UMass Amherst team proves that concrete floats.
Conventional wisdom says that when you put a solid concrete object in water it’ll sink — like a brick.
But a team of civil engineering students from UMass Amherst proved otherwise: concrete, when carefully formulated, and molded into just the right shape, can float. What’s more, it can become a sea-faring vessel nearly as fast and as strong as any traditional fiberglass or aluminum canoe.
On April 25, the UMass Amherst Concrete Canoe team took top honors in the New England Regionals of 17th annual National Concrete Canoe Competition held near Fairfield, CT. They bested an eight-team field, including the defending champ, the University of Rhode Island. In June, the UMass Amherst team heads to Washington, DC, for the national championship where it will face 22 other teams from across the country. The event is sponsored by the American Society of Civil Engineers to challenge future engineers to come up with fast, strong boats using an unconventional material.
At the competition, teams participated in five on-water races, gave a technical demonstration of their boat’s design and construction, submitted an academic paper explaining their canoe’s underlying engineering for critical review , and endured a peer critique of the boat’s aesthetics. The UMass Amherst boat— featuring a great white shark motif, complete with fierce teeth painted on the bow — finished first in the review of its academic paper, took second in the racing competition, and a close second on the technical presentation. The team came in third in aesthetics — perhaps the shark was a bit too scary.
The real question is, how does concrete float? Team captain Andy Jeffrey explains with glee that it all comes down to the “secret ingredient” in the concrete aggregate. The UMass Amherst engineers came up with a form of glass microspheres that they mixed in with Portland cement powder and other substances. These microspheres trap air pockets and make the finished concrete less dense than water.
The team then spread its innovative concrete in a thin coat over a foam mold, carefully designed to be hyrdodynamic and to take into account the specific properties of concrete. They used fiberglass mesh to reinforce the concrete – each year a few teams’ boats seem to crack in half during the race. It was something the UMass team wanted to avoid.
The UMass Amherst team is entirely student-run. Its members undertook the concrete canoe project in their spare time. They were helped by a faculty advisor and an alum who competed on last year’s team. “We had to manage the project involving planning, design, fundraising, even the artistic design,” said Jeffrey. “It was a wonderful learning experience.”
Team members include: Christie Bonczar, Sean Foster, Aaron Judge, Andy Jeffrey, Carl Johnson, Gershon Larson, Kyle Murphy, Mike Mitchell, Chris Racine, Ammie Rogers, Mike Robertson, Nate Roy, Jack Simonis, Lynne Starek, Matt Sullivan, and Brien Waterman. Faculty Advisor: Dr. Sergio Brena
More info: 2004 National Concrete Canoe Competition