California’s agency for highways and freeways, Caltrans, has approved the use of Portland limestone cement (PLC) in the building of its highway system. The agency hopes to reduce the carbon footprint of the US state’s transportation system by as much as 10 per cent annually when compared with ordinary Portland cement (OPC).

According to Caltrans, the agency used 325,000t of cement in 2017 to upgrade California’s highway system. The shift to low-carbon cement can potentially reduce CO2 emissions by 28,000tpa.

The approval followed Caltrans-funded research by Oregon State University’s Jason Weiss, professor of civil and construction engineering and the Miles Lowell and Margaret Watt Edwards Distinguished Chair in Engineering.