Portland Limestone Cement

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MCA has been working with MDOT on guidance documents and a special provision regarding the cement industry's production switch to ASTM C595 Type 1L cement, from the current standard ASTM C150 Type 1 (general use). We understand that many cement producers are in the process of switching over now, and MDOT has just issued the following documents that were jointly-developed with MCA input and guidance:



The intent of the guidance document is to ensure that cement producers have submitted their test data directly to Construction Field Services at MDOT, so that their Type 1L cement is on the approved products list.
The special provision outlines requirements that concrete producers (ready-mix companies and concrete pavers with portable plants) will have to follow for existing projects that are continuing to place concrete now, or will re-start in the spring after the winter break, and will require substitution of the new cement type into existing job mix formulas (JMFs) that are approved for use for one more year.
Quick Facts about Type 1L Cement:
  • MDOT has allowed Type 1L cement to be used in concrete since 2014, but the product has not been produced in significant quantities prior to now.
  • Type 1L is often referred to as "portland-limestone cement," or PLC
  • Cement companies typically formulate Type 1L to perform almost exactly like their Type 1.
  • Type 1L allows up to 15% interground limestone, whereas Type 1 has allowed up to 5% for many years now.
  • Most Type 1L cements result in an approximate 10% reduction in carbon production vs. the standard Type 1.
  • Other owner/engineer specifications will have to be modified to allow ASTM C595 Type 1L cement instead of the commonly specified ASTM C150 Type 1.
For more information on Type 1L cement in general:


Portland-limestone cement, or PLC, is engineered with a higher limestone content than portland cement to reduce the carbon footprint of concrete by about 10%. It performs just like the cement you’re used to using, resulting in the same concrete you’re used to having. The same specifications, the same mix design, now with a better carbon profile.

Concrete is everywhere. In fact, other than water, it’s the most-used material on the planet, representing about 50% of all manmade materials (by mass). It’s a versatile, economical construction material that is the basis for everything we build. Foundations. Buildings. Roads. Water and waste storage and delivery structures. Modern society is possible thanks to the versatility and widespread
availability of concrete.

Because society places so much concrete each year, even small changes to its formulation can have dramatic effects on the construction industry’s annual carbon footprint. Modifying a concrete mix design to replace higher carbon materials with lower carbon ingredients is an effective strategy. Portland-limestone cement offers an easy way for concrete producers to accomplish this, much like fly ash and slag cement have done for decades. And concrete mixes designed with PLCs are compatible with all supplementary cementing materials (SCMs), so when you substitute PLC for ordinary portland cement, you can continue to use all the other materials you use to make concrete for an even
greater reduction in carbon footprint.


Almost anywhere you use ordinary portland cement, you can use PLC instead. In the U.S., PLCs have an established track record for transportation infrastructure. Many states have been placing PLC concrete pavements for more than a decade – with good results. From highways to driveways, PLC performs just as well in heavy-duty pavements as it does for residential flatwork. And it’s appropriate for bridge applications, too, from top to bottom, everything from the deck down to the foundation, even including geotechnical work. For buildings, PLC concrete is a natural fit for structural members of any type or size, and it’s also great for exterior finishes and hardscaping. Architects and other designers who are tasked with meeting goals put forth by green rating systems or codes will find PLC an especially useful approach to help them achieve a lower carbon footprint for any project.


To help with the transition to more environmentally friendly concrete, cement manufacturers understand that the switch to PLC must be simple. By optimizing PLCs, they have made it easy for specifiers, producers, and installers to use them. PLC can be swapped in for portland cement at a 1:1 replacement level. This is a big help to ready-mix producers, who can continue operations using their well-established systems with a minimal amount of disruption. In most cases, all that is needed for maintaining fresh concrete behavior is the typical tweaking of proportions or admixtures, similar to changing from one source of cement to another. Anyone who knows how to work with cement and concrete knows how to work with PLC concrete.

View additional PLC Resources from PCA:




PCA: State-of-the-Art Report on  Use of Limestone in Cements at Levels of up to 15%

PCA REPORT: Sulfate Resistance of Mortar and Concrete Produced  with Portland-Limestone Cement and Supplementary Cementing Materials:  Recommendation for ASTM C595/AASHTO M 240