America’s Aging Bridges: How Geosynthetics Can Support Urgent Repairs for a Stronger Future
The state of America’s bridges is sounding alarms across the nation. From the catastrophic collapse of the Francis Scott Key Bridge in Baltimore to the looming maintenance challenges of thousands of aging structures, it’s clear that our bridge infrastructure demands immediate action. According to a recent analysis by the Hearst Television Data Team, over 38,000 bridges in the U.S. are in poor condition, with an additional 241,715 rated as fair—teetering on the edge of deterioration. With the average bridge nearing 47 years old, close to its typical 50-year lifespan, the time to act is now. Fortunately, innovative solutions like geosynthetics from Carthage Mills offer a cost-effective, durable, and efficient way to address these challenges, helping to reinforce and extend the life of our nation’s bridges.
The Crumbling Reality of U.S. Bridges
The collapse of the Francis Scott Key Bridge, caused by a cargo ship collision, was a tragic wake-up call, claiming six lives and exposing the vulnerabilities of aging infrastructure. But this isn’t an isolated issue. The Black Hawk Bridge, connecting Iowa and Wisconsin, is another stark example. At 94 years old and in poor condition, it’s riddled with corrosion, section loss, and structural deficiencies that make repair unfeasible. As Jim Nelson, Director of Bridges and Structures for Iowa’s DOT, noted, the bridge’s “defects and deterioration” necessitate a full replacement—a $140 million project. Iowa alone has 22.8% of its bridges in poor condition, the highest in the nation, highlighting a widespread crisis.
Before and After of the Francis Scott Key Bridge Collapse in Baltimore MD, 2024 – Credit to WLWT (see references)
Bridges face relentless wear from environmental factors like winter weather, de-icing chemicals, and heavy traffic. Without consistent maintenance, small issues like cracks or corrosion can escalate into major structural failures. Former U.S. Secretary of Transportation Anthony Foxx emphasized that decades of deferred maintenance, compounded by funding uncertainties, have created a “huge backlog of bridges in disrepair.” The Hearst analysis reveals that while proactive maintenance can extend a bridge’s life significantly, many states lack the resources to act before conditions worsen. The result? A ticking time bomb of infrastructure challenges that threaten safety and economic stability.
Bridges and Geosynthetics: A Game-Changer for Bridge Infrastructure
Enter geosynthetics—a proven, innovative technology that can transform how we repair, reinforce, and build bridges. The Geosynthetic Reinforced Soil Integrated Bridge System (GRS-IBS), as outlined by the Federal Highway Administration (FHWA), offers a fast, cost-effective, and durable solution. Unlike traditional methods that rely on costly deep foundations or cast-in-place concrete, GRS-IBS uses layers of compacted granular fill and geosynthetic fabrics, such as those provided by Carthage Mills, to create stable, long-lasting bridge abutments and approaches.
Here’s how it works: GRS-IBS integrates three main components—the reinforced soil foundation, the abutment, and the approach—into a seamless, jointless system. The foundation is built with granular fill encapsulated by geotextile fabric, which enhances stability and prevents water infiltration. The abutment alternates layers of fill with closely spaced geosynthetic reinforcement, supporting the bridge directly without joints. This design eliminates the notorious “bump at the bridge” caused by differential settlement, ensuring a smoother, safer ride. Carthage Mills’ high-quality geotextiles and geogrids are ideal for these applications, offering tensile strength, durability, and soil confinement that enhance the composite behavior of the structure.
The FHWA’s research highlights that GRS-IBS can support bridge loads up to 25 ksf (kilopounds per square foot), far exceeding typical working loads of 4 ksf. With reinforcement spacing of 12 inches or less, the system creates a composite mass that resists lateral deformation, increases soil stiffness, and reduces creep over time. This makes it an excellent choice for both new bridge construction and retrofitting existing ones, particularly in areas with challenging soil conditions like loose granular or soft organic soils.
TOP 5 STATES WITH BRIDGES IN THE WORST CONDITION:
#5 Rhode Island – 16% of bridges in poor condition
#4 Maine – 16% of bridges in poor condition
#3 West Virginia – 19.5% of bridges in poor condition
#2 South Dakota – 21% of bridges in poor condition
#1 Iowa – 22.8% of bridges in poor condition- See References
Bridges and Geosynthetics – How Carthage Mills Can Make the Difference
Carthage Mills has been a trusted name in geosynthetics for decades, providing materials that meet the rigorous demands of infrastructure projects. Their geotextiles and geogrids are engineered for strength, durability, and ease of installation, making them perfect for GRS-IBS applications. Whether reinforcing a bridge abutment or stabilizing an approach, Carthage Mills’ products help extend the lifespan of bridges by:
- Enhancing Stability: Geosynthetics confine soil, reducing lateral movement and increasing load-bearing capacity, which is critical for aging bridges experiencing settlement issues.
- Reducing Maintenance Costs: By preventing issues like differential settlement and water infiltration, Carthage Mills’ materials minimize the need for frequent repairs, saving states millions over time.
- Accelerating Construction: GRS-IBS with Carthage Mills’ geosynthetics can be installed quickly, reducing project timelines and traffic disruptions compared to traditional methods.
- Ensuring Durability: The composite behavior of GRS, reinforced by Carthage Mills’ products, resists environmental stressors like corrosion and freeze-thaw cycles, ensuring long-term performance.
A Call to Action for Safer Bridges
The clock is ticking on America’s bridges. With thousands in poor or fair condition, proactive measures are essential to prevent further tragedies and economic disruptions. Investing in maintenance and innovative solutions like GRS-IBS can save lives, reduce costs, and strengthen our infrastructure for future generations. As Anthony Foxx aptly stated, “It’s much better from a lifecycle cost standpoint to preserve the good and fair bridges that we have and invest in proactive maintenance treatments.”
Carthage Mills stands ready to support this mission with industry-leading geosynthetics that make GRS-IBS a reality. By partnering with state DOTs, engineers, and contractors, Carthage Mills can help transform the way we maintain and build bridges, ensuring they remain safe, stable, and reliable for decades to come. Let’s act now—before another bridge becomes a headline for all the wrong reasons.
Sources: