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Ska’ana

University of Washington

ASCE Concrete Canoe

Design Paper 2015

National Competition

Clemson, South Carolina

June 20-22, 2015

2014-2015

Ska’ana | i

Table of Contents Executive Summary ...................................................................................................... ii

Project Management ..................................................................................................... 1

Organization Chart ........................................................................................................ 2

Hull Design ................................................................................................................... 3

Structural Analysis ........................................................................................................ 4

Testing and Development .......................................................................................... 5-7

Construction ............................................................................................................... 8-9

Project Schedule.......................................................................................................... 10

Design Drawing .......................................................................................................... 11

List of Figures

Figure 1: 2015 Program Innovation. ............................................................................. ii

Figure 2: Critical Path. .................................................................................................. 1

Figure 3: Project Work-hours by Category. .................................................................. 1

Figure 4: Project Revenue vs. Expenses. ...................................................................... 1

Figure 5: Hull Profile of Ska’ana.................................................................................. 3

Figure 6: Canoe-Beam Moment Demands. .................................................................. 4

Figure 7: Bending Direction of Floor. .......................................................................... 4

Figure 8: Local Floor Moment Demands...................................................................... 4

Figure 9: Cross Section of Three Layer Design............................................................ 5

Figure 10: Selection of Optimal Structural Concrete. .................................................. 5

Figure 11: Selection of Lightweight Thickness. ........................................................... 6

Figure 12: Cylinder, Cubes, and Wire. ......................................................................... 6

Figure 13: Placing Assessment. .................................................................................... 7

Figure 14: Composite Panel Testing. ............................................................................ 7

Figure 15: Mold Fabrication Stages. ............................................................................. 8

Figure 16: Floor Layer Schematic. ............................................................................... 8

Figure 17: Reinforcing Layout...................................................................................... 8

Figure 18: Anchor and Sawn Channel. ......................................................................... 9

Figures E1-E4: Bow Damage at Regional Conference............................................... E2

List of Tables

Table 1: Ska’ana Specifications .................................................................................... ii

Table 2: Ska’ana Material Properties ........................................................................... ii

Table 3: Failure State Safety Factors ............................................................................ 4

Table 4: Comparison to Baseline Mixes ....................................................................... 5

List of Appendices

APPENDIX A: References .................................................................................... A-1-2

APPENDIX B: Mixture Proportions ..................................................................... B-1-4

APPENDIX C: Bill of Materials............................................................................... C-1 APPENDIX D: Example Structural Calculation ................................................... D-1-2

APPENDIX E: Repair Procedures Report ............................................................. E-1-2

Cover picture: “Orca” by Kim is licensed under CC BY 2.0 and can be found at https://flic.kr/p/8cR5Kg.

Executive Summary 2014-2015

Ska’ana | ii

Table 1. Ska’ana Specifications The origin of the Orca whale embodies a legend of sustainability for the native

Haida people of the Pacific Northwest. The story begins with a man who raises

two wolf pups he finds on a beach. Once grown, the wolves swim into the ocean

daily to hunt whales for food. Each day the wolves would hunt, accumulating

far too much food. The Great Above Person saw this wastefulness and punished

the wolves by creating a fog while they were hunting at sea, rendering them

unable to hunt or return to the shore. These wolves remained at sea,

transforming into the Orca whales of today. The Haida people refer to Orca

whales as “ska’ana,” or supernatural spirit.

As descendants of wolves, the Huskies related to this legend and built the 2015

team around reducing waste and learning from the past. By reflecting on the 2013 and 2014 competitions, the

2015 program set out to increase responsibility in finance, safety, sustainability, and quality assurance. The

University of Washington presents the 2015 canoe, Ska’ana, which represents the power of the Orca and the

innovation of the 2015 Huskies.

Located in Seattle, the University of Washington

Concrete Canoe Team competes in the Pacific Northwest

ASCE Student Conference. In the past three years at the

Conference level, the University of Washington placed

2nd

overall in 2012, 1st in 2013, and 1

st in 2014. At the

National Competition in 2013 and 2014, the team placed

16th

and 18th

respectively, credited to strong paddlers and

a fast canoe design. One of the highlights included the

2014 Design Paper which narrowly missed top ten by

placing 11th

and set the standard for future competitions.

The Huskies once again look to excel at the national level

with an impressive performance.

Ska’ana’s hull features a lightweight, asymmetric design

with a well-balanced rocker and redefined cross-section

geometry. Two reinforcing types are decoupled and

efficiently resist both canoe-bending and local floor

loads. The composite buildup featured in Ska’ana is

based on two structural layers sandwiching a lightweight layer for an ultra-lightweight and durable composite

structure. Tables 1 and 2 summarize Ska’ana’s basic specifications and material properties. For the first time in

recent history, the Huskies successfully integrated a lightly post-tensioned repair system to prevent tension

cracking in the canoe gunwale.

This year the Huskies aim high for the National Competition incorporating innovations across the program.

With the breakthroughs summarized in Figure 1, the Huskies proudly deliver Ska’ana, a canoe crafted with a

45% faster placing, a 55% cost reduction, and a 45% lighter weight. The Huskies look forward to a great

competition and the program’s continued success.

Table 2. Ska’ana Material Properties

Project Management Financial strategies Knowledge transfer workshops Critical Design Review Seasonal newsletter Final Product Unveiling Hosted high school students

Design Asymmetric hull design Double curvature in stern section Mold parting features in forms High range water reducer Understanding composite behavior Post-tensioned repair system

Construction Recycled 2014 ESP mold Workspace inventory Improved safety procedures Material mass flows Plastic densities per batch Curved underside of gunwales

Figure 1. 2015 Program Innovation

Project Management 2014-2015

Ska’ana | 1

Figure 2. Critical Path

O&D Meetings Mix Development Mix Selection Structural Design Critical Review Final Prep. Concrete Placing Curing Canoe Finishing Floatation Test Critical Repairs Product Unveiling Regional Conf. National Prep. Ship Equipment National Comp.

