Between June 29 and July 1, 1995, 22 teams of civil engineering students from universities across the country met on a rain-swollen Potomac River in Washington D.C., to put their engineering (and paddling) skills to the ultimate test: racing canoes they designed and built from concrete in the 1995 American Society of Civil Engineers National Concrete Canoe Competition.
The competition showcases civil engineering ingenuity and creative uses of concrete, as students develop innovative ways to make a light, fast concrete vessel that can take top honors in a series of grueling races. Though the canoe races are certainly the most exciting part of the competition, a team's placement in the races actually makes up only 40% of its overall score. The remaining 60% of the score is based on academic performance, which includes a design paper (25%), display board and oral presentation (15%), and the finished canoe (20%).
ASCE civil engineering students strive each year to build stronger, lighter, and faster concrete canoes. Most canoes are 17 to 18 feet long depending on the hull design. Canoe weight has decreased significantly. In 1989 the winning canoe weighed about 185 pounds; this year's winner weighs only 88 pounds. This dramatic weight decrease is primarily due to more sophisticated mix designs that incorporate special admixtures and lightweight aggregates and to thinner canoe walls. Most students chose high-tech aggregates to make a light yet strong concrete mix. This year several students used ceramic or glass beads, microscopic silica spheres or even plastic foam beads similar to those found in beanbag chairs. Students also increase the strength and reduce the weight of their canoes using innovative reinforcement materials, although the winning team used only simple half-inch square steel mesh.