PORTLAND, Ore. (KOIN) — With concrete used throughout the city of Portland, city staff and leaders are re-thinking how concrete usage impacts the city’s carbon footprint.
According to an announcement by the city, chief engineers from Portland’s infrastructure bureaus approved recommendations to add specific concrete requirements for all city construction projects.
The recommendation is apart of Portland’s commitment to climate action and climate leadership, added the press release.
“Most of us don’t think much about the concrete beneath our feet,” said Stacey Foreman, who leads the project as the city’s sustainable procurement program manager. “As the most widely used building material in the world, it has a significant environmental impact. Portland is a leader in establishing these thresholds and in our approach of bringing multiple stakeholders together to develop them.”
The city explained that the largest component of concrete is cement. This means cement production alone generates 8% of global greenhouse gas emissions, according to the announcement.
In addition, the city said the lower-carbon mixes can be designed to perform as well as, or better, than conventional concrete, and are competitive in cost.
“When considering all city projects that use concrete, the annual reduction is significant. The city uses concrete for a high volume of projects, including sidewalks and ADA ramps, bicycle and pedestrian paths, fire hydrant pads, retaining walls for parks, and large infrastructure projects such as the Water Bureau’s Bull Run filtration facility and the Bureau of Environmental Services’ wastewater and stormwater infrastructure,” said the press release. “By adopting higher sustainability standards for concrete, bureaus will accelerate their use of concrete that is durable and that has been manufactured with lower climate impacts.”
The announcement added, “This change is a win for city bureaus, the environment and everyone who calls Portland home.”
In January, the new city standards will take effect. However, projects are already underway that use low-carbon concrete.
This includes the Environmental Services’ large-scale sewer improvement projects, such as the NW Thurman Street Reconstruction Project and the Downtown-Old Town Sewer Repair Program.
The city says curb ramps, the Washington Park Reservoir and the new Gabriel Park playground include this new material.
According to the announcement, the goal is to accelerate the city’s use of low-carbon concrete, and create a framework for a consistent, trackable and enforceable low-carbon standard.
“Implementing these threshold requirements will result in a range of 3 to 35% reduction in greenhouse gas emissions over historically used concrete mixes. For example, for a large project like a new water reservoir, a 19% reduction in concrete-embodied carbon represents a savings of approximately 3.5 million kg-CO2e (carbon-dioxide equivalent),” explained the city. “This would be the equivalent of removing 754 gasoline-powered cars off the road or the amount of carbon sequestered by 4,142 acres of U.S. forests (approximately three times the size of Forest Park) for one year.”