10/15/14 12/4/14 12/5/14 1/5/15 1/8/15 1/16/15 1/17/15 1/30/15 4/3/15 4/4/15 4/8/15 4/9/15 4/17/15 6/9/15 6/10/15 6/20/15

Critical Path

Construction 1,400

Project Hours 2,870hrs

Mix Design 450

Financing 370

Academics 330

Structural 250

Hull Design 280

Outreach 120

Figure 3. Project Work-hours by Category

$6,400 Regional Conf.

$1,645 Construction

$1,600 Trailer Repairs

$500 Outreach

Project Expenses $23,375

$13,230 National Comp.

Project Revenue $37,370

$8,800

$14,350

$8,550

$5,670

Personal Donations

Business Donations

Material & Services

Grants

Figure 4. Project Revenue vs. Expenses

To begin the 2015 project, Objective & Deliverable (O&D) meetings occurred in the

first weeks of class. The O&D meetings set team-wide expectations, responsibilities,

and a clear direction which allowed horizontal and autonomous operations. To secure

smooth operations, weekly lead meetings covered objectives, watch items, and

mitigation strategies. Following lead meetings, general meetings covered milestones,

resource allocation, and design discussions. The 2015 management discussed

direction and rationale throughout the design and construction of Ska’ana.

Critical milestones, emphasized in Figure 2, maintained project flow while design

and construction tasks ran in parallel chains to shorten overall project schedule. Prior

to placing, a Critical Review was held with industry experts to verify and refine

design rationale and construction sequences. To further shorten the critical path,

composite panel testing was conducted after canoe placing as a noncritical chain.

Historically, composite testing is the most material/time-intensive test; however, this

year only one as-built panel set was fabricated and tested which reduced significant

material consumption and time. Prior to placing, detailed structural analysis

was conducted to substantiate local strengths and as-built flexural test results

were as expected. One significant change to the 2015 schedule was moving

canoe placing from late-November to mid-January. Placing in January

allowed more resources for design, preparation, and a quicker strength gain

due to warmer temperatures. Because a later placing decreased canoe

finishing time, more resources were allocated to patching/sanding and an

aesthetic design which took 60% less time was selected. Despite gunwale

tension and floatation failures during the Floatation Test, no delays to the

critical path were experienced because adequate slack was introduced before

the Product Unveiling; the Unveiling milestone acted as a final net to catch

discrepancies prior to the Regional Conference. Because of the risk

mitigation and technical expertise of the 2015 team, deviations to the original

schedule did not affect the completion date. The breakdown of project work-hours is shown in Figure 3.

Financial resources were spent on competition

registration and personnel/equipment transportation. Less

than 10% of the resources went towards materials and

construction because most materials were donated.

Funding up until the Regional Conference was covered

by local business donations. After the team qualified for

the National Competition, the project budget doubled and

funding was earned through a rigorous crowdfunding

program. Additionally, grants from local organizations

were pursued throughout the project. A comparison of

project revenue and expenses is shown in Figure 4.

Safety and quality were treated as critical team-wide responsibilities. The 2015 safety program featured testing

equipment/tool training, Job Hazard Analysis Forms, workday safety orientations, and a safety equipment

station. As for quality, multiple assurances were introduced in the 2015 program. Major practices included

taking plastic densities of concrete batches for real-time feedback, providing hands-on concrete placing

trainings, and assigning experienced members as mentors and quality personnel. Maintaining a clean workspace

was a major objective for both safety and quality reasons. The 2015 safety and quality assurance procedures

were vital reasons Ska’ana was delivered at 178 pounds with astounding finishing detail and with zero injuries.

Organization Chart 2014-2015

Ska’ana | 2

List of Members

PA: Paddling AS: Aesthetics SD: Structural Design FI: Finances HD: Hull Design MD: Mix Design CO: Construction OR: Outreach TR: Transportation

Leadership Team

Nigel Lyons Project Manager Structural Design

Robert Frankel Finances

Matt Hazenberg Transportation

Kim Tsai Aesthetics

Nick Orsi Construction

Paddling

Ian Dahl Construction

James Neher Mix Design

Hull Design

Marissa Karpack Mix Design

Mark Chen Outreach

Paddling

Hull Design 2014-2015

Ska’ana | 3

The 2015 design team had a clear picture of the previous design’s performance because the same hull was

featured for two consecutive years with Undammed (2013) and The Lady (2014). The previous designs achieved

great straight-line speed due to very long and narrow hulls (2 feet wide by 21.5 feet long). However, the overall

control of the canoe was poor because the canoe easily over steered, exhibited very poor tracking capabilities,

and demonstrated sliding movements of the stern section. The poor control was attributed to the very soft stern

chine, extremely high 4 inch stern rocker, and a very low 0.5 inch bow rocker. With these features in mind, the

2015 team design intended to increase control by reducing turning capabilities while still maintaining straight-

line speed.

The design team researched basic geometric canoe performance parameters and reviewed photographs of

national ranking concrete canoes for inspiration and general hull shapes. Four initial designs were drafted by

altering The Lady based on qualitative adjustments. Two designs were eliminated based on general look and

constructability issues (too narrow of end sections). Of the two remaining designs, a final design was

quantitatively selected through a geometric analysis and comparison to the previous years. Straight-line speed

was compared by assessing wetted surface areas, entry angles, and prismatic coefficients (Sailboat, Winters).

Areas and moments of inertia of the lateral water plane were compared to evaluate turning and tracking, which

were inversely proportional. Rolling stability was assessed by the moments of inertia of the transverse water

plane about the longitudinal axis.

The top profile was changed to maintain and increase straight-line speed. The asymmetric top profile features

an increased stern curvature, a sharper bow, and a beam placed 13 inches aft. Changes to the keel were meant to

increase the control and tracking of the canoe. The canoe rocker was balanced by reducing the stern rocker from

4 to 2 inches and by increasing the bow rocker from 1 to 2 inches. Additionally, to improve the balanced control

of the canoe, the flat midsection was moved to be more centered and elongated from 86 to 129 inches. These

features can be observed in Figure 5. Cross section changes served multiple purposes including increased

buoyancy, increased tracking, a more aft steerer, and improved concrete placing and mold parting.

