Recent portland-limestone cement (PLC) approval by the Arizona and Maryland Departments of Transportation, plus the Vermont Agency of Transportation, brings the total state authorities accepting the use of the material for transportation projects to 44.
Since its introduction in the U.S., more than 6 million metric tons of PLC has been used in concrete throughout the country.
Most commonly designated as Type IL cement and produced to meet ASTM C595, Standard Specification for Blended Hydraulic Cements, PLC allows for 5% to 15% of ground, uncalcined (unfired) limestone to be blended and/or interground with clinker and other ingredients. The resultant cement offers similar performance to traditional portland cement but with a carbon footprint up to 10% lower.
Use of PLC for transportation and all other concrete applications has been steadily increasing since October 2020, when the Portland Cement Association (PCA) formally introduced www.greenercement.com to raise awareness and educate specifiers, builders and other users about the benefits and use of this lower carbon cement.
Widespread acceptance of PLC marks a significant step to reducing the carbon footprint of concrete construction and advancing the goals laid out in the PCA Roadmap to Carbon Neutrality.