Cement & Concrete Basics FAQs


What is portland-limestone cement?

Portland-limestone cement (also called Type IL cement) is relatively new to the U.S. market. It is a type of blended hydraulic cement that contains between 5 and 15 percent limestone by mass. Cements with significant amounts of limestone as an ingredient have been used in Europe for several decades and are popular there. They are also in common use in many other countries around the world. Portland-limestone cements provide similar performance to portland cements in many applications, but have a reduced environmental impact:  less CO2 is generated and less energy is used per ton of cement as the limestone ingredient is not pyroprocessed like the clinker it replaces. This is making portland-limestone cements a popular choice for architects and engineers looking to construct more sustainable concrete structures. Requirements for portland-limestone cement are defined in ASTM C595 or AASHTO M 240.  More information on portland-limestone cements can be found in PCA’s publication:  State-of-the-Art Report on Use of Limestone in Cements at Levels of up to 15% SN3148.