Concrete Canoe Project
2021
While conventional concrete is typically used in stationary structures that must withstand high compressive strengths, the material can be applied to many diverse types of design problems. These applications require a wide variation in the mechanical and material properties of the wet, setting, and cure material. One such example is the fabrication of a concrete canoe, where the design restraint is density. For this application, a lightweight concrete mixture that can withstand moderate tensile forces is desired. For this reason, lightweight aggregates and cement additives were supplemented to reduce the density for floatation of the canoe. Polymer admixtures were supplemented to alter the wet properties to lower the workability for manipulating the concrete, along with a reduction in the water content. Through the implementation of expanded glass as a lightweight aggregate and fly ash as a cementitious additive, the density of the concrete was reduced to roughly 80 to 90 pounds per cubic feet, where the aggregate accounts for 55% of the total volume. The use of a latex admixture and a super-plasticizer admixture resulted in an alteration of the wet properties of the concrete such that both the workability and the water content was decreased.
Acting as a leader of my senior capstone team, I led a team of five engineering students in the research, development, and fabrication of a concrete canoe, a national competition hosted by the American Society of Civil Engineers. As the undergraduate engineering program at Saint Vincent College is still young, only one previous unsuccessful attempt was made. Through disciplined research, benchmarking, and material testing a more successful concrete canoe prototype was developed using a styrofoam male mold fabricated from six inch sections of high density polystyrene being formed by a hot knife using CNC cut wooden rips as guides for the knife. The canoe model was shortened to 10 feet for reduction in organization and labor needs, as they could not be met with the given timeline for a canoe within the standards of the competition (minimum length of 18 feet).