A quarter of the country’s bridges are aging, having been constructed before the 1960s. High temperatures and increased floods due to climate change are speeding up their aging and making them more fragile.
The New York Times article showed examples of how scorching temperatures and severe floods could damage bridges in the United States.
The high temperature in July, reaching 95°F (35°C), caused the bridge connecting the Bronx and Manhattan to become stuck in an open position due to the heat expansion of the steel. All lanes on both sides of the bridge were temporarily closed for almost four hours.
Surging flood waters after days of heavy rains collapsed a railroad bridge between Iowa and South Dakota on 24 July. That same day, temperatures also rose to 100°F (37.7°C).
In Maine, the bridge pavement along Lincoln Street in Lewiston buckled, causing authorities to close it for a few hours for repair. Department of Transportation experts inspected the bridge and found that its concrete surface had separated from the concrete bridge deck, though there appeared to be no damage.
Paul Chinowsky, a professor of civil engineering at the University of Colorado Boulder, researches the effects of climate change on infrastructure and warns of the risk of bridge damage. He notes that extreme spikes in heat linked to climate change increase the swelling of bridge joints and make it happen more frequently.
These bridges were built decades ago using materials not designed to withstand the sharp temperature swings, causing them to swell and contract and weakening them. “It’s getting so hot that the pieces that hold the concrete and steel, those bridges can literally fall apart like Tinkertoys,” Dr. Chinowsky said.
The article notes that as 2023 has been declared the hottest year on record, the country’s critical infrastructure, like roads and runways, has been impacted by severe temperatures, and bridges face particular risks. Executive director of the American Association of State Highway and Transportation Officials says that scientists, engineers, and government agencies are only beginning to develop standards for building climate-resilient bridges.
Colorado was the first state to consider climate change effects when it planned its infrastructure in 2018 after a 2013 flood caused several hundreds of millions of dollars in damages.
Dr Hussam Mahmoud, a civil engineer and professor at Colorado State University, explained how heat can permanently damage bridges. Extreme heat spikes linked to climate change can expand the bridge’s joints. These fork-teeth expansion joints are embedded into steel and pavement to accommodate swelling and contraction caused by temperature changes.
Still, extreme spikes in heat linked to climate change can increase swelling and make them more frequent, and when this happens, the steel can deform, crack, and let moisture in, causing it to rust.
In bridges, the purpose of expansion joints is to accommodate the natural movements of bridges caused by temperature fluctuations and traffic loads. Without expansion joints, bridges would be susceptible to stress, cracking, and structural damage (Tank, 2024).
Due to climate change, bridges are now exposed to a wide range of temperatures, from freezing winter to scorching summer, causing the bridge material to either contract or expand. Expansion joints enable the bridge to expand and contract freely, reducing the strain on the structure and contributing to its overall durability.
Climate change is causing more rapid shifts between extreme heat and cold, says Royce Floyd, a professor of engineering at the University of Oklahoma. He said that this seesawing of temperatures could damage infrastructure, causing the pavement to buckle or crack or even pushing steel out of alignment, which has happened to at least three significant bridges in Oklahoma in recent years.
Although these bridges have now been repaired, it is crucial to consider the findings of studies that show the impact of climate change on infrastructure. “If you don’t plan for climate change, then you’re going to end up with the same problems again,” Floyd said.
Sources:
Davenport, C. (2024, 2 September). Climate Change Can Cause Bridges to ‘Fall Apart Like Tinkertoys,’ Experts Say. The New York Times. Retrieved from https://www.nytimes.com/2024/09/02/climate/climate-change-bridges.html
Tank, N. (2024). Exploring the Importance of Bridge Expansion Joints: How They Enhance Durability and Safety. Concretefunda. Retrieved from https://www.linkedin.com/pulse/exploring-importance-bridge-expansion-joints-how-enhance-nitesh-tank-2yzcf/
Climate change could shorten the life span of U.S. bridges. (2024, 29 February). Yale Climate Connections. Retrieved from https://yaleclimateconnections.org/2024/02/climate-change-could-shorten-the-life-span-of-u-s-bridges/
Third Avenue Bridge reopens to traffic after getting stuck halfway due to heat. (2024, 9 July). Eyewitness News. Retrieved from https://abc7ny.com/post/avenue-bridge-connecting-bronx-manhattan-stuck-open-position/15043550/
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