Sub-Systems Design Review
description
Transcript of Sub-Systems Design Review
Sub-Systems Design ReviewP14416
Concrete Arborloo Base
October 29, 2013
Team Intro
Member RoleVictoria Snell (ISE) Project ManagerEvan Burley (ME) EngineerJoe Omilanowicz (ME) EngineerMac Keehfus (ME) EngineerAnthony Deleo (ISE) Engineer
Agenda• Background• Functional Decomposition/Architecture• Updated Customer Requirements• Subsystems
– Geometry– Composition
• Compression Test Results– Features
• Cost/Trade-off Analysis• Engineering Requirements• Project Management Updates
• 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)
Arborloo
Functional Decomposition
Functional Architecture
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
Updated Customer Requirements
2) Weight
• 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
1) Cost 2) Simpler the better
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
Geometry
• Shape• Thickness• Feasibility of
Molds
Theoretical Analysis• 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
Θ
b: width into the board σcomp=σflex=
Theoretical Graph
0 50 1000
200
400
600
800
1000
1200
Theta (Degrees)
Stre
ngth
(psi
)Flexural Strength vs Theta
Shear Stress
0 50 1000
10
20
30
40
50
60
70
Theta (Degrees)
Stre
ss (p
si)
Compressive Stress vs Theta
Compressive Stress
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
Composition
• Aggregates• Bind properly• Provide strength• Reduce cost
• Cement Replacements
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
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
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)
Units (lbs) Mix 1 Mix 2 Mix 3 Mix 4 Mix 5 Mix 6 Mix 7 Mix 8 Mix 9
Cement 12.49 12.49 12.49 12.49 12.49 12.49 2.35 4.83 2.96
Slag 5.85 5.85 5.85 5.85 5.85 5.85 0.83 X 1.05
Flyash 4.82 4.82 4.82 4.82 4.82 4.82 0.65 X 0.82
Sand 1.50 1.50 1.50 1.50 1.50 1.50 6.95 8.87 8.87
Rubber 1.20 X X 1.20 X X 2.21 X X
Styrofoam 0.01 0.01 X X 0.01 X 0.04 X X
Plastic X X 0.68 0.68 X 0.68 X X X
Coconut X 1.20 1.20 X X X X 4.14 4.14
Limestone X X X X 1.77 1.77 X X X
Water 7.75 7.75 8.26 7.5 8 8.26 1.72 2.18 2.18
Glenium X X X X X X 10mL 8mL 8mL
Weight/cyl 6.45 6.77 6.70 6.73 6.88 7.08 4.53* 7.16* 7.32*
*weight measured before curing
Test Mixtures (lbs.)
Cylinder Plan• 70% Strength at 7 days• 28 day Accepted
Standard• Fibers add mild
Compression Strength• Limestone/Rubber/
Coconut/Shells/Sand/Stryofoam/Plastic
Results from 7 Day Cylinders
Trial 1 2 3 4 5 61 (7 days) 22.64 37.67 34.67 21.35 47.07 58.58
2 (28)3
Trial 1 2 3 4 5 61 (7 days) 1801.634 2997.683 2758.95 1698.98 3745.71 4661.65
2 (28) 0 0 0 0 0 03 0 0 0 0 0 0
Trial 1 2 3 4 5 61 (7 days) 270.24509 449.6525 413.843 254.847 561.857 699.247
2 (28) 0 0 0 0 0 03 0 0 0 0 0 0
Max Compressive Force For Mix (Kips)
Max Compressive Strength (psi)
Recorded
Mix Tensile Strength (psi, assume 15% compression)
Area of Test cylinder= 12.56637A= π*r2 σ=F[lbf]/A[in2]
Mix performance
104
106
108
110
112
114
116
118
120
122
124
Mixture lb/ft^3
Mix 1 Mix 2 Mix 3 Mix 4 Mix 5 Mix 6
lb/ft
^3
0
500
1000
1500
2000
2500
3000
3500
4000
4500
5000Mixture Compressive Strength
Mix 1 Mix 2 Mix 3 Mix 4 Mix 5 Mix 6
Com
pres
sive
Stre
ss (p
si)
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
Features• Modular upgrades for additional cost• Prepare basic design to allow for add-ins
• Handles• Textures• Shelter connection points
Transportability
• 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
$5.98
$2.80
$0.48
All require holes and
screws
$4.12
Shelter Interface• Holes?
– Consistent with transportability features– Pole connection
• Grooves?– Sheet metal
connection• Small size?
• Also reduces material and weight
• Depends on ground hole
Odor/Pest Reduction• Cheap, simple cover• What can be reused?• Simple hinge?
• Additional holes for toilet seat cover?
• Recommendation for household materials to use– Five gallon bucket
How to make it visually appealing and simple at the same time:
Material CostsMaterials Cost Weight (lb) Cost/lb
Rubber Mulch 10.98$ 19.8 0.55$ Coconut* -$ - -$ Limestone 10.00$ 2000 0.01$ Sand* -$ - -$ Styrofoam 14.99$ 2 7.50$ Plastic 7.99$ 2 4.00$ Cement* 6.28$ 94 0.07$ Slag 90.00$ 2000 0.05$ Fly Ash 70.00$ 2000 0.04$
*Reflects Cost in Haiti
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
Cost Breakdown
Weight Cost/lb Weight Cost Weight Cost Weight Cost Weight Cost1 Cylinder 4.2 0.28$ 1.6 0.06$ 2.0 0.09$ 0.2 0.11$ 0.2 -$ Arborloo 117.0 7.82$ 45.3 1.58$ 54.8 2.47$ 5.6 3.12$ 5.6 -$
Weight Cost Weight Cost Weight Cost Weight Cost1 Cylinder 0.6 0.00$ 0.5 -$ 0.003 0.02$ 0.2 0.92$ Arborloo 16.6 0.08$ 14.1 -$ 0.079 0.59$ 6.5 25.84$
Sand StyrofoamLimestone
Cement Fly Ash Slag Rubber Coconut Shells
Plastic Pellets
Summary of Results
ScoreMixtures Coarse Ag Fine Ag Total Cost Weight Compressive Tensile* Total Cost Weight Strength TotalMix 1 Rubber Styrofoam 15.58$ 181.41 1801.63 360.33 4 6 2 12Mix 2 Coconut Styrofoam 12.46$ 190.41 2997.68 599.54 6 4 4 14Mix 3 Coconut Plastic 37.71$ 188.44 2758.95 551.79 3 5 3 11Mix 4 Rubber Plastic 40.83$ 189.28 1698.98 339.80 1 3 1 5Mix 5 Limestone Styrofoam 12.54$ 193.50 3745.71 749.14 5 2 5 12Mix 6 Limestone Plastic 37.80$ 199.13 4661.65 932.33 2 1 6 9
Cylinder Strength (psi) Ranking
* Assume 20% of compression strength
PM Arborloo
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.
Project Schedule: Past/Current
Project Schedule: Future
Budget TrackerItem Store Price
94 lb Portland Cement Home Depot $10.47
40" PVC Fencing Home Depot $9.97
48"x.25" Round Steel Rod Home Depot $9.26
Bird Netting Home Depot $14.47
.8 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 $14.99Cement Mixer Lowes $8.54Platic Beads Jo-Ann Fabrics $14.992 gallon Bags Target $8.18
Styrofoam Michael's $8.994”x8” Test Cylinders Forney LP $57.06
Total: $191.06
Updated Risk Assessment
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