So, it turns out that there’s a weight limit for the concrete bowling ball competition (ours was clearly
way too heavy to use anyway). Fortunately, being engineers, we we able to find an alternate use for it as a soccer ball, kicking it around campus on our way to the Geotech competition. Note that a 25-pound sphere can pick up a lot of momentum…
We need to make a cross-section of our canoe showing the three layers of concrete and two layers of reinforcement for our canoe display, so we did a mini-pour-day. The one section took only about 90 minutes and just a few people; much more efficiently than pouring the actual canoe.
Meanwhile, the canoe’s almost ready to de-mold…
A low angle of the full canoe
Another creative canoe angle
Working on the second layer of the section
Dry concrete elements await mixing
We filled a few cylinders to strength-test our mix one last time
Packing cylinders. We ended up with a sizable amount of extra mix.
The finished cross-section.
The canoe wants bulkheads!
First batch of mix
Trimming bulkheads, and cleaning up
Patching the top edge of the canoe
Fitting, trimming, fitting, trimming…
We started running into a lot of balloons in our trimming…
Placing concrete patches
Cleaning out the stray foam pieces
Edges look good
One bulkhead done!
Erin: we’re going to need to take like six inches off the top. Nick: okay, I’ll just go for it. Both: uh, there go all of our air pockets…
We had a couple leftover balloons to put inside popped balloon pockets
Mixing another batch of concrete
We ended up stuffing the balloon pockets with the foam we chopped off
Patching done, ready for bulkheads!
Bulkhead patching almost done
I guess it could look worse…
We still had to place the third layer of concrete on the ends under the bulkhead
Wait, our bulkheads are both 6″ too long? … let’s chop them down more…
Packing in the bulkhead
Placing this goes way faster than the rest of the canoe
One down, one to go
One more mix!
bulkheads look good
And the humidifying setup is reconstructed. DONE.
Photos by Nick Halsey, Erin Khan, and Lance Hill. Click on an image to see it full size and scroll through them.
Trimming the reinforcement in the mold
Attempting to assemble the (male) mold cutouts…
The 2nd layer of reinforcement standing by on the male mold
Dry concrete is awaits mixing
The madness is about to begin…
Frantic concrete mixing
Deliberating over bow design
Packing the first layer
Adding the first section of reinforcement
packing the second layer, over reinforcement
The canoe team places concrete into the canoe mold during the concrete canoe pour day, 2013
Starting to place concrete over the second layer of reinforcement
We used some spare bricks to hold the reinforcement in place while we mixed more concrete.
Brief break, waiting for more concrete to lay over the 2nd layer of reinforcement.
Waiting for more concrete for the last layer
Packing in the last layer.
The canoe is poured!
Now we prep the concrete canoe for curing, a 4-week process in total.
We needed the whole team to construct the canoe’s plastic shell
The canoe will cure in this sealed, humidified shell for the next week.