Sub-Systems Design Review

Transcription

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

2 Team Intro Member Victoria Snell (ISE) Evan Burley (ME) Joe Omilanowicz (ME) Mac Keehfus (ME) Anthony Deleo (ISE) Role Project Manager Engineer Engineer Engineer Engineer

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

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 b: width into the board σ comp = F sin (theta) σ flex = F cos (theta) d b (3 L L i )/(b d 2 ) Θ 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 1200 Flexural Strength vs Theta Shear Stress 70 Compressive Stress vs Theta Compressive Stress Strength (psi) 600 Stress (psi) Theta (Degrees) Theta (Degrees)

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.) Units (lbs) Mix 1 Mix 2 Mix 3 Mix 4 Mix 5 Mix 6 Mix 7 Mix 8 Mix 9 Cement Slag X 1.05 Flyash X 0.82 Sand Rubber 1.20 X X 1.20 X X 2.21 X X Styrofoam X X 0.01 X 0.04 X X Plastic X X X 0.68 X X X Coconut X X X X X Limestone X X X X X X X Water Glenium X X X X X X 10mL 8mL 8mL Weight/cyl * 7.16* 7.32* *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 Max Compressive Force For Mix (Kips) Trial (7 days) (28) Recorded 3 Max Compressive Strength (psi) Trial (7 days) (28) Area of Test cylinder= A= π*r 2 σ=f[lbf]/a[in 2 ] Mix Tensile Strength (psi, assume 15% compression) Trial (7 days) (28)

21 lb/ft^3 Compressive Stress (psi) Mix performance Mixture lb/ft^ Mixture Compressive Strength Mix 1 Mix 2 Mix 3 Mix 4 Mix 5 Mix 6 Mix 1 Mix 2 Mix 3 Mix 4 Mix 5 Mix 6

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 Handles Wheels Rope Attachments All require holes and screws 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 $4.12 $2.80 $0.48

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

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 Materials Cost Weight (lb) Cost/lb Rubber Mulch $ $ 0.55 Coconut* $ - - $ - Limestone $ $ 0.01 Sand* $ - - $ - Styrofoam $ $ 7.50 Plastic $ $ 4.00 Cement* $ $ 0.07 Slag $ $ 0.05 Fly Ash $ $ 0.04 *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 Cement Fly Ash Slag Rubber Coconut Shells Weight Cost/lb Weight Cost Weight Cost Weight Cost Weight Cost 1 Cylinder 4.2 $ $ $ $ $ - Arborloo $ $ $ $ $ - Limestone Sand Styrofoam Plastic Pellets Weight Cost Weight Cost Weight Cost Weight Cost 1 Cylinder 0.6 $ $ $ $ 0.92 Arborloo 16.6 $ $ $ $ 25.84

31 Summary of Results PM Arborloo Cylinder Strength (psi) Ranking Score Mixtures Coarse Ag Fine Ag Total Cost Weight Compressive Tensile* Total Cost Weight Strength Total Mix 1 Rubber Styrofoam $ Mix 2 Coconut Styrofoam $ Mix 3 Coconut Plastic $ Mix 4 Rubber Plastic $ Mix 5 Limestone Styrofoam $ Mix 6 Limestone Plastic $ * Assume 20% of compression strength

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 = lbs. Per/arborloo= lbs.

33 Project Schedule: Past/Current

34 Project Schedule: Future

35 Budget Tracker Item Store Price 94 lb Portland Cement Home Depot $ " PVC Fencing Home Depot $ "x.25" Round Steel Rod Home Depot $9.26 Bird Netting Home Depot $ cu ft Rubber Mulch Home Depot $5.97 Plastic Sheeting Home Depot $10.98 Hardware Cloth Home Depot $9.22 Chicken Wire Home Depot $7.97 Bean Bag Filler Bed Bath and Beyond $14.99 Cement Mixer Lowes $8.54 Platic Beads Jo-Ann Fabrics $ gallon Bags Target $8.18 Styrofoam Michael's $ x8 Test Cylinders Forney LP $57.06 Total: $191.06

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