Portland Limestone Cement – Helping the Environment


It is not your father’s cement.

Manufacturers have reformatted the way they make cement to help protect the environment and reduce their carbon footprint. Portland Cement has gone away, replaced by Portland Limestone Cement (PLC). The impact of this change on the cement overlay market will be huge.

Knowing that this change was coming, Durável spent extensive time in the lab researching PLC and testing formulas. PLC doesn’t significantly affect standard ready-mix concrete but the changes to thin overlays are profound.

Broom Concrete Overlay 
Stamp Concrete Overlay 
Decorative Concrete Overlay ( Sprayable)
Thin Concrete Overlay (Micro-Topping)

 You cannot simply replace Portland with PLC in your old overlay formula without having problems. Durável has modified its concrete overlay formulas to take full advantage of the enhanced performance available from PLC and to eliminate the associated problems.

With these enhanced formulas you will have the same – or even longer – open time. Durável overlays have a creamier feel under your trowel. Plus, using PLC has added about ten percent to our compressive strength, flexural and tensile strength, and increased abrasion resistance.

You will find these new PLC formulas across the entire Durável lineup of concrete overlay and repair mortars. An additional improvement is that Durável is now packaged in weather-resistant plastic bags which are stronger than conventional paper sacks and ready to survive occasional rain. Our plastic bags also help protect the environment as they are fully recyclable!

Reduced Carbon Emissions: The production of PLC concrete requires less energy and emits fewer carbon dioxide (CO2) emissions compared to traditional concrete. This helps to reduce the carbon footprint of construction projects and contributes to a more sustainable environment.

Conservation of Natural Resources: PLC concrete incorporates pozzolanic materials, such as fly ash or silica fume, which are byproducts of other industrial processes. By using these materials, PLC concrete helps to reduce the demand for virgin raw materials, such as limestone and clay, which are typically used in the production of traditional concrete.[1] Waste Reduction, the use of pozzolanic materials in PLC concrete also helps to reduce waste.

Often when products are created for a greener environment they end up being a compromise and not nearly as good as the original. Adding limestone to cement has been proven to improve its quality through numerous real-life tests.

Limestone has been found to make the cement just as good, and in some cases, even better. This is because of the fine texture of limestone, which aids in better mixing and ultimately results in a stronger cement. This is because the limestone is extremely fine and helps the cement mix better and become stronger.

However, there are also some disadvantages to consider. Adding class F fly ash to concrete decreased its strength after 28 days of curing. The strength decreased significantly as more fly ash was added. Pozzolins used in Durável products are selected from those that increase workability and the resulting strength of the coating.

By incorporating industrial byproducts into the concrete mix, PLC concrete provides a beneficial use for materials that would otherwise be disposed of as waste. Improved Air Quality: The production of PLC concrete generates less dust and particulate matter compared to traditional concrete. This helps to improve air quality in and around construction sites, creating a healthier environment for workers and nearby communities.[4]

Industry Sources :

[1] https://en.wikipedia.org/wiki/Limestone_Calcined_Clay_Cement

[2] https://www.specifyconcrete.org/blog/portland-limestone-cement-makes-concrete-greener

[3] Quora.com

[4] https://www.cement.org/sustainability/portland-limestone-cement

PLC Overlays