Week 1 Learning Summary Introduction to materials and basic structural forces This week being the first week was focused on an introduction into the subject and to basic structural forces, materials and load paths. It became apparent that considering and understanding materials (and their properties) is fundamental in deciding what materials to use in relation to suitability and practicality. Choosing the right materials is particularly important as they determine how a structure will respond to forces. Newton (2014) touched on considerations for selecting materials in the e-learning such as the strength, stiffness, shape, behaviour, economy and sustainability which was further explored during the studio. The studio explored more into how materials and their properties respond differently to forces and how certain materials handle forces better than others. For example, some materials may be better at withstanding compression forces (e.g. mass construction) and others better with tension forces (e.g. Steel, aluminium, wood).
Additionally, there are materials that have a combination of properties that enables the material to withstand compression and tension forces (e.g. reinforced concrete). The reason these materials respond differently is due to their properties, for example concrete or stone are very dense materials making them strong and hard which is good for compression forces but bad for tension forces as they are unable to stretch or bend.
Also introduced this week were, load paths, loads and reaction forces. There are different types of loads including dead loads (static) which are a permanent/long term loads, live loads (applied) and dynamic loads (environmental) all in which create load paths (Ching, 2008, pp2.08-2.09) An example of a load path is shown to the left. As shown, the load path takes the most direct roots down to the ground and is then faced with the ground reaction force which has to be both equal and opposite to the applied load to ensure stability (Ching, 2008, pp2.12).
Week 1 Studio The goal for this week’s activity was to construct a structure as high as possible using MDF (mediumdensity fibreboard). My group decided to construct a structure in a rectangle form with a bonded brick like formation. We decided on this form as we believed it would be the strongest. As shown in images (a), and (b), an un-bonded wall would have had stability issues as the wall would either collapse from lateral force or buckle when an additional load is applied. Whereas, by having a bonded wall formation, the load will be distributed across several blocks allowing the structure to become more stable.
(b) (a)
(c)
(e) Auditorium building: Alder and Sullivan 1889(Architecture 365, 2010)
As we began to build the structure we realised our method was very time consuming and we needed to consider different methods that would enable the structure to be built faster without the sacrifice of stability. We all agreed that by having a solid stable base we could afford for the rest of the structure to thin out in wall thickness and by the amount of blocks (as shown in images (f) and (g)). Much like how the Auditorium building designed by Alder and Sullivan showcased large, heavy load-bearing outer walls predominantly on the first few floors made from rough cut dark granite stone before it thinned out to a lighter material (limestone)(Auditorium Theatre, 2013) (see image (e)). These first few floors acted as the main support due to the materials strength which took on all the compression exerted from the above levels. This same idea was being used in our structure with us hoping it would act similarly if we constructed a strong enough base.
The next part of the task was to create a doorway through the structure without it collapsing. At this stage the building was not feeling as strong as we would have hoped due to unevenness, lack of interlocking corners and so forth. With all that in my we were surprised when the door way was able to be created and the structure withstood it. Looking back at it through the use of a load path diagram (see image (g)) I was able to see how by having the bonded brick formation, it enabled the load path to be spread out and be distributed to the surrounding blocks, allowing the structure to stabilise even with the missing blocks.
(g)
2 (d)
(f)
(h)
Week 1 Studio After the doorway was completed we faced another problem of how were we going to construct a roof. Initially we kept building up to gather height but as time was cut short the decision was made to gradually bring the blocks closer together as we built up, thus gathering height and a roof. Before we knew it we constructed a dome like roof over the rectangular structure.
Not only is the cylinder/dome form good for flexibility (with what you can build) but also good for a better distribution of weight through load paths. The reason why my group’s structure failed after the first throw of a hard, weighted block though the side and the cylinder structures succeeded was due to the structure being all interlocked together, leaving no corners to fault, collapse, or strain. As shown in the two sketches below- the cylinder/dome re-adjusts and continues to distribute the load weight around the structure. Whereas, the rectangle form would end up buckling at the corners as when several holes are made the load paths would direct out to the corners and down placing pressure on the corners (if corners aren’t stable will result in collapse).
Another group even managed to take out roughly ¼ of their whole structures base with it still standing and supporting a decent weighted applied load (see image below).
After the time was up we went around to each group testing whether it could withstand a doorway to be created and whether it could further stand a weighted block to be thrown through it. My group’s structure failed after one throw of the weighted block whereas the cylinder/dome structure withstood 3-4 throws (see image to the right).
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Glossary Compression:
Tension
References Architecture 365. (2009, November, 6). Louis h Sullivan: Auditorium Building. Retrieved from http://dustingoffron.wordpress.com/2009/11/06/auditorium-building/ Auditorium Theatre of Roosevelt University. (2013). Architecture: Exterior. Retrieved from http://www.auditoriumtheatre.org/pages/home/education/chicagoslandmark-stage/art-architecture/architecture.php Ching, F. D.K. (2008). Building Construction illustrated. Hoboken, NJ: John Wiley & Sons, Inc. Pp. 2.08-2.012
Raft foundation: ‘Raft foundation is a thick concrete slab reinforced with steel which covers the entire contact area of the structure like a thick floor,� (Foundation, Concrete and Earthquake Engineering, 2013) Isotropic: Identical in all directions; invariant with respect to direction (The Free Dictionary, 2014) Anisotropic: Having properties that differ according to the direction of measure ment (The Free Dictionary, 2014)
Foundation, Concrete and Earthquake Engineering. (2013). What is Raft Foundation? Difference between Raft Foundations and Mat Foundation. Retrieved from http://civil-enggworld.blogspot.com.au/2012/06/what-is-raft-foundationdifference.html Newton, C. (2014, March 5). W01 m1 Introduction to Materials. Retrieved from https://www.youtube.com/watch?v=s4CJ8o_lJbg&feature=youtu.be The Free Dictionary. (2014). Anisotropic. Retrieved from http://www.thefreedictionary.com/anisotropic The Free Dictionary. (2014). Isotropic. Retrieved from http://www.thefreedictionary.com/isotropic 4