Smart Structures
Design Overview:
Construction technology is a field that has seen very slow innovation in the recent decades. Today, demand for housing goes up as their price goes up. There is a need to improve construction technologies to fill that gap in the housing industry. A viable solution is to 3D print concrete which allows for:
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faster production
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Reduced material consumption and waste
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improved design capabilities of construction
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improved logistics and operation
The team must design and provide a proof of concept for a solution to 3D print different blends of concrete, making the process more environmentally friendly and more affordable.
1. Market Research
The team started looking at the current industry. Although this is a very new field, we found several private companies which have developed their own concrete 3D printers. We tried to get in contact with them, but had no success. We also reached out to researchers affiliated with Universities and Research Institutes.
At first the team also focused on a specific blend of concrete called aircrete, which is the mix of traditional concrete with a foaming agent. We decided to look at this alternative due to the fact that it uses less concrete, leading to cheaper production cost and decreased waste of material.The team researched online about the process of making aircrete and the existing concrete 3D printers. We found that most people make the foam and mix it into concrete by hand. A homemade machine designed to make the aircrete was found being sold by an inventor in Oregon. Besides other homemade machine tutorials and hand making processes for the foam, not much else was found on how to produce it.
Opportunity Areas
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All current machines use premixed concrete mixes
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Most machines use pumps to move concrete mix from mixing tank to printer head, which is very expensive and has a high risk of clogging
2. Preliminary Design Tools
Function tree
The function tree defines, in chronological order, the tasks and subtasks the machine must follow.
Customer needs and Engineering Requirements
The customer needs and engineering requirements chart shows several features the machine should have and how important each one of those are. This was done to define which features should be focused on.
Having the ability to mix concrete/aircrete was the feature with the highest importance, followed by being able to integrate with existing 3D printing technology and having a long lifecycle.
Engineering Requirements
The engineering requirements chart displays concrete values for the design considerations presented.
3. Ideation
Sketching
CAD
4. Testing
The team made several samples of concrete and Aircrete by hand for a better understanding of material behaviors and properties.
CAD parts were 3D printed and, using these parts, the team made more samples of concrete and aircrete. Those samples were tested and compared with the handmade ones.
5. Final Mixing Design
We arrived at the right ratio of water to cement to sand that fit our machine.
Finally, we had a machine that could extrude and mix concrete at the same time autonomously
The image above shows the whole layout of what the prototype of our machine would look like.
The video to the right simulates our sorting mechanism (on the top), our mixing and extruding mechanism (on the bottom), mixing cement (in white), and sand ( in yellow). The other two funnels could have additives and be programed to add the right ratios of material needed.
6. Next Steps
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Develop more automated functions to create an easier experience for the user
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Develop a nozzle system for better and more automated extrusion
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Integrate existing 3D printing technology into our system
