There’s a little-known secret about recycling—it often doesn’t work, at least not in the way we usually think. According to the Environmental Protection Agency (EPA), more than 7.55 million tons of glass intended for recycling end up in landfills each year. This represents almost all the glass waste in the United States. The main issue with recycled glass is contamination from paper, plastic, and metal, which renders the glass unusable for making new bottles.

In response, the New York State Department of Transportation (NYSDOT) and the city of Binghamton are reimagining this problem. They are innovating to transform our infrastructure and meet the pressing transportation challenges of today.

The Problem

Cement manufacturing is responsible for 7 percent of global CO2 emissions, encountering significant barriers in its path to decarbonization. These include high capital costs, unproven technologies, and a lack of local adoption. As environmental product declarations (EPDs) become more prominent in Federal and State funding opportunities, agencies must consider how their materials affect performance and sustainability when targeting funding.
For instance, the “New York State Buy Clean Concrete Guidelines,” effective starting in 2025, will limit the global warming potential (GWP) of all concrete purchased with State funding. This includes infrastructure projects funded through NYSDOT.

The Role of SCMs

According to the Department of Energy’s Industrial Decarbonization Roadmap, using novel supplementary cementitious materials (SCMs) is one of the most effective strategies to reduce the GWP in concrete mixes. These materials harness the pozzolanic reaction found in Roman concrete to replace a portion of cement and enhance performance.

The transportation industry has long been familiar with SCMs, having pioneered the use of fly ash from coal power plants and slag from steel foundries. However, with the decline of these industries—highlighted by the closure of New York’s last coal power plant in 2020 and similar closures anticipated in New England by 2025 and 2028—the search for alternative SCMs has intensified.

Glass, rich in silica, has been identified as a superior SCM compared to fly ash and slag. Research by scientists from Eindhoven University of Technology, Ömer Halisdemir University, and the University of New South Wales has demonstrated that glass SCMs enhance compressive strength while avoiding the detrimental alkali–silica reaction. With ASTM C1866, Standard Specification for Ground-Glass Pozzolan for Use in Concrete, established in 2020, glass SCMs were technically viable but economically unfeasible until recent advancements in glass processing technology and the scale-up of production facilities. These developments have made glass SCMs cost-competitive with traditional materials, especially in regions logistically isolated from fly ash and slag suppliers.

Small-Town Innovations 

In 2022, the city of Binghamton in New York began incorporating glass SCMs into all curb and sidewalk projects, reducing the cement content by 20 percent and cutting more than 1,000 pounds (453.6 kilograms) of CO2 emissions per ready-mix concrete truck. These $1.7 million upgrades brought advanced, low-carbon concrete solutions to the city, including disadvantaged communities on the east side of Binghamton.

The initiative aimed to harness purpose-driven innovation to tackle current challenges in the transportation system while addressing a major waste issue. City engineers revised mix designs and secured support from the local ready-mix producer and contractor.

The project proved to be a resounding success, validating the use of glass SCMs in real-world applications. It demonstrated how strategic partnerships and adherence to existing standards can rapidly decarbonize transportation infrastructure. Supported by all levels of the industry, these projects continued into 2023 and 2024, with plans to maintain the use of glass SCMs in all future projects. This local initiative not only bolstered supply chain resilience and economic strength but also created three new jobs.

As a significant step in climate action, Binghamton’s efforts drew national attention from the EPA, capturing the interest of local NYSDOT members and setting a precedent for other municipalities across the Nation.

From Bottles to Bridge Sidewalks

NYSDOT developed Standard 711-15, Miscellaneous Supplementary Cementitious Materials, and initiated testing of glass SCMs. This development is part of NYSDOT’s shift toward performance-engineered mixtures, which offer producers greater flexibility in material choices and foster grassroots innovation at the local level.

Building on Binghamton’s success, NYSDOT specified glass SCMs in a Whitney Point, NY, bridge project, mandating its use for all curb and sidewalk placements. The $21.2 million project constructs 1.5 miles (2.41 kilometers) of new ADA-compliant sidewalks along both sides of U.S. Route 11 and installs new crosswalks at the Whitney Point Middle School and Broome County Fairgrounds.

As research aligns with policy to foster breakthroughs and develop economic infrastructure for all communities, NYSDOT is championing new mix designs that incorporate low-carbon materials, positioning itself at the forefront of industry innovation. The Whitney Point bridge project began in May 2024 and marks one of the largest glass SCM deployments in the United States.

The Future of Concrete for Transportation Infrastructure

The collaborative efforts of NYSDOT, the city of Binghamton, partnering universities, and private enterprises demonstrate how State transportation agencies and the Federal Highway Administration can build resilient supply chains, implement cross-cutting solutions, and enhance system reliability. These initiatives strengthen local economies and elevate global competitiveness. The future of concrete in transportation will harness new materials to construct the systems the Nation will rely on for years to come. While there may not be a single solution to the challenges of climate change and material shortages in the concrete industry, New York’s approach offers a blueprint for how collaboration can lay the groundwork for a more robust future.

Samuel Lamuraglia is an undergraduate at State University of New York at Binghamton. Samuel is currently studying environmental studies and will graduate in 2026.