Nanotechnology

Abstract

This paper outlines cement and concrete properties that challenge engineers and discusses the benefits that could be derived from changes in the smallest structure of cementitious and other concrete materials. Concrete is the most widely used building material in the world. Roman concrete structures still exist today. Even with concrete's versatility and durability, certain properties continue to pose challenges. The ability to modify essential molecular building blocks provides the potential to make great strides in reducing or eliminating numerous mechanisms that can compromise the life of concrete. This paper discusses current durability challenges specific to transportation structures—both bridges and pavements—and the role that nanotechnology can play in addressing these issues. In structural concrete, applications could include improved tensile strength, increased ductility, reduced permeability, and reduced shrinkage. These enhancements could significantly reduce maintenance costs and greatly extend the life of most structures. Reduced shrinkage, modification of the hydration process, minimized thermal movement, reduced permeability, and improved workability would greatly extend pavement life. Nanotechnology could play a key role in environmental stewardship through significant reduction in the carbon footprint, as well as by making the cement production process more efficient. Properties that adversely affect the construction process are also feasible applications of this technology. Other modifications of the properties of concrete that could greatly increase concrete life include the following: decreasing volume change, improved mechanical performance, greater freeze–thaw resistance, reduced water migration, improved air system stability, improved properties of marginal-quality aggregates, and improved curing methods.