Because the rocker was reduced and the lateral water plane was increased, turning capabilities of the canoe were

reduced. However, redefined chines and mid sections of Ska’ana in conjunction with a veteran paddling team

will ensure competitive competition turns. As a new design, Ska’ana is fast, lightweight, and looks to dominate

the waters just as its powerful name embodies.

Figure 5. Hull Profiles of Ska’ana

Improved stern curvature Sharper bow Beam 13 inches aft

Structural Analysis 2014-2015

Ska’ana | 4

-6

-4

-2

0

2

-10 -8 -6 -4 -2 0 2 4 6 8 10

Mo

men

t (k

-in

)

Length Along Canoe (ft)

Display

Figure 6. Canoe-Beam Moment Demands

2-Male

Coed

Figure 7. Bending Direction of Floor

Transverse Axis

Longitudinal Axis

-450

-300

-150

0

150

300

0 3 6 9 12 15 18

Mo

men

t (l

bs-

in)

Width Across Floor (in)

No Paddler

Figure 8. Local Floor Moment Demands

Balanced

Leaning

Demands for canoe-beam shear/bending were determined from vertical

and rotational equilibrium between paddlers, self-weight and buoyancy.

Buoyancy along the length of the canoe was a function of mean water

draft and canoe inclination. A spreadsheet iterated draft and inclination

until vertical and rotational equilibrium were met. Internal shear/bending

was determined after support conditions were satisfied. Load cases

included 2-Male (controlling), Coed, and Display (shown in Figure 6).

Long distance transportation within a vehicle was neglected because a

uniformly supported condition was assumed. See Appendix D for a

simplified hand verification of 2-Male demands.

To analyze stresses imparted from the canoe-beam demands, the following assumptions applied: sections

remained planar after bending, proportional stress-strain relationships, and negligible reinforcing stiffness. A

spreadsheet calculated section properties, and demands were multiplied by the applicable moduli to determine

internal stresses of a given cross section (see Appendix D for programming and applicable equations). Tension

stresses were then compared to the minimum of adjusted split cylinder tests or the rupture modulus estimated

per ACI 9.5.2.3 (selected limit, see Appendix D). Shear stresses were compared with allowables based on ACI

11.1.2.1. Safety factors are shown in Table 3 for canoe-beam behavior.

Demands on the canoe floor due to local paddler/hydrostatic loads were

found by analyzing one-way bending of a panel. Floors bended about the

longitudinal canoe axis as the walls provided rigidity against bending

about the transverse direction (comparable to one-way slabs).

Additionally, local reinforcing was stiffer in the transverse direction

which transferred floor loads to the walls. Figure 7 shows the bending

behavior of the canoe floor and annotates the canoe axes. The models

were fixed at both ends and lateral loads on the walls were applied as

equivalent end moments on the panel. Load cases included the following:

a single, asymmetric point load representing a leaning paddler

(controlling), two equal point loads centered for a balanced paddler, and a

no paddler case with a uniform hydrostatic pressure. The local floor

demands are shown in Figure 8, and safety factors are presented in Table

3. Stress demands in the floors were calculated with similar assumptions

in canoe-beam analysis while capacities were based on as-built composite

tests.

Tension failure in the gunwales corresponded to a low factor of safety

because the original design used conservative allowables prior to

checking ACI recommendations. Construction variance in the gunwales resulted with tension cracks during the

pre-competition floatation test. However, Ska’ana was not at risk of ultimate failure because local reinforcing

was carried 8 inches up the walls. To prevent further cracking, a steel wire rope was lightly post-tensioned to 25

pounds in each gunwale. The amount of post-tensioning force required to bring gunwale stress to the rupture

limit was 12 pounds. A factor of safety of 2.0

was applied to account for variance and

prevent further cracking. Despite critical pre-

conference repairs, the 2015 team witnessed

Ska’ana endure all competition demands and

dominate the waters at the Regional

Conference.

Table 3. Failure State Safety Factors

Testing and Development 2014-2015

Ska’ana | 5

Table 4. Comparison to Baseline Mixes

Figure 9. Cross Section of Three Layer Design

Structural

Lightweight

0

500

1000

1500

2000

2500

3000

0 500 1000 1500 2000 2500

Stre

ngt

h-S

pec

ifc

Gra

vity

Rat

io (

7-d

ay, p

si)

Cube Strength (7-day, psi)

Figure 10. Selection of Optimal Structural Mix

The development of the 2015 concrete mixes focused

on reducing density to meet the new floatation

requirements and improving workability for better

quality control during placing. Strength, density, and

workability were optimized by iterating several design

parameters. These parameters included water-cement

ratio, paste content, cementitious material replacement, aggregate gradation, and admixture dosage. Additional

consideration was given for streamlined design methods and improved documentation for future teams. Despite

numerous challenges, the 2015 team developed concrete mixes that led to one of the lightest and most cost-

effective canoes in recent years. A comparison of this year’s structural concrete mix to those of 2014 is seen in

Table 4; values in parentheses are for the lightweight concrete mix.

Ska’ana’s mix design team faced several obstacles at the beginning of the 2015 program. First, heavy

expenditures for the 2014 National Competition left the mix design team with a more restrictive budget than

previous years. Second, the excessive weight of last year’s canoe was attributed to poor mixture consistency and

control when placing. The poor placing control necessitated major alterations in the concrete design and placing

procedure. Lastly, the retirement of longtime faculty advisor Don Janssen created a large gap of knowledge and

experience. His retirement forced the design team to develop a novel approach to mixture design. The team

used these challenges to motivate improvements in responsible material usage, quality assurance, and

documentation for future years.

