Despite bridge widths of over 100 feet, only four box girders will be used for each structure. Diaphragms between the boxes will also be box-shaped, exposing smooth surfaces along the entire length of the bridge. The unique design of the V-piers allows for long pier spacings of up to 400 feet, creating the desired open and light appearance while reducing the number of expansion joints and associated maintenance requirements. However, because each V-pier provides dual support points for the girders, the girder spans are reduced and can be erected quickly and economically. The estimate of total steel to be used in the box girders is approximately 85,000 tons.
Steel is the most recycled material on earth .
It's friendly to the environment, making it a natural material to use in the Potomac River crossing. AISI is a non-profit association of North American companies engaged in the iron and steel industry. The Institute is comprised of 48 member companies, including integrated and electric furnace steelmakers, and 175 associate and affiliate members who are suppliers to or customers of the steel industry.