Reducing carbon dioxide emissions through structural health monitoring of bridges

Reducing greenhouse gas emissions including carbon dioxide (CO2) is central to minimizing the human contribution to global warming. Industrial activities and transportation are some of the main contributors to carbon dioxide emission. Bridges are the key element in the transportation system and many of them are reaching the end of their designed service life. Replacing bridges requires a significant amount of construction materials and equipment, which will lead to significant carbon dioxide emissions. In this work, we conclude that carbon dioxide emission can be reduced by applying structural health monitoring (SHM) instrumentation and techniques to bridge management. In this work, two medium span steel girder bridges have been used to study the impact of the application of SHM on the emitted carbon dioxide. From two monitored bridges traffic load strains were used to monitor the load distribution factor and neutral axis position of each girder. This data can be used to extend the service life of these bridges. By extending the service life of a bridge, the average annual carbon dioxide emission associated with the bridge is reduced. Considering the emission due to material production and construction, the carbon dioxide emission due to bridge reconstruction will decrease by 9-17% under the assumption that the application of SHM will extend the service life of a bridge by 5-10 years. Data from Federal Highway Administration (FHWA) for the state of Iowa, which includes the number of structurally deficient bridges, was used to estimate the short-term and long-term cumulative CO2 emission for a fleet of bridges. It was concluded that if all structurally deficient bridges (rating 3 or less) in Iowa were replaced for the 2000-2019 time period, the cumulative CO2 emission would have been 4,38,483 tonnes. However, if SHM were to be applied and extended the service life of 80% of these bridges by 5 or 10 years the total emission would have been reduced to 2,84,048 tonnes or 1,75,695 tonnes.