After considering alternatives, the team decided to build upon the

2013 and 2014 three-layer composite system, using previous

mixes as baselines. In the previous two years, the Huskies

implemented a three-layer composite system. The composite

system employed a variation of structural and lightweight mixes,

as illustrated in Figure 9. This build-up allows for optimization of

the mixes to match the varying strength requirements throughout

the wall and floor of the canoe. Thin high strength outer and inner

layers provide efficient localized flexural strength in the areas experiencing the highest stresses. A low density

middle layer maintains a low composite density in order to reduce canoe weight and increase buoyancy forces

when fully submerged and flooded. The Lady featured different inner and outer mixes with air entraining

included in only the inner mix. Ska’ana utilized one structural concrete mix for the inner and outer layers with

The Lady’s interior structural serving as a baseline. The reduction in both material costs and personnel hours

outweighed any minor optimizations that could be attained by

development of different inner and outer structural mixes.

The development team planned weekly lab sessions to analyze

results and determine variables to test. To account for

scheduling risk, a new design approach was implemented for

the structural mix which facilitated the concurrent development

of the structural analysis and mix design. Instead of developing

a mix based on stress specifications from the structural analysis

as in the past, the team maximized the strength-density ratio

with the intent of selecting the canoe thicknesses to meet the

demands determined by analysis, as seen in Figure 10.

Preliminary analysis set a maximum limit of 1500 psi on the 7-

day strength. Above this strength, the calculated layer thickness

required to meet strength demands was too thin to be feasibly

placed, and thus stronger, denser mixes were not considered.

2014-2015

Ska’ana | 6

Figure 11. Selection of Lightweight Thickness

0.0

0.5

1.0

1.5

2.0

2.5

3.0

0 0.2 0.4 0.6 0.8 1 1.2

Per

form

ance

Sco

re

Lightweight Concrete Thickness (inches)

Figure 12. Cylinders, Cubes, and Wire

Thickness of the lightweight middle layer was selected based on

balancing structural demands, density to pass the floatation test,

and low overall weight favorable for racing. Structural layers

were kept to a minimal 0.125 inch to maintain a low specific

gravity, while the thickness of the middle layer was varied. A

decision matrix was developed comparing desired values of

specific gravity, weight, and local safety factors to their calculated

counterparts based on the variation of the lightweight mix

thickness. Performance scores were assigned based on the ability

of each mix to achieve the desired values. Shown in Figure 11, the

thickness of lightweight concrete was selected as 0.5 inches.

Test samples consisted of 2 inch cubes used for compression and

specific gravity and, 3x6 inch cylinders used for split tensile

strength (Figure 12). Composite panels were used for final

verification of the built member. Testing methods included standard and

modified versions of ASTM C109 for compressive strength, C496 for tensile

strength, C78 and C293 for composite strength, C138 for specific gravity, and

C1437 for slump. Cube compression strengths were factored by 0.8 to account

for overestimates of strengths due to friction along the boundaries and the

nature of cube failure planes (Mackenzie). The cube failure planes can be seen

in Figure 12. Composite as-built panels were tested at the panel halves and

thirds to determine flexure and shear responses as shown on the next page in

Figure 14. For quality assurance, overconsolidated samples were prepared to

measure worst case specific gravities as an upper bound for hand-placed

consolidation in the actual canoe. In addition to typical slump measurements,

the team performed qualitative comparisons of workability by placing on

vertical and curved surfaces to simulate canoe placing conditions as shown in

Figure 13. In addition to concrete tests, samples of the 0.125 inch steel wire

rope were also tested in tension to verify the strength of the cable and crimped

aluminum ferrules (Figure 12). The slip-critical ferrules failed within 3% of 800

pounds in all samples.

Materials used in Ska’ana’s concrete mixes mimic those of previous years due

to availability of leftover materials and familiarity with their design properties.

White Portland Cement was used as the primary cement in each mix for its

aesthetic qualities, and Ground Granulated Blast Furnace Slag was used as the

primary cementitious material replacement for its low density and reduced

water demand. Metakaolin was added due to its fineness compared to other

cementitious materials and resulting improvement of particle gradation, while

CTS Komponent was utilized to reduce shrinkage of the concrete (UW, 2014).

Slag proportioning was increased by 7% for the structural, inlay, and patching

mix, which decreased density, allowed for reductions in water, and improved

the sustainability of the mixes without decreasing strength (WHRP, 2007). Higher replacements were

considered, but a sharp reduction in efficiency was observed. For the patching mix, Metakaolin was also

increased to improve workability and flow, while additional CTS Komponent was increased to mitigate surface

cracking on the exterior when the patching mix was applied in thin layers with large exposed surface area.

Similar changes were avoided in the other mixes due to observed reductions in strength. The consistency of the

lightweight mix was found to be highly sensitive to changes in cement proportioning and was unchanged.

2014-2015

Ska’ana | 7

Figure 13. Placing Assessment

Figure 14. Composite Panel Testing

Lightweight, spherical aggregates included four different diameters of

Poraver expanded glass granulate and Elemix lightweight synthetic particles.

Poraver in 0.1-1 mm range was used every mix, with the exception of the

patching mix, which used 0.04-0.125 mm Poraver exclusively for improved

ability to fill small voids. Elemix was included in the lightweight mix because

of its extremely low specific gravity of 0.04, but excluded from all other

mixes due to its low strength for the structural mix and its visibility for the

inlay and patching mixes. Additionally, the lightweight mix features 8 mm

chopped fiberglass fibers for improved durability of the lightweight cellular

structure (UW, 2014). The aggregate gradation was refined from previous years to fit a transformed Fuller’s

Curve with the typical assumed exponent of n = 0.5 (Shakhmenko). This new gradation was very effective and

led to an approximately 7% increase in the 7-day strength-specific gravity ratio of the structural mix and

significant reductions in the density of the lightweight mix due to higher Elemix proportioning.

