Three new state Departments of Transportation in the USA have approved the use of Portland-limestone cement (PLC). The addition of Maryland, Arizona and Vermont means that a total of 44 states now accept PLC, according to the Portland Cement Association (PCA). Designed for the same uses at traditional Portland cements, PLC has been gaining in popularity for transportation and other concrete applications since late 2020.  

According to PR Newswire, since it was introduced in the US, more than 6Mt of PLC has been used across the country following heightened awareness of its ability to reduce the carbon footprint of concrete construction and align with the goals of the PCA Roadmap to Carbon Neutrality.

Allowing for 5-15 per cent of uncalcined limestone in its mix, PLC offers a similar performance to traditional Portland cements but with 10 per cent lower CO2. The same doses of supplementary cementitious materials (SCMs), such as fly ash and slag, can be used in its mix, as well as chemical admixtures, making the use of PLC, commonly designated as Type IL cement, an easy transition with simple modifications to existing specifications.