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Answer to Activity 1
Straw-Reinforced Ice Beams
Method:
Step 1.
Adding water until the beams broke (as shown in Fig 1) tested plain ice beams. The water quantity used was measured and recorded.
Fig 1. Setting up the Plain Ice beam ready for testing
Step 2.
The Ice/Straw Composite Beam was set up ready for testing (see Fig 2). Again the results were recorded.
Fig 2. Setting up the Ice/Straw composite beam ready for testing
Results:
| Beam | Water Quantity | Load |
|---|---|---|
| Ice 1 | 4.7 litres | 4.7 kg |
| Ice 2 | 4.8 litres | 4.8 kg |
| Straw/Ice Composite 1 | 9.7 litres | 9.7 kg |
| Straw/Ice Composite 2 | 8.8 litres | 8.8 kg |
Observation:
The broken Ice/Straw composite showed the nature of the forces in a bend test in that the tensile forces in the underside of the beam can be easily identified in Fig 3.
Fig 3. The broken ice/straw composite
Conclusion:
The average load that could be applied to the ice beam was 4.75kg while the ice/straw composite was able to handle an average load of 9.2kg. The increase in bend strength clearly demonstrates how the two materials that make up the composite complement each other’s mechanical properties. The ice is strong in compression whilst the straw provides an increased tensile strength.
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