Sub-Systems Design Review

1. Sub-Systems Design Review P14416 Concrete Arborloo Base October 29, 2013

2. Team Intro

3. Agenda • Background • Functional Decomposition/Architecture • Updated Customer Requirements • Subsystems • Geometry • Composition • Compression Test Results • Features • Cost/Trade-off Analysis • Engineering Requirements • Project Management Updates

4. Arborloo • A latrine-like sanitation device designed to function over a small pit and to be moved to a new pit when filled • Utilize compost by planting tree in used pit • Purpose to provide affordable sanitation in poor, underdeveloped areas • Originally designed for use in Zimbabwe (Peter Morgan)

5. Functional Decomposition

6. Functional Architecture

7. Meeting with FranciusEstimable (Johnny) Weight Price: ~25 USD = 1100 HTG Type of Cement is still unknown Prefers a DIY kit to educate locals Design should be simple

8. Updated Customer Requirements 2) Simpler the better 2) Weight 1) Cost • 25 dollars • Make it available to all Haitians coming from different economic states • Easy to make • Simple mold • Limited materials/ ingredients • Make it transportable through all environments • Can be moved by 1-2 people comfortably

9. Meeting with Manitou • Self consolidating Concrete • Self Leveling • Higher Slump • No Vibration • Chemical Needed (Water Reducer) • More Efficient Mix Ratio • More Aggregate • Less Cement • Specific Gravities • Finishing Tools • Use of Fibers

10. Geometry • Shape • Thickness • Feasibility of Molds

11. Theoretical Analysis Θ b: width into the board σcomp= σflex= Maximum allowable flexural and compressive strength for each mold design: Assume square slab To make up for the lack of stress concentrations due to the hole: Factor of Safety of 3

12. Theoretical Graph

13. Feasibility of Molds • Wood • Plastic sheets (release agent) • Reusable • Not as precise • Metal • Plastic • Plastic injection methods • Foam • Expensive (concrete canoe~$800) • Very accurate • Trying to figure out the release agent

14. Composition • Aggregates • Bind properly • Provide strength • Reduce cost • Cement Replacements

15. Mixtures • 6 different mixtures (each contained cement, course aggregates, fine aggregates, and water) • Cement (ternary mix) • Portland, slag, fly ash (improves strength, workability, and requires less water) • Aggregates (all mixtures contained sand) • Course • Coconut shells • Rubber • Limestone • Fine • Sand • Plastic Beads • Styrofoam

16. Why? • Slag and fly ash improve strength of concrete when combined with Portland • Aggregates can be found in Haiti • Coconut shells • considered trash/ in abundance • Rubber • Need to figure out a way to grind up tires • Limestone/Sand • In abundance in Haiti • Plastic Beads/Styrofoam • Could grind up plastic water bottles

17. Cylinder Testing Procedure • Slump test: General idea on mold capability as well as the proper amount of water • After 7 days/28 days of curing • ASTM C39: radius= 4” height= 8” Cylinder is loaded axially. Determines maximum compressive strength (psi)

18. Test Mixtures (lbs.) *weight measured before curing

19. Cylinder Plan 70% Strength at 7 days 28 day Accepted Standard Fibers add mild Compression Strength Limestone/Rubber/ Coconut/Shells/Sand/Stryofoam/Plastic

20. Results from 7 Day Cylinders

21. Mix performance

22. Improvements Moving Forward • Add more aggregates • Used too much cement in first round of testing • Will reduce weight • Make more viscous (less water) • Styrofoam floated to the top of cylinders • Use Glenium • Use of finer aggregates • Sand is more dense than concrete • Higher strength with less voids

23. Features • Modular upgrades for additional cost • Prepare basic design to allow for add-ins • Handles • Textures • Shelter connection points

24. Transportability $5.98 All require holes and screws $2.80 $4.12 $0.48 • Handles • Wheels • Rope Attachments • Terrain is too rough for wheels • Anchor bolts require $ and drill • Mold holes in sides for handles/hooks • Can this be done? • Multi-functional attributes  simplicity

25. Shelter Interface • Grooves? • Sheet metal connection • Small size? • Also reduces material and weight • Depends on ground hole • Holes? • Consistent with transportability features • Pole connection

26. Odor/Pest Reduction • Cheap, simple cover • What can be reused? • Simple hinge? • Additional holes for toilet seat cover? • Recommendation for household materials to use • Five gallon bucket

27. How to make it visually appealing and simple at the same time:

28. Material Costs *Reflects Cost in Haiti

29. Fly Ash/Slag? • Need to evaluate cost/strength trade-off • Fly ash and slag are not produced in Haiti • Shipping costs are unknown • Currently testing mixes with and without flyash and slag

30. Cost Breakdown

31. Summary of Results

32. Engineering Requirements • Purchase Cost • Plastic expensive • Ranges from $12-$40 • Target <$25 • Load it can support • Compression Results • Only 70% strength • Ranges from 1500 psi to 4600 psi • Target >2500 psi • Ground Hole size  Over design • Weight • Average weight per/cylinder = 6.832 lbs. • Per/arborloo= 190.36 lbs.

33. Project Schedule: Past/Current

34. Project Schedule: Future

35. Budget Tracker

36. Updated Risk Assessment

37. Moving Forward • Refining concrete mixtures • Aggregates for low cost compressive strength • Flexural testing • Mold for test block • Finalize reinforcements • Cost estimates • Availability in Haiti • Shipping costs • Finalizing features • Continue to assess feasibility • Divide team between mold and mixtures