The Transition to Type IL Cement
The team at Sakrete is constantly looking for ways to reduce our environmental impact through new technologies, formulations and processes. One of the most promising directions that is being implemented today is the transition from Portland Cement – Type I/II to a newer, more sustainable formulation called Portland-Limestone Cement – Type IL.
What is Portland Cement?
All Portland cements are a blend of minerals that are derived from heating limestone (calcium carbonate) and clay/shale together at very high temperatures. Depending on the properties of the final mixture, the cement is classified into one of several categories based on reactivity, particle size, and/or chemical composition.
Typical Portland cement is very environmentally burdensome because of the high temperatures required (that requires burning of fossil fuels) as well as the CO2 that is given off from the limestone when it is decomposed during the heating process.
Why We’re Transitioning to Type IL
Cement manufacturing accounts for ~5 – 8% of global CO2 emissions and because of that, cement manufacturers are trying to reduce the environmental impacts by making a cement that is primarily composed of typical Portland cement but also has some amount of unburned limestone that acts as a “filler.” This reduces the amount of material that needs to be heated and reduces the amount of CO2 given off by the decomposing limestone. The term for this cement is Type IL.
For additional technical details, check out the Portland Cement Association’s page on Portland-Limestone Cement.
Impacts on Concrete Products
The Sakrete Technical Team has done extensive testing on Portland-Limestone Cement and have not seen any data suggesting that it has a negative impact on our products. In fact, in many of our tests, we have seen an increase in strength due to limestone’s tendency to densify the cement matrix.
ASTM designations on Portland cement bags will be updated as a different ASTM standard governs Type IL – ASTM C595 is the standard for Type IL, whereas ASTM C150 is the standard for legacy Type I/II cement. Bags and TDS documents for concrete/mortar mixes will likely not change at all due to this switch – and you shouldn’t expect any changes in the workability, strength or performance of any Sakrete product.
A Commitment to Sustainability
The transition to Portland-Limestone – Type IL cement is just one way that Sakrete is working to make concrete more sustainable. Stay tuned for more enhancements coming soon!
As always, give our Technical Team a call with any questions you might have about Type IL Cement – or any other topic – at 866-SAKRETE.