Strategies to Improve Sustainability of Concrete Pavements

Abstract: The construction and operation of highway and airfield pavements are significant sources of greenhouse gas (GHG) emissions in the transportation sector. These emissions occur at all stages of the pavement life cycle, including the production of the materials used to build pavements, construction processes, operational use of the pavement, maintenance and rehabilitation activities, and the processing and disposal of pavement materials at the end of service life.
This paper details a study that was conducted to identify strategies to improve sustainability and reduce life cycle GHG emissions associated with concrete pavements through changes to materials, design, and construction practices. First, emissions associated with concrete materials were estimated from previous studies in the literature, as well as publicly-available data sources for concrete and common constituent materials. Next, baseline concrete pavement case studies were established based on typical designs used at airfields and other types of pavement applications according to United Facilities Criteria (UFC) specifications for Department of Defense (DoD) facilities.
The study then considered a variety of different strategies to reducing life cycle GHG emissions for these pavement cases. These strategies involved making changes to typical practices in five primary categories, including pavement design methods, concrete materials and mixtures, construction processes and equipment, maintenance activities, and rehabilitation practices. These strategies had a variety of impacts on the baseline concrete pavement cases, including to the amount and types of materials used to build the pavements, pavement service life, the types of equipment and activities involved in construction, and maintenance and rehabilitation activities throughout the pavement life cycle. From there, estimates were calculated for the potential savings in GHG emissions associated with each of these strategies.
The results of this study provide insight into the relative effectiveness of a wide variety of methods for reducing GHG emissions for concrete pavements, including strategies that are easily implementable today, as well as those that could offer great benefits as new technologies mature over time. These findings should prove highly valuable for practitioners when considering the relative costs and benefits of implementation of these strategies for reducing GHG emissions, and in future implementation of methods such as life cycle assessment (LCA) in pavement design and planning.