdY0jSoJo&feature=youtu.be.> Selenitsch, A 2014, Framework for Analysing Form, YouTube, <http://www.youtube.com/watch?v=KJ97Whk1kGU&feature=youtu.be>.

Online Architecture and Design Exhibition 2014, Concrete Beam, image, < http://www.archiexpo.com/prod/prestasi-concrete-sdn-bhd/prestressed-concrete-i-beams-56829126838.html>.

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