Because of market and government demands to reduce greenhouse gas emissions (carbon dioxide), the cement industry is transitioning to increased use of portland limestone cement (PLC) Type IL in an effort to become more carbon neutral. The Type 1L cement is in accordance with ASTM C595/AASHTO M240 and is a blend of 90% traditional cement and 10% limestone.
Many NPCA members already are using PLC Type 1L in production facilities. Those who are not will be doing so soon as PLC Type 1L becomes more commonplace from suppliers who provide Type I or II cement. As the cement industry works toward carbon neutrality, it will transition away from supplying Type I or II cement to Type 1L only.
For more information on PLC Type 1L, click here to read a recent NPCA article on the topic.
.P. “Doc” Watson, FACI, FICRI says
The use of added limestone in Portland cement has a history well before the designation IL. It is beneficial that being recognized and clearly identified is official. Tracking properties and performance are improving, leading to design and methods improvements.