Categories: Issue 76 May/June 2014

Julie Buffenbarger, FACI, LEED AP, Lafarge

Fig. 1. Nearly 80 years after it was first constructed, the Hope Memorial (Lorain-Carnegie) Bridge is “complete.” In 2013, a protected bikeway opened, making the street safer, more family friendly and conveniently accessible for pedestrians and bicyclists who would prefer not to ride in the street to cross the Cuyahoga River valley. The $4.5 million investment is consistent with the Cleveland’s Complete and Green Streets law, which requires sustainable transportation options be incorporated into new road projects.
Fig. 1. Nearly 80 years after it was first constructed, the Hope Memorial (Lorain-Carnegie) Bridge is “complete.” In 2013, a protected bikeway opened, making the street safer, more family friendly and conveniently accessible for pedestrians and bicyclists who would prefer not to ride in the street to cross the Cuyahoga River valley. The $4.5 million investment is consistent with the Cleveland’s Complete and Green Streets law, which requires sustainable transportation options be incorporated into new road projects.

(Part I of a two-part series)

The nation’s economy and quality of life require highway and roadway systems that provide a safe, reliable, efficient, and comfortable driving experience. The fact that these structures are relied upon en masse is what renders communities vulnerable when these infrastructures fail from climatic or manmade events.1-5 Across the U.S. and worldwide, the state of transportation infrastructure has reached a critical stage. Aging roads, bridges and other assets, many first built in the 1950s, are currently supporting the demands of increases in use, far beyond the originally engineered capacity and well beyond the intended service life expectations.6-7 With this increased capacity and usage in conjunction with increased climate change instabilities (natural or man-made) comes accelerated deterioration of roadways and bridges1-5

Highway bridges comprise a critical link in infrastructure, numbering 607,751 for the entire US network. Maintenance to meet modern requirements of strength and serviceability is a necessity. In the 2013 National Bridge Inventory, 63,522 bridges (10.5%) were categorized as structurally deficient (requiring significant maintenance, rehabilitation or replacement) and 84,348 (13.9%) were categorized as functionally obsolete (below current design standards, e.g. narrow lanes or low load capacity) indicating an imminent need for repair or replacement.8 Repairing existing bridges is extremely time consuming, often economically inefficient and logistically disruptive, since it results in long traffic and commerce interruption.

Today, transportation agencies are challenged to plan, build, and operate “sustainable” transportation systems that – in addition to achieving the important goals of mobility and safety – support a variety of asset management, environmental stewardship, climate mitigation/adaptation, and resilient infrastructure objectives. As stated by the American Association of State Highway and Transportation Officials (AASHTO), the sustainability of the transportation system is critical, as transportation is responsible for 10% of the global gross domestic product, 22% of global energy consumption, 25% of fossil fuel burning, and 30% of global air pollution and greenhouse gases.9

The Centre for Sustainable Transport in Canada identifies the following attributes of a sustainable transportation system:

  • Allows the basic access needs of individuals and societies to be met safely and in a manner consistent with human and ecosystem health, and with equity within and between generations.
  • Is affordable, operates efficiently, offers choices of transport mode, and supports a vibrant economy.
  • Limits emissions and waste within the planet’s ability to absorb them, minimizes consumption of nonrenewable resources, limits consumption of renewable resources to the sustainable yield level, reuses and recycles its components, and minimizes the use of land and the production of noise.10

Alongside the transition to a more sustainable society, increasing infrastructure’s functional resilience to climate change impacts is a high priority, to help protect the economy and its future growth. Functional resilience is defined as a structure’s capacity to provide viable operations through extended service life, adaptive re-use and the challenges of natural and man-made disasters.11

The US Department of Transportation Center for Climate Change and Environmental Forecasting strategic plan states that climate change will likely have significant impacts on transportation infrastructure. Achievable reductions of climate change impacts on transportation infrastructure are attainable through:

  • Fostering strategies to avoid, mitigate or adapt to the potential impacts of climate variability and change on the transportation system;
  • Promotion of cost-effective strategies that reduce greenhouse gas emissions while supporting transportation safety, mobility, efficiency, and energy security; and
  • Establishment of a leadership role on transportation and climate change issues by involving the transportation community and coordinating related USDOT programs and policies.12

The case for adapting infrastructure to climate change compelling. Bridge and highway infrastructure are an increasingly interconnected network of high-value assets with long operational lifetimes. The challenge and commitment to build climate resilient infrastructure with more secure, energy efficient and environmentally sustainable materials and practices is not a separate or mutually exclusive task, but interconnected to ensure best value from this investment.13,14

Designing for Sustainability and Resilience

Sustainable and resilient bridge design requires an integrated, long-term holistic view of all phases of the project: planning, designing, constructing, maintaining, operating, repair/rehabilitation, then final decommissioning and disposal at the end of its service life. The responsibility of a sustainable design team does not lie solely with aesthetical impact and functional performance, but also with key concerns such as integration of context-sensitive solutions, awareness of societal and biodiversity impacts, life cycle costing, climate mitigation/adaptation, and a minimizing the impact on the environment, society and the economy throughout the bridge’s life (Table 1).

