The United States has a bridge infrastructure issue. There are currently over 600,000 bridges in the United States. About 10% of these bridges are structurally deficient. The Federal Highway Administration defines Structurally Deficient (SD) as a classification given to a bridge which has any component (Deck, Superstructure, Substructure or Culvert) in Poor or worse condition [code of 4 or less], this term will be defined in accordance with the Pavement and Bridge Condition Performance Measures final rule, published in January of 2017. This does not necessarily mean the bridges are dangerous but rather that they are in need of repair.
Approximately 200 million Americans travel across structurally deficient bridges every day (CNN). Many of these bridges are more than 50 years old and constructed with concrete and steel with a design life of 50 years. Technologies are now available that can create longer-lasting and stronger bridges at a low cost. Bridges using composite materials do not require maintenance and have among the lowest life cycle costs of any bridge. When bridges are rated as structurally deficient it means a major component needs repair. Often concrete bridges with steel rebar begin to literally crumble as the rebar expands due to corrosion from deicing salts and environmental conditions.
Building with composite materials can save money in the long term because they have been tested to last about twice as long as a traditional bridge. Replacing crumbling bridges the same as in the past is like replacing all the light bulbs in your house with filament light bulbs. They are cheaper than LED or CFL light bulbs but you're going to spend more money overall by replacing them twice as often and they will use more resources to keep running. Traditional bridges also require the use of heavy equipment which can be costly, create emissions.
A large investment in infrastructure for the future is needed. Finding long term solutions to our problems is the way forward. Here at AIT Bridges, a division of Advanced Infrastructure Technologies, we are working hard to find solutions to our nation's infrastructure problems. We are starting with bridges. We currently have 2 bridge designs: A composite arch bridge, which can be erected in a matter of days and manufactured anywhere in the world, and a composite girder bridge, a comparable replacement to steel and concrete girder bridges. Using composite materials is the future of the infrastructure industry, but has seen resistance in the industry. Our bridge fixes the problems that traditional bridges have and is a more sustainable and resilient solution. Our arches have been tested to last over 100 years. We also use composite rebar in our bridges which makes the concrete it reinforces last much longer. Of the 30 bridges we have engineered since 2010, none have needed any maintenance so far.
Ahmed, Saeed. “More than 54,000 Bridges in the US Need Repair, Says This Study.” CNN, Cable News Network, 3 Feb. 2018, www.cnn.com/2018/02/02/us/2018-structurally-deficient-bridges-trnd/index.html.