Close call: ASCE's Illinois Tech team casts Concrete Canoe (pt 2)

by AARON GRUDOWSKI, Illinois Tech Civil Engineering Student, Concrete Canoe Captain | March 15, 2017

This is the second article in a three-part series. Each year, roughly 200 ASCE Student Chapters go head to head in the annual Concrete Canoe Competition, where student engineers design, construct, and race a canoe made of concrete against other university teams. This year, we're once again following the Illinois Tech team as they try to make it to Nationals in Colorado this June 17-19.

Saturday February 11

You have 1 new message from ASCE IIT: Concrete Canoe Casting set for Saturday February 18 at 4:00 p.m.

Saturday February 18 (one week later)

“Hey guys what time is it?.... 4 p.m. what? We are supposed to start casting right now, and we aren’t even done with the mold yet! We better get going soon.”

Close call: Relieved we double checked the molds before pouring the concrete

four hours later...

“Alright, that should just about finish up the mold. Before we cast, let’s just check to make sure the male mold fits into the female mold. Everyone help lift it up and place it in the female mold… Oh no. We’ve got a problem...”

Although we had carefully designed the molds so that they fit into each other without a problem, we were still a little off. As the hull of the canoe began to angle inwards, the two molds became misaligned, and they intersected toward the front of the canoe. Had we not checked to make sure that the molds were properly positioned, the canoe would have literally been cut into two pieces by the molds. Fortunately, we took precautions, and we saved ourselves from major disaster. Now, this small issue just had to be fixed.

Saturday evening, 10 p.m.

“Okay, let’s do this. The molds are fixed, the mixtures are ready to go, and we are all set to cast. We need two people for measuring water and Superplasticizer, three people for mixing, and six people for pouring the concrete into the mold. Alright — ready, set, go!”

Fortunately for the team, after the issue with the mold, the rest of casting went pretty smoothly. In order for concrete to bond to itself, it needs to be cast within two hours. Otherwise, it will start setting and hardening, and its strength upon curing will be much lower. This could lead to a canoe that is not seaworthy.

Overall, casting took around 4 hours. Fortunately, as the team mixed and poured the concrete, there was never a point where concrete was exposed to air for more than two hours. A successive layer was always poured onto it prior to the initial setting time, avoiding the any issue of bonding. As the buckets of concrete were mixed, the clumpy mixture was poured in between the molds, and a concrete vibrator was used to ensure that the concrete consolidated and did not leave any voids. It is a tricky process because although the vibrator should do its job, there is no way to see whether or not the concrete is properly consolidating. We would just have to wait until we removed the mold to see.

Packing the mold with our concrete mixture. Read more about what we used in part 1!

Sunday February 19, 2:15 a.m.

“Woohoo! It’s done. Nice job guys. We really want to thank you all for sticking with us so late (or early, I guess!), in order to make sure the canoe was finished. We of course have a long way to go, but this was a huge step, so thank you. It went smoother than last year’s casting, so hopefully come March 31, we will be successful.”

Worth it: Our team bonded over long hours and late nights.

Although we do still have a long way to go, and we will see how the canoe actually looks once it is removed from the mold, casting was a huge step towards our end goal. That’s one of the coolest things of being a part of the concrete canoe team. None of us are getting paid to do this, there is no reward for doing it, and it takes up a whole lot of time!

However, when we really need the help, everyone comes together and lends a hand, even it means working long hours. Being a part of the team helps form lasting friendships with students from all different specializations of civil engineering, and in our team’s case, a few math majors as well. Although we will never be building a concrete canoe once we become licensed engineers, the team teaches us how to work with a team. It provides us with invaluable knowledge about concrete. It exposes us to the ups and downs of all real-world projects, and it helps us get accustomed to everything not always going our way. Most importantly, it helps us have fun. It can be stressful, but in the end, without concrete canoe, life just wouldn’t be an adventure.