EnvironmentalSocialEconomic
Ecology & BiodiversityCommunity InteractionLife Cycle Costs
LandscapeCommunity LiveabilityProject Management
Stormwater ImpactsHuman Health ImpactsFinancial Sustainability
Construction Waste ManagementHistoric & Cultural PreservationEconomic Analysis
Material UseScenic & Natural QualitiesSafety Programs
Energy & CarbonSafetyLand Use
Reduce, Recyle & ReuseEquityOperation & Management Systems
Reduced Energy & EmissionsStakeholder InvolvementBridge Management Systems
Noise PollutionTransportation ImpactsEnergy Efficiency
ResiliencyResiliencyResiliency
Table 1. Sustainable Impacts for Bridges15-19  

Bridge engineers have been practicing many sustainable concepts through the decades – rapid construction with pre-fabricated components, integration of recycled or beneficial reuse materials, and extended service life through reliable and durable design.20 However, additional improvements in sustainable project delivery are achievable through integration of material and design selection based upon life cycle analysis measurements; implementation of life cycle costing analysis versus lowest cost economics; use of innovative materials and technologies; and collaborative platforms during project design and construction.

Ms. Buffenbarger is the current Chairman of ACI’s Sustainable Concrete Committee. For more information, she can be contacted at [email protected].

Part II will appear in the next newsletter, Issue 77.

References

  1. United Nations Development Programme, “Paving the Way for Climate-Resilient Infrastructure: Guidance for Practitioners and Planners”, New York, New York, 2011;
  2. Biggs, C., Ryan, C. and Wiseman, J., Distributed Systems: A design model for sustainable and resilient infrastructure. Victorian Eco-Innovation Lab University of Melbourne, 2008.
  3. Rigaud, K.K. and Iqbal, F.Y., “Thematic Note 2: How the PPCR is Supporting Climate Resilient Infrastructure”, World Back Pilot Program for Climate Resilience Coordination Unit, October 31, 2011.
  4. Department for Environment, Food and Rural Affairs, Climate Resilient Infrastructure: Preparing for a Changing Climate, United Kingdom, 2011.
  5. National Research Council (US), Committee on Climate Change and US Transportation Research Board, Division on Earth and Life Studies; Transportation Research Board Special Report 290: Potential Impacts of Climate Change on US Transportation, Washington DC, 2008.
  6. Skinner, Jr., R.E., “Highway Design and Construction: The Innovation Challenge”, The Bridge, Vol. 38, No. 2, Summer 2008, pp. 5-12.
  7. American Association of State Highway and Transportation Officials, “Transportation Invest in Our Future – America’s Freight Challenge, May 2007.
  8. National Bridge Inventory. Federal Highway Administration. Web. 9 September 2014.
  9. Center for Environmental Excellence, American Association of Highway Engineers. Web. 7 September 2014.
  10. Transport Canada’s Departmental Sustainable Development Strategy 2013-2014 – Planning Update. Transport Canada. 26 February 2013. Web. 7 September 2014.
  11. Skalko, S. and Szoke, S., “High Performance Building Requirements for Sustainability”, Concrete Sustainability Conference, National Ready Mixed Concrete Association, 13-15 April 2010, Tempe, Arizona.
  12. U.S. Department of Transportation Center for Climate Change and Environmental Forecasting Strategic Plan 2006-2010. U.S. Department of Transportation. Web. 8 September 2014.
  13. Green, H., (2011), “Message from the National Institute of Building Sciences”, Journal of Advanced and High-Performance Materials, pp.16-21, p 5.
  14. Doyle, C., (2011), “Message from the U.S. Department of Homeland Security”, Journal of Advanced and High-Performance Materials, the National Institute of Building Sciences Advanced Materials Council, p 7.
  15. Buffenbarger, J. K., “Paving the Way to “Green”: Sustainable Solutions to Road Structures”, Powerpoint. Created April 15, 2009.
  16. Buffenbarger, J.K. “The Sustainable Highway: Implementation of Green Rating Systems within Transportation Infrastructure”, Powerpoint. Created August 24, 2010.
  17. Center for Environmental Excellence by AASHTO, Above and Beyond: The Environmental and Social Contributions of America’s Highway Programs, January 2008.
  18. Brown, J.W., “Eco-Logical: An Ecosystem Approach to Developing Infrastructure Projects”, U.S. Department of Transportation Research and Innovative Technology Administration, Cambridge, Massachusetts and Office of Project Development and Environmental Review Federal Highway Administration U.S. Department of Transportation, Washington, DC, April 2006.
  19. Litman, T. and Burwell, D., “Issues in Sustainable Transportation”, Int. J. Global Environmental Issues, Vol. 6, No. 4, 2006, pp. 331-347.
  20. Ahlborn, T., (2008) “Sustainability for the Concrete Bridge Engineering Community”, ASPRE, Winter, pp. 16-19.

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