Many admixtures were maintained from the 2014 design: Daraweld C latex polymer was used in all mixes to

improve bonding between concrete layers and improve tensile strength, Daravair 1000 liquid air-entrainer was

used in the structural mix, while Rheocell 30 liquid foaming agent was used in the lightweight mix to achieve

extremely high air contents. No air-entraining admixtures were used in either the patching or inlay mixes in

order to facilitate a smooth exterior for reduced drag and aesthetic appeal. One major change from previous

years is the addition of Rheobuild 1000, a high range water reducer, into the structural, inlay, and lightweight

mixes. The additional workability provided by a high range water reducer is generally used to create low water-

cement ratio mixes with high strengths. However, in this application, the reducer was used to lower the paste

content and reach lower densities while maintaining most of the strength and workability. An undesirable side

effect of the high range water reducer was faster slump loss for the mixtures. The slump loss issues were

mitigated with increased focus on faster concrete placing by training team members before canoe placing. Also,

to account for slump loss issues the slump of the lightweight mix was vastly decreased from previous years

which expedited placement of layers with a precise thickness.

From experience with the composite design, lower paste contents would

decrease the layer bond strength. To offset these negative effects, latex

dosage of the lightweight mix was increased. Additional measures were

taken during placing to improve layer bond strength by protecting fresh

layers from water evaporation with damp cloths while waiting for the

subsequent layer. During as-built composite flexural testing, over half of

the samples failed in interface shear/delamination between layers instead

of rupture of the glass fiber (Figure 14). Delamination was the

controlling ultimate failure after initial tension cracks formed. These

failures were not expected and a detailed analysis of the results had to

verify local composite strengths in the floor of the canoe. Comparison of

the testing results and the structural analysis on the canoe floor

determined a safety factor of 2.7 against interface shear and the design

team was satisfied Ska’ana would resist all local point loads.

To facilitate faster placing, batch sizes were increased to better match the

mixer capacity and all dry concrete materials were pre-proportioned and

bagged to minimize batching time on placing day. This also improved

quality control in batching and aided in monitoring the mass flow of concrete material going into the canoe.

After multiple iterations and assessments based on construction and structural requirements, the 2015 concrete

mixes were ready for canoe placing.

Construction 2014-2015

Ska’ana | 8

Figure 15. Mold Fabrication Stages

Figure 16. Floor Layer Schematic

Glass Fiber

Carbon Fiber

Lightweight

Lightweight

Structural

1/8”

1/2”

1/8” Glass Fiber

Structural

Figure 17. Reinforcing Layout

The 2013 and 2014 canoe mold was a donated combination of expanded

polystyrene (EPS) foam billets, a computer numerically controlled (CNC)

milling, and a durable polyurea surface treatment. Based on experience, a

donated milled/treated EPS mold was the most efficient means of

constructing a high quality canoe. The team selected a female style mold

based on the resulting high quality outer surface and successes of past

years. The fabrication stages for the milled/treated EPS mold are shown

in Figure 15. The 2015 construction team set out to build Ska’ana with a

heightened focus on safety, quality assurance, and environmental

responsibility.

The team began construction organizing the workspace. Keeping

sustainability in mind, a detailed inventory was taken to initiate

discussion on reuse and recycling of materials. The team concluded to

reuse surplus reinforcing materials from 2013 and 2014 to recycle

available materials and save costs. Timber features from the 2014 EPS

mold were stripped and resized to be placed on the 2015 EPS mold. The

remaining 2014 EPS was responsibly disposed of at a specialized foam

recycling plant. These recycling procedures set precedent for future team

practices in sustainability.

Organizing and maintaining the workspace was driven by efficiency and

safety. The 2013 and 2014 teams were burdened with limited storage,

construction space, and a hazardous working environment. Disposing and

storing of materials and equipment cleared floor space. Trip hazards and

low-lying sharp objects were cleared to improve jobsite safety. Unstable

items in high places were removed, stabilized/tied, or stored at ground

level to eliminate collapse hazards. Jobsite Hazard Analysis Forms were

implemented to maintain awareness and importance of safety throughout

construction phases. Initial organization and a continued clear worksite

increased laborer efficiency, comfort, and safety.

Fabrication of the forms occurred simultaneously with workspace

organization. Before final donations for the forms were confirmed,

alternative mold construction was researched to prevent scheduling risks.

Once the materials and services were granted, the team coordinated the

fabrication schedule and transportation of the mold between fabrication

sites until completion. The team also prefabricated gunwale forms meant

to be erected during final stages of canoe placing. Form fabrication

concluded by adhering foam letter cutouts to the mold interior to leave

letter imprinted inlays after placing.

Concrete and reinforcing placement balanced structural efficiency and

constructability. First, structural concrete was placed in a thin layer. Then,

transversely running sheets of glass fiber reinforcing were placed on the

structural concrete throughout the canoe and embedded with a thin

structural skim layer. Next, lightweight concrete was placed over the structural skim. Then, longitudinally

running strips of carbon fiber reinforcing were embedded in the lightweight concrete in the gunwales and keel.

Lastly, a final structural layer was placed with a second layer of embedded, transversely running glass fiber.

Figure 16 shows an exploded floor section. The floors slightly differed from the walls. Instead of 0.5 inch layer

2014-2015

Ska’ana | 9

Figure18. Anchor and Swan Channel

of lightweight mix, the sidewalls detailed a 0.25 inch lightweight layer. The thinner lightweight layer in the wall

lowered placing time by an hour and reduced the weight of Ska’ana by 20 pounds. Figure 17 shows the typical

reinforcing layout.

During the 2014 placing, the carbon reinforcing warped on curved surfaces. The warping required excess

concrete to fill the voids which resulted in The Lady being 100% over the design weight. To eliminate excessive

weight, carbon reinforcing was placed in the lightweight mix because of its higher flow. The higher flow mix

allowed easier consolidation around the reinforcing and eliminated the need for excess concrete. Additionally,

the contribution to canoe weight would be small if any excess lightweight concrete was used.

Following concrete placing, curing used wetted burlap cloth for two weeks in a heated moisture sealed facility.

After curing, the facility was disassembled and mold halves were parted. Improvements to Ska’ana’s mold

allowed easier access points for parting the mold with reduced stress on the canoe. Finishing began with

patching and sanding the canoe. Pigment-colored concrete was placed as letter inlays. Exterior and interior

graphics were then sketched and stained. Concrete finishing concluded by applying a silane-based sealer with a

Volatile Organic Compounds content of 39 grams per liter. The sealer applied to Ska’ana differed from the

sealer applied to The Lady to provide a better application to vertical surfaces and for significant reductions to

VOC levels. The stains remained the same as those featured on The Lady because of the vibrant results seen in

2014.

