Team Vision for Detailed Design PhaseDuring this phase the team:
- Decided on a final tile design shape of "W" shape
- Ran simulations on the tile in Creo, determine the batten spacing of the tile and how the tiles would be assemble and attached on the house.
- For testing the team, the new created new molds for testing and conduct test using different variations. The variations included the amount of biochar, the size of biochar, type and amount of plastic. The results can be seen below.
- The team determine that the DOE factors would be amount of plastic, amount of biochar, and amount of cement.
- Lastly the team came up with testing procedures to be conduct on the final tile design
Final Design Choice, Modeling and Simulations
Final Tile DesignAfter careful consideration, we decided on the a modified version of the W-tile. The research that we did online did not reveal any better choice between the two, but we chose the W-tile because:
- Compared to the S-tile, the hole placement on the W-tile is more symmetric.
- The W-tile has a milder radius compared to the S-tile, which reduces the chances of cracking on the curves.
- The W-tile has flats on the bottom surfaces so that it will have a better surface to sit on, compared to the S-tile which only has curves on the bottom.
- Given the shape of the W-tile, there are more options available for overlap adjustment.
Here are some pictures of the tile as designed in CREO:
SimulationOnce we decided on a final tile design we decided to run a simulation on it where the only loads were gravity as well as a 200 lb load applied on top of the curve of the tile.
Results from the simulation done on the final tile design with a 200 lb force applied to the top of the tile
Batten SpacingWe also decided on some dimensions and designs for batten spacing on the roof as shown in the pictures:
House AssemblyWe then modeled a basic house with a roof that uses the final tile design plus a draft of curved tile at the top of the roof.
Tile OverlapHere are a couple of pictures showing how the tiles overlap:
Attachment MethodOne of the things not shown on the models is the attachment system to be used for the tiles. We decided to try on the Tyle-Tye system provided by Storm-Lock and produced a few pictures to see how it would work:
Concrete TestingFor this phase we conducted a lot of concrete testing on mixes that we made. The next few pictures will take you through the journey that we went through in the past few weeks:
Testing Observations'The biochar particles appear smaller in cured concrete than before mixing'
- Possible abrasion during mixing?
- React with water to shrink?
'Plastic decreases workability of concrete'
- Demands more water for same workability
'Most designed mixes required additional water to achieve desired workability'
- By adding water as needed, we can reduce the need to vary water experimentally
'Saturated biochar required more water to achieve same workability as unsaturated'
Eliminating % Water From Mix Design
- Water is documented to have a inverse relationship with strength
- We observed similar results
- We will not include water as a factor, the mixes that are too dry to mold with are useless to us
- We will carefully add minimum water to achieve desired workability
Stress vs Strain Relationship
Specimen Peak Load Test Results
Plastic bottle fibers offer optimistic results
- Decreasing weight of samples
- Adding strength after break, adding a safety factor
- How do we optimize the use of plastic
Particle size showed decreased weight and increased strength
- Hardwood biochar lacks pozzolanic properties (different biochar?)
- Larger particle may act like air bubble
Biochar and cement seems to compete for water
- Investigating more cement in the mix might offer better strength
- Reduce the amount of water absorbed by the biochar
Experiment Factors and Levels
- Amount of plastic bottle fiber
- Low: 0.5%
- High: 1.0%
- Amount of Biochar
- Low: 5%
- Medium: 10%
- High: 15%
- Amount of Cement
- Low: 25%
- High: 35%
Given the number of factors and levels we need...
- 3 days to complete 1 full experiment
- 6 mixes of 3 samples each day, with drying day between
- 2 weeks to cure before testing
This allows us to assess our results within 3 weeks and either…
- Replicate the design
- Redesign and run another experiment
Risk AssessmentWe updated a few risks for this phase, which are highlighted in yellow in the table shown:
Design Review MaterialsDetailed Design Presentation presented on 6th December 2016.
Here is the link to the video shown during the review: https://www.youtube.com/watch?v=gInN22guhG8
This video demonstrates how to set up the concrete on a vibrating table, then sliding it off the table and onto a mold to make a tile.
Plans for next phase
Weeks 1 to 7
- Complete DOE
- 3 Point Load Test
- Decided on the final mix
- Construct Mold from CNC Machine
- Model tile with clay
- Manufacture Mold and Device
- Attachment method
- Construct Top Tile
Weeks 8 to 15
Complete Test on Tile with final mix
- Hole in Concrete Testing
- Max. Gap Size
- Leak Test
- Saturated Drip
- Test Battens
- Heat Test
- Loudness in rain
- Lift test