Insights on Portland Limestone Cement & Concrete Mixtures

Abstract: In recent years, cement companies nationwide have transitioned from producing primarily ASTM C150 Type I/II cement to predominantly ASTM C595 Type IL, or Portland Limestone Cement (PLC). While these cement types are very similar, there are some differences that impact the development of mix designs and concrete production. This presentation examines sources of variability in production of cement and how varied cement characteristics influence the fresh and hardened properties of concrete. While this product has only been introduced to many markets within the last few years, PLC has been successfully used in pavements in Colorado for over 15 years. With the widespread adoption of PLC, it is essential to investigate the correlation between this newer cement type and potential performance issues. Drawing from a significant history of PLC use in concrete pavements across DOT, local agency, and airfield projects, this session emphasizes the importance of re-evaluating mix designs to ensure compatibility among material combinations. It will also outline effective strategies for developing and batching concrete mixes when incorporating PLC and other new material combinations. Attendees will gain valuable insights into optimizing concrete performance, addressing potential challenges, and enhancing the durability and sustainability of pavements in response to evolving industry practices.