www.acpa.org Quarter 1, 2022 19 FHWA Enthusiasm for Environmental Considerations “Infrastructure decisions need to consider multiple factors, such as economics, safety, project timeline, material availability, social, and environmental impacts,” said Migdalia Carrion, acting Sustainable Pavements Program (SPP) Manager for the Federal Highway Administration. “While there are significant research needs, there are also many well-known strategies that are readily implementable.” Carrion pointed to tools such as Environmental Product Declarations (EPDs) that can be used to benchmark the GHG emissions of infrastructure using life cycle assessment methods, identify opportunities for using recycled materials, and select designs that reduce the environmental impact without reducing the performance of a pavement system. “Lessons from resilience research, especially those pertaining to the changes in a pavement’s long-term performance after it has been inundated, are already informing ways in which a base is treated,” she added. “Sustainability and resilience are key components of the Infrastructure Investment and Jobs Act (IIJA) and the current Administration,” said Carrion. “Additionally, states have shown increased interest in including these topics in the decision-making process in the past years.” Some specific examples of sustainability strategies include: • State and local legislative actions such as Buy Clean laws in California and Colorado, with similar legislation being considered in several other states. • Net-zero pledges made by the Port Authority of New York and New Jersey. • Development of tools such as eLCAp in California. • Programs like the Sustainable Pavements Program in Arizona Department of Transportation. “In the domain of resilience, there have been many notable efforts to prepare, respond, and recover infrastructure assets from extreme weather events,” said Carrion. “State DOTs are also required to integrate the risk of climate change and extremeweather events into their life cycle planning and Transportation Asset Management Plans.” Many opportunities exist for the agencies to obtain additional funding and grants to support the initiatives related to sustainability and resilience, said Carrion. The IIJA defines several possible venues, including Innovative Project Delivery, National Highway Performance Program, and the Rural Grant Program. “Additionally, our pooled fund enables financial and technical assistance for agencies interested in integrating sustainability and resilience into their decision-making processes, and we are developing guidance.” “We can’t afford business as usual moving forward,” saidWathne. “Long-life pavements that are sustainable and resilient are important.” He added, “We have to embrace a new way of thinking, embracing long life, sustainable, and resilient solutions given the once-in-a-generation investment we are making as a nation into our transportation infrastructure.” Traveling the Road to Carbon Neutrality Industry efforts to reach carbon neutrality include a number of tactics that move the industry to a goal of carbon neutrality in 2050. These include: » Alternative cements: 20% fly ash replacement of cement and Portland-Limestone Cement produce greener products. » Reuse: Recycled concrete aggregates can be used in new concrete with finer material and incorporated into the aggregate base. » Reduced cementitious content: Paving with optimized aggregate gradations allows for a reduction in cement content and improves durability and smoothness. » Operational energy: Cement plants can operate with alternative and renewable energy sources to reduce GHG impacts. » Design optimization: Eliminate excessive overdesign to reduce concrete consumption. » Carbon uptake: Concrete absorbs carbon dioxide through the carbonation process. In a paper published in the Proceedings of the National Academy of Sciences, researchers found that, if reduction strategies were implemented, the emissions associated with pavements and buildings between 2016 and 2050 could fall by up to 65% and 57%, respectively, even if concrete use accelerated over that period. These are close to U.S. reduction targets set as part of the Paris Climate Accords. The solutions considered would also enable concrete production for both sectors to attain carbon neutrality by 2050. Reference: American Concrete Pavement Association. Making the Grade on Infrastructure Sustainability. According to the Portland Cement Association’s Roadmap to Carbon Neutrality, for all the concrete produced in the U.S. between 1990 and 2018, more than 300 million metric tons of CO2 will be absorbed and sequestered by concrete over its service life.1 References: 1. Roadmap to Carbon Neutrality. Portland Cement Association. 2021. www.shapedbyconcrete.com.
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