2021 Concrete Canoe

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TABLE OF CONTENTS

1.0 FOCUS AREAS SELECTION PROCESS ................................................................................................. 1

2.0 SUMMARY OF VALUE ADDED ............................................................................................................. 2

3.0 SIMPLIFIED MIX DESIGN ....................................................................................................................... 2

4.0 MENTEE PROGRAM................................................................................................................................. 3

5.0 REFERENCES ............................................................................................................................................ 7

Figure 5: Mentees watching and learning how a slump test is performed .............................................................. 5

Figure 6: Mentees making concrete cylinders for the mix design testing .............................................................. 6

Figure 7: Mentees hand-mixing concrete ............................................................................................................... 6

TABLE OF TABLES

Table 1 Decision Matrix ......................................................................................................................................... 1

construction of a full-scale canoe, construction of scaled-down canoe, extensive laboratory materials testing,

improvements to the current mentee program, simplification of a complex mix design, and construction

techniques. To narrow down the selection process and choose the final two enhanced focus areas, the team utilized

a decision matrix. Within the decision matrix, the criteria that held weight for the decision were innovation (25%),

innovation is the reason for this competition and the greatest challenge posed from the Request for Proposals

(RFP) every year. Sustainability is always an important criterion for NAU teams, especially because the

University prides itself on sustainability, being nestled in the beautiful Ponderosa Pine Forest of Northern

Arizona. Cost was one of the most important criteria because NAU canoe teams are always responsible for raising

their own funds and the team recognized that fundraising may be more difficult with COVID-19. Number of

people necessary was the next highest weight with COVID restrictions allowing a maximum of 10 people for

gatherings, the team recognized that some of the possible focus areas may be difficult to complete with only that

number of people. Finally, the lowest two weighted criteria were material availability and overall theme. Material

availability refers to location of materials relative to Flagstaff along with the market costs of these materials. The

criteria. As can be seen in Table 1 above, both the simplified mix design and the mentee program scored high in

innovation, sustainability, cost, number of people necessary to be together at once, and material availability.

simplified mix design, added a technical value to the design of the final product. The second, improved mentee

program, added a project management and inclusion value to the overall project.

suppliers. The team members were constantly in contact with local suppliers in an attempt to only use locally

sourced materials. This enhanced focus area also forced the team to experiment with materials that may not be

mixes as well as the understanding of different aggregates or admixtures.

project more than the team had originally anticipated. As expected, inclusion of more people allowed for more

testing and design to be completed in a short amount of time, increasing the project’s efficiency. But an

inadvertent result of focusing on the mentee program was an added element of fresh knowledge and innovative

goals. An example of this is the removal of an air entrainer admixture, which was originally implemented to

reduce the weight of the mix. After a trial was done, the air entrainer admixture was found to have minimal impact

on the weight of the mix, but a negative impact on its strength. Thus, it was more appropriate to remove it. Another

example the replacement of an aggregate, Ultralightweight-Foamed Glass Aggregate (UL-FGA), which was

completely replaced following the addition of expanded Perlite into the mix. Perlite is lighter than the UL-FGA

and is a naturally occurring material generally used in horticulture and insulating concrete. Also, the only suppliers

4 admixtures were used along with two aggregates, two cementitious materials, and 8mm fibers. These simple

components formed to create a composite that has a plastic density of 93 pcf and a compressive strength of 2250

psi. The use of one type of fiber, and that a short type of fiber, was enough to provide the concrete a tensile

strength of 333 psi. This is about twice the strength of previous NAU teams who used a combination of two fibers

or more [1]. To obtain the results for the compression and tensile strengths ASTM C39 & ASTM C496 testing

mentee program throughout the past four years. Each year, there were less mentees involved in events such as

mix design and testing. This trend of decreasing mentee involvement was noticed when looking at past teams’

presentations and pictures. It could clearly be seen that a few years ago there was a large group of mentees

involved in work like the canoe construction as well as weekly mixes. As the years went on, less and less mentees

were seen involved in the technical work. Understanding the great commitment required to construct a full-scale

canoe, it was decided that sustaining and developing the mentee program was crucial to the success of the concrete

canoe program at NAU. The team recognized that COVID would pose many issues, so it was decided that the

but will benefit future concrete canoe teams.

management skills and inclusion. To complete this goal, this year’s team began by recruiting underclassmen in

the ASCE student chapter that showed interest in the project. The opportunity was also opened up to students not

yet involved in NAU ASCE through the general engineering department’s email list. This way, students who may