After sealing concluded, the team performed a pre-competition floatation test. During the test, Ska’ana failed to

self-surface and float unassisted. Ska’ana failed to float because water seeped into the lightweight concrete

voids. Seepage occurred through openings between the inlay lettering concrete and structural outer concrete.

Extensive patching of the interface prevented further seepage, and

foam inserts were integrated as floatation redundancy. The foam

inserts were covered with 0.25 inch fiberglass-reinforced structural

concrete, and repairs were finished with original methods.

After the floatation test, large tension cracks were observed in the

gunwales. The tension cracks formed because thickness in the

gunwales did not account for placing variance, and resultant rupture

stresses were reached. To prevent further cracking, a post-tensioned,

0.125 inch steel wire rope was placed into a channel sawn into the

gunwales. Structural concrete was consolidated around the post-

tensioned cable for bond strength. An anchor system was constructed

as a redundancy to the concrete-steel bond and to hold the post-

tension forces while the concrete strengthened. The anchor system

was constructed by sawing notches at the ends of Ska’ana, slipping

the cable through bearing plates, and then crimping the steel wire

with aluminum ferrules upon tensioning. Figure 18 shows the stern

anchor and sawn channel. All repair reinforcing and anchors were

covered with adequate structural concrete and finished with original

methods.

The 2015 Huskies pioneered numerous innovations during construction of Ska’ana. The 2015 practices resulted

with heightened emphasis on safety, quality assurance, and environmental responsibility. Ska’ana was delivered

with exceptional quality, cost/labor savings, and environmental responsibility. The critical repairs provided an

unmatched learning experience for even senior members and will provide valuable experience going into

industry. The University of Washington Huskies are excited to present their technical expertise, competitive

spirit, and powerful canoe Ska’ana at the 2015 National Concrete Canoe Competition.

Project Schedule 2014-2015

Ska’ana | 10

Design Drawing 2014-2015

Ska’ana | 11

23.50

Ska’ana

Appendix A: References 2014-2015

Ska’ana | A-1

ACI Committee 318 (2011). Building Code Requirements for Structural Concrete (ACI 318-11). ACI (2011).

ASCE/NCCC (2015). “2015 American Society of Civil Engineers® National Concrete Canoe

CompetitionTM

Rules and Regulations.”

<https://www.asce.org/uploadedFiles/Membership_and_Communities/Student_Chapters/Concrete_

Canoe/Content_Pieces/nccc-rules-and-regulations.pdf > (March 27, 2015).

ASTM (2013). “Standard Specification for Concrete Aggregates.” ASTM C33/C33M-13, ASTM

International, West Conshohocken, PA.

ASTM (2013). “Standard Test Method for Flow of Hydraulic Cement Mortar.” ASTM C1437-13, ASTM


ASTM (2012). “Standard Specification for Expansive Hydraulic Cement.” ASTM C845/C845M-12, ASTM


ASTM (2012). “Standard Specification for Portland Cement.” ASTM C150/C150M-12, ASTM


ASTM (2012). “Standard Test Method for Density (Unit Weight), Yield, and Air Content (Gravimetric) of

Concrete.” ASTM C138/C138M-12a, ASTM International, West Conshohocken, PA.

ASTM (2011). “Standard Test Method for Flexural Strength of Concrete (Using Simple Beam with Third-

Point Loading)” ASTM C78/C78M-10e1, ASTM International, West Conshohocken, PA

ASTM (2011). “Standard Test Method for Splitting Tensile Strength of Cylindrical Concrete Specimens,”

ASTM C496/C496M-11, ASTM International, West Conshohocken, PA.

ASTM (2010). “Standard Specification for Fiber-Reinforced Concrete.” ASTM C1116/C1116M-10a,

ASTM International, West Conshohocken, PA.

ASTM (2010). “Standard Specification for Air Entraining Admixtures for Concrete.” ASTM C260/C260M-

10a, ASTM International, West Conshohocken, PA.

ASTM (2010). “Standard Test Method for Flexural Strength of Concrete (Using Simple Beam with Center-

Point Loading).” ASTM C293/C293M-10, ASTM International, West Conshohocken, PA.

ASTM (2009). “Standard Test Method for Compressive Strength of Hydraulic Cement Mortars (Using 2 in.

or [50 mm]) Cube Specimens,” ASTM C 109, ASTM International, West Conshohocken, PA.

ASTM (2008). “Standard Test Method for Length Change of Hardened Hydraulic Cement Mortar and

Concrete.” ASTM C157/C157M-08, ASTM International, West Conshohocken, PA.

Janssen, Donald. Concrete Canoe Team Advisor - Reference. University of Washington Department of Civil

& Environmental Engineering, September 2014-March 2015.

LaBarca, Foley, and Cramer (2007). “Effects of Granulated Ground Blast Furnace Slag in Portland Cement

Concrete – Expanded Study.” Wisconsin Highway Research Program, January 2007.

2014-2015

Ska’ana | A-2

Mackenzie, Peter. Structural Analysis Advisor - Reference. University of Washington Department of Civil

& Environmental Engineering, September 2014-March 2015.

National Ready Mixed Concrete Association. (2000). “Concrete in Practice.”

<http://www.nrmca.org/aboutconcrete/cips/16p.pdf> (Mar. 20, 2015).

Native Languages of the Americas Website. (1998). “Wolf and the Sea.” < http://www.native-

languages.org/haida-legends.htm> (Mar. 25, 2015).

Sailboat Cruising Website. “Hullspeed and the Speed/Length Ratio.” <http://www.sailboat-

cruising.com/hullspeed.html> (Mar. 28, 2015).

