You're building what?!
 

A concrete canoe, yes I said concrete.

Is it really made of concrete?
 

Yes, although not the concrete you see everyday.  Most concrete uses gravel and sand as aggregate, our concrete uses very small glass bubbles (called K1 microspheres).  The bubbles are very lightweight, this is how we get concrete that is less dense than water.

There are also two types of reinforcement in the canoe - short nylon fibers that are mixed into the concrete and a kevlar mesh that is layered with the concrete.

Will it float?

 
Steel ships float, why shouldn't our concrete canoe?

But yes not only with the canoe float, it will have to pass a sink test where it is pushed under water.  If it surfaces on its own we pass.  Passing the sink test is achieved by using concrete which is less dense than water.

How did you build it?
 

We used a mold made of styrofoam and covered in plastic sheeting.  We placed by hand two layers of concrete with the kevlar mesh in between.

How long did it take?
 

Molly and Chris began work on the design in late January. Construction began mid to late March. The competition took place April 26 - 27.

What will you do with it?
 

Race it!

There are five events: men's and women's endurance, men's and women's sprint and a four-man co-ed sprint. This year we won the women's endurance and the co-ed sprint.
 

 

to see pictures of all of this check out the photo gallery