Week 1 journal – constructing environments

Week 1 Journal – Constructing Environments

This week was basically an introductory week to Constructing Environments so the lecture was telling us about the expectations of the subject and introducing some main ideas.

During the tutorial we did an exercise in groups where we were required to build a tower as high as we could out of wooden blocks, however we were required to have an opening for something to fit through, as well as having a roof over the top. The idea was that we were to make a structure that worked well under compression and was stable under weight. Unfortunately my group experienced a little trouble with this task, but we have since learnt the proper way to go about this situation. We started building our tower by creating the arch, the idea was the we would slowly place each block further inwards than the last so that eventually both sides of the tower would join to form an arch. We however had to make sure that there was enough weight holding down the overhanging blocks to ensure they did not collapse inwards.

This is one of the initial stages of the arch, you can see the blocks slowly coming into a point, and the blocks are stacked like bricks (on top of each crack/join) to ensure stability.

As can be seen from the image adjacent to the text, the arch is almost at a point, w e however found that if we were to join the top of the arch, the compression forces that the blocks would have put o n the arch, w ould have caused it to collapse in on itself, this is most likely d ue to each side of the arch being built too far away from one another creating too wide of a gap. So we decided to build around the arch to make the rest of the tower.

Unfortunately our tower didn’t get to a great height or even have a roof, this was because the area inside the tower was too large to create a roof and the walls of the tower itself were far too unstable to even attempt to hold up a roof. Below it can be seen our final attempt at the tower.

As can be seen in the left image above we tried to taper in the top of the structure to create a roof, however it became too unstable and almost collapsed. To the right it can be seen how we supported the arch to keep it from collapsing inwards because of the weight of the blocks. W e created a column that opposed the downwards force of the blocks of the middle of the arch and in turn stopped any possible downward movement of the blocks.

In the tutorial I learnt that when making beams across the top of the tower (ours was too structurally unstable to attempt this) the beam wants to deflect and buckle, or in other words, the top part is coming together in compression, and the bottom part is stretching apart which is tension. The shape it flexes is concave. The beams are not able to deal with compression, because the bottom of the beam is under tension. When making a beam, putting the rubber bands at the bottom of the beam will help take all the tension away. The same is for reinforced concrete beams; they have steel in the bottom as steel is high in tensile strength. The other force or one of the other forces in action with beams is shear force, which has to be overcome in order for the beams to work properly.

In order for our tower to work better, be more stable, and be able to handle compression more, we had to fix multiple things. Firstly the area inside the tower was too large so made the walls flimsy. Secondly, as displayed in some of the other towers, we should have placed the blocks not only flat but on their edges as well to increase the stability. The other issue as mentioned before is that the arch was not constructed properly as it was far too wide and could not withstand the pressure of the rest of the blocks. Perhaps a better way to build the opening would have been to build straight up, and used the beam idea from earlier to connect each side and form a closed over opening.

Below is one of the towers that worked. It was stable and able to withstand great amounts of weight because it spaced out the blocks giving the structure strength.

It was also not too wide in the center and the center of gravity was in the center.

Thermal mass is a term which is used to describe a particular materials ability to store heat. Materials with thermal mass are able to absorb heat, then store it, then eventually release the heat again. A building material can be either heavy weight in which it has a high thermal mass and can store lots of heat, or lightweight, in which it has a low thermal mass and less of an ability to store heat. For example, a house with materials of high thermal mass in summer absorbs heat during the day, meaning that the inside of the house does not heat up as easily, or the temperature is more regulated.

For the next tutorial we have been given the task of building a tower as high as possible with thin strips of balsa wood, which is very light and easily breakable.

Below is just an idea that my group had when we met up to discuss this activity and cut the wood. We may have to add some more supports but hope that it works and is stable.

The reading this week and interactive structures didn’t really help in terms of learning about constructing, however it did provide an introduction to what is still to come.

References:

Unknown. n.d.. Sustainable Energy Info. [e-­‐book] Victoria: Sustainability Victoria.

Available through: Sustainability Victoria http://www.sustainability.vic.gov.au/resources/documents/thermal_mass.pdf [Accessed: 6th August 2013].

Constructing Environments Tutorial