Sailboat Cruising Website. “Understanding the Prismatic Coefficient.” <http://www.sailboat-

cruising.com/prismatic-coefficient.html> (Mar. 28, 2015)

Shakhmenko, Genadij, and Juris Birsh. (1998). “Concrete Mix Design and Optimization.” Riga Techniqucal

University, Department of Building Materials. <http://www.dogateknik.com.tr/teknik-belgeler/concrete-

mix-design-and-optimization.pdf> (Mar. 28, 2015).

University of Washington Concrete Canoe Team (2014). The Lady. Design Paper.

University of Washington Concrete Canoe Team (2013). Undammed. Design Paper.

University of Washington Concrete Canoe Team (2012). Hermes. Design Paper.

University of Wisconsin Madison Concrete Canoe Team. (2012). NCC Design Papers 2000-Present.

<http://canoe.slc.engr.wisc.edu/designpapers/index.htm> (March 15, 2015).

Winters, John. “The Shape of the Canoe. Part 1: Residual Resistance.”

<http://www.greenval.com/shape_part2.html> (Mar. 28, 2015).

Appendix B: Mixture Proportions 2014-2015

Ska’ana | B-1

Mixture ID: Structural Design Proportions (Non SSD)

Actual Batched Proportions

Yielded Proportions YD Design Batch Size (ft

3): 0.08

Cementitious Materials SG Amount (lb/yd3)

Volume (ft3)

Amount (lb)

Volume (ft3)

Amount (lb/yd3)

Volume (ft3)

CM1 Portland Cement 3.15 294.04 1.496 0.87 0.004 277.19 1.410

CM2 Slag 2.90 233.89 1.293 0.69 0.004 220.49 1.218

CM3 Metakaolin 2.50 73.51 0.471 0.22 0.001 69.30 0.444

CM4 Expansive K 2.98 66.83 0.359 0.20 0.001 63.00 0.339

Total Cementitious Materials: 668.27 3.62 1.98 0.01 629.97 3.41

Aggregates

A1 .1-.3 mm Poravair Abs: 35.0% 0.66 246.98 6.019 0.73 0.018 232.83 5.674

A2 .3-.5 mm Poravair Abs: 28.0% 0.57 110.44 3.084 0.33 0.009 104.11 2.908

A3 .5-1 mm Poravair Abs: 20.0% 0.41 117.34 4.545 0.35 0.013 110.61 4.284

Total Aggregates: 474.76 13.65 1.41 0.04 447.55 12.87

Water

W1 Water for CM Hydration (W1a + W1b)

1.00

213.85 3.427 0.63 0.010 201.59 3.231

W1a. Water from Admixtures 23.87

0.07

22.51

W1b. Additional Water 189.97 0.56 179.08

W2 Water for Aggregates, SSD 1.00 140.84 0.42 132.76

Total Water (W1 + W2): 354.68 3.43 1.05 0.01 334.35 3.23

Solids Content of Latex, Dyes and Admixtures in Powder Form

S1 Daraweld C (Latex) 1.00 21.44 0.344 0.06 0.001 20.21 0.324

Total Solids of Admixtures: 21.44 0.34 0.06 0.00 20.21 0.32

Admixtures (including Pigments in Liquid Form)

% Solids

Dosage (fl

oz/cwt)

Water in Admixture

(lb/yd3)

Amount (fl oz)

Water in Admixture

(lb)

Dosage (fl

oz/cwt)

Water in Admixture

(lb/yd3)

Ad1 Daraweld C (Latex) 8.3 lb/gal 53% 92.18 18.87 1.83 0.06 92.18 17.79

Ad2 Daravair 3000 8.5 lb/gal 10% 3.68 1.47 0.07 0.00 3.68 1.39

Ad3 Rheobuild 9.0 lb/gal 0% 7.52 3.53 0.15 0.01 7.52 3.33

Water from Admixtures (W1a): 23.87 0.07 22.51

Cement-Cementitious Materials Ratio 0.440 0.440 0.440

Water-Cementitious Materials Ratio 0.320 0.320 0.320

Slump, Slump Flow, in. 2.5 +/- 1 in 2.75 2.75

M Mass of Concrete. Lbs 1519.15 4.50 1432.08

V Absolute Volume of Concrete, ft3 21.04 0.06 19.83

T Theorectical Density, lb/ft3 = (M / V) 72.21 72.21 72.21

D Design Density, lb/ft3 = (M / 27) 56.26

D Measured Density, lb/ft3 53.06 53.06

A Air Content, % = [(T - D) / T x 100%] 22.1% 26.5% 26.5%

Y Yield, ft3 = (M / D) 27 0.085 27.000

Ry Relative Yield = (Y / YD) 1.061

2014-2015

Ska’ana | B-2

Mixture ID: Middle Design Proportions (Non SSD)


Yielded Proportions YD Design Batch Size (ft3): 0.12


Volume (ft3)

Amount (lb)

Volume (ft3)

Amount (lb/yd3)

Volume (ft3)


CM2 Slag 2.90 88.07 0.487 0.39 0.002 87.95 0.486

CM3 Metakaolin 2.50 34.60 0.222 0.15 0.001 34.55 0.221

CM4 Expansive K 2.98 31.45 0.169 0.14 0.001 31.41 0.169


Fibers

F1 Fiber 1 1.30 6.72 0.083 0.03 0.000 6.71 0.083

Total Fibers: 6.72 0.08 0.03 0.00 6.71 0.08

Aggregates

A1 .1-.3 mm Poravair Abs: 35.0% 0.66 56.09 1.367 0.25 0.006 56.02 1.365

A2 .3-.5 mm Poravair Abs: 28.0% 0.57 24.92 0.696 0.11 0.003 24.88 0.695

A3 .5-1 mm Poravair Abs: 20.0% 0.41 26.74 1.036 0.12 0.005 26.70 1.034

A4 Elemix Abs: 0.0% 0.04 13.37 5.103 0.06 0.023 13.36 5.097


Water


1.00

125.81 2.016 0.56 0.009 125.64 2.013


0.10

23.31



Total Water (W1 + W2): 157.77 2.02 0.70 0.01 157.56 2.01



P1 Pigment 1 (Powder Form) 1.00 0.00 0.000 0.00 0.000 0.00 0.000



% Solids

Dosage (fl

oz/cwt)

