Integrated System Build & Test
Table of Contents
Team Vision for Integrated System Build & Test Phase
In this phase:
- Finalized the DOE and determined the mix
- Added the attachment “nub” to the manufacturing device
- Performed an initial leak test on the test piece tiles and on a full size tile
- Drafted plans for the Test Rig
- Started a preliminary cost analysis
- Compared pumice rock vs. biochar
Design of ExperimentThe JMP output seen below shows the results of our completed design of experiment with two replications. You will notice two sections, the strength results and the weight results. For each set of results there are four accompanying plots showing how each factor affects strength and weight for respective sections.
Based on the graphs, the strength of the concrete increases as the amount of biochar, cement and water in the concrete mix increases. Although we only found a 90% statistical significance with biochar and cement.
From a weight perspective, we only found biochar to have 90% statistical significance. By increasing the amount of biochar in the mix we were able to consistently reduce the weight of the concrete.
Based on these findings we decided on our final mix to consist of 35% concrete, 20% Biochar, and 45% Sand with .423 lbs of plastic bottle fiber per cubic foot.
Attachment Method UpdateIn this phase, we made a tile using the full prototype of our manufacturing device. We discovered that the first nub addition accessory had too small a footprint to reliably adhere to the main tile. The design was intended to be modular so these kind of changes can be easily made. The next nub iteration will have a wider footprint for better adhesion.
Preliminary Leak TestIn this phase we were able to do some preliminary Leak Testing using test pieces that were shorter than a full tile but just as wide. We were also able to do a Leak Test on the tiles made from the last design review.
Test RigWe made plans on making a test rig that has 9 tiles and 4 battens. This rig will be used to run our tests, and will also be used for the Imagine RIT exhibit.
Preliminary Cost AnalysisSpreadsheet for the Cost Analysis.
Pumice Rock vs. BiocharIn this phase we did some research comparing Pumice Rock with Biochar.
Pumice Rock is an extremely porous igneous rock formed during volcanic eruptions. The material can be used in several aspects like lightweight concrete or as an abrasive for a variety of products. The material generally have high enough porosities that they can float in water until it becomes filled with water. To determine whether pumice rock or biochar would be better suited for this application, we are researching the properties of the two substances. Though the resources for our project does not allow testing of pumice rock in concrete, the goal is to provide a comparison that would suggest if one material would be more useful to Nicaraguan roof tiles than the other. More research has been conducted using pumice stone in concrete compared to biochar. Pumice stone is known to have benefited the insulation properties of concrete, while research is still being done to determine the effects of biochar. Biochar is often more brittle and has less mechanical strength by nature than pumice rock, which causes areas of the biochar-concrete to be weaker.
Plans for next phase
- Continue to work on paper and Imagine RIT poster
- Continue testing of roof tiles via test procedures
- Make a vacuum formed mold
- Refine attachment method on manufacturing device
- Work on three test rigs, one 'waterproof' rig for the water test inside a cooling tower, a rig made out of wood with metal battens for other tests for our tiles, and a rig with wood supports for the zinc roof to show on Imagine RIT.