ASTM International has published ASTM C595-12, Standard Specification for Blended Hydraulic Cements. The recent revision defines requirements for a new cement type: Type IL, portland-limestone blended cement, which includes more than 5% and up to 15% limestone as an ingredient. This technology has the potential to reduce environmental impact of cement production by about 10% while maintaining performance characteristics concrete producers are familiar with. Similar cements have been used in Europe and other places around the world for several decades and have demonstrated the performance and durability expected in concrete products.

The revision represents the results of several years of cooperative effort by the Joint AASHTO-ASTM Harmonization Task Group, and was endorsed by the Portland Cement Association's (PCA) Product Standards and Technology Committee and Standards Subcommittee. Similar requirements have been approved by AASHTO’s Subcommittee on Materials for AASHTO M240. The update to M240 is scheduled to be published next month.

For the most recent editions of the specifications, please visit the following Web sites:

AASHTO: https://bookstore.transportation.org/