Week 4 Journal When we got to the stage of securing the pine wood blocks to the planks with screws however, we found that the screws split the wooden blocks in two, as the screw was inserted straight along the grain of the wood, compromising its structural integrity and causing it to break.
In week 4, we participated in a workshop activity where we were required to build a bridge which would have a span of one metre. We were given two pine wood planks and two thin plywood sheets. Our group devised a design where we would put several pine wood blocks in between two planks at measured intervals, and then sandwich this structure between the two plywood sheets. The entire structure would be held together with nails. We intended for the structure to sit vertically, with the pine wood plank facing upwards. It was designed in this way so that any downward force applied would be unloaded in the gaps between the two pine wood planks.
Constructing Environments Brian Siu (635900)
Week 4 Journal Due to the wooden blocks spliting in half, we decided to halve the thickness of all the wooden blocks, and used the improvised blocks the same way as we originally planned. Although the final completed structure was half the thickness we originally intended, it still more or less followed our original design.
During the actual test of putting load onto the structure, our structure managed to hold approximately 420 kilograms before it broke. In assessing the damage, we found that the plywood sheets on the sides warped and snapped under pressure, especially at the parts which weren’t nailed to the pine wood planks. We also found that the underside of the pine wood plank fractured. As the underside relies on tension, the downward force eventually pulled it apart, creating the fracture on the underside of the plank. It may have helped if we placed a wooden block under that area to cushion and support the plank.
Constructing Environments Brian Siu (635900)