Water in Admixture

(lb/yd3)

Amount (fl oz)

Water in Admixture

(lb)

Dosage (fl

oz/cwt)

Water in Admixture

(lb/yd3)


Ad2 Rheocell 8.5 lb/gal 0% 4.60 0.96 0.06 0.00 4.60 0.96





Slump, Slump Flow, in. 4 +/- 1 in 4.00 4.00

M Mass of Concrete. lbs 623.46 2.77 622.63





A Air Content, % = [(T - D) / T x 100%] 54.2% 54% 54%

Y Yield, ft3 = (M / D) 27 0.120 27.000


2014-2015

Ska’ana | B-3

Mixture ID: Inlay Design Proportions (Non

SSD)




Volume (ft3)

Amount (lb)

Volume (ft3)

Amount (lb/yd3)

Volume (ft3)


CM2 Slag 2.90 233.89 1.293 0.69 0.004 247.45 1.367

CM3 Metakaolin 2.50 73.51 0.471 0.22 0.001 77.77 0.499

CM4 Expansive K 2.98 66.83 0.359 0.20 0.001 70.70 0.380


Aggregates

A1 .1-.3 mm Poravair Abs: 35.0% 0.66 244.93 5.969 0.73 0.018 259.12 6.315

A2 .3-.5 mm Poravair Abs: 28.0% 0.57 109.52 3.059 0.32 0.009 115.87 3.236

A3 .5-1 mm Poravair Abs: 20.0% 0.41 116.36 4.507 0.34 0.013 123.10 4.768


Water


1.00

213.85 3.427 0.63 0.010 226.24 3.626


0.07

23.70



Total Water (W1 + W2): 353.51 3.43 1.05 0.01 374.00 3.63



P1 Pigment 1 (Powder Form) 1.00 11.69 0.187 0.03 0.001 11.05 0.177



% Solids

Dosage (fl

oz/cwt)

Water in Admixture

(lb/yd3)

Amount (fl oz)

Water in Admixture

(lb)

Dosage (fl

oz/cwt)

Water in Admixture

(lb/yd3)













Y Yield, ft3 = (M / D) 27 0.076 26.978


2014-2015

Ska’ana | B-4

Mixture ID: Patching Design Proportions (Non SSD)




Volume (ft3)

Amount (lb)

Volume (ft3)

Amount (lb/yd3)

Volume (ft3)


CM2 Slag 2.90 474.88 2.624 0.66 0.004 507.94 2.807

CM3 Metakaolin 2.50 271.36 1.739 0.38 0.002 290.25 1.861

CM4 Expansive K 2.98 271.36 1.459 0.38 0.002 290.25 1.561


Aggregates

A1 .04-.125 mm Poravair Abs: 36.0% 0.99 500.28 8.121 0.69 0.011 535.11 8.686


Water


1.00

568.74 9.114 0.79 0.013 608.34 9.749


0.02

14.18



Total Water (W1 + W2): 748.84 9.11 1.04 0.01 800.98 9.75





% Solids

Dosage (fl

oz/cwt)

Water in Admixture

(lb/yd3)

Amount (fl oz)

Water in Admixture

(lb)

Dosage (fl

oz/cwt)

Water in Admixture

(lb/yd3)












Y Yield, ft3 = (M / D) 27 0.037 28.909


Appendix C: Bill of Materials 2014-2015

Ska’ana | C-1

Canoe Construction Materials Units Unit Cost Quantity Total

White Portland Cement (Type I) lb $ 0.32 47.8 $ 15.30

GGBF Slag, Grade 100 lb $ 0.07 33.1 $ 2.32

Metakaolin lb $ 0.58 11.3 $ 6.50

CTS Cement Komponent lb $ 0.34 10.3 $ 3.50

Poraver (0.04-0.125 mm) lb $ 0.70 4.15 $ 2.91

Poraver (0.1 – 0.3 mm) lb $ 0.70 30.4 $ 21.28

Poraver (0.25 – 0.5 mm) lb $ 0.70 13.6 $ 9.52

Poraver (0.5 – 1.0 mm) lb $ 0.70 14.5 $ 10.15

Elemix lb $ 3.48 1.7 $ 5.92

8 mm Fiberglass Strands lb $ 10.13 0.84 $ 8.51

Daraweld C lb $ 0.89 9.3 $ 8.28

Rheocell 30 fl oz $ 0.12 1.8 $ 0.21

Rheobuild fl oz $ 0.13 7.6 $ 0.99

Daravair 1000 fl oz $ 0.10 2.3 $ 0.24

Black Pigment lb $ 8.32 0.6 $ 4.99

CT 275 Carbon Fiber Reinforcement sq ft $ 2.97 55 $ 163.17

Fiberglass Reinforcement sq ft $ 0.80 160 $ 128.00

Sealer gal $ 25.45 1 $ 25.45

Mold Release gal $ 16.00 1 $ 16.00

Stains pt $ 50.00 3 $ 150.00

1/8” X 4’ X 8’ Plywood sheet $19.00 1 $19.00

Insulating Foam Sealant fl oz $5.00 4 $20.00

1/8” Ferrules EA $2.00 4 $8.00

1/8” Steel Wire Rope EA $17.00 1 $17.00

Subtotal: $ 647.22

Mold Construction Materials Units Unit Cost Quantity Total

Mold EA $ 8025.00 1 $ 8025.00

¼” 4’ X 8’ Plywood sheet $ 19.00 0 (reused) $ 0

Foam Lettering EA $ 7.00 1 $ 7.00

Subtotal: $ 8032.00

TOTAL COST $ 8592.22

Appendix D: Example Structural Calculation 2014-2015

Ska’ana | D-1

2014-2015

Ska’ana | D-2

Appendix E: Repair Procedures Report 2014-2015

Ska’ana | E-1

2014-2015

Ska’ana | E-2

Figure E-2. Bow Damage Right Figure E-1. Bow Damage Left

Figure E-3. Bow Damage Front Figure E-4. Before Conference Damage

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