Building bridges in a transforming industry
The cement industry is reducing its carbon footprint by gradually replacing traditional Portland cement with new, lower-carbon cement. This has implications for tile-adhesive manufacturers. Our colleagues in Burghausen have investigated how and why the formulation of carbon-reduced adhesives can be successful.
The cement industry is transforming. Under pressure to reduce CO2 emissions, producers are shifting away from traditional Portland cement (CEM I) and toward cement types with a reduced content of Portland clinker (CEM II – CEM V).
CO2 emissions in cement production
Portland clinker is a main driver of CO2 emissions in cement production. It is produced by heating crushed limestone and a mix of other additives to 1450 °C in a rotary kiln. The rotary kiln is the heart of the manufacturing process where raw materials are heated up and decarbonization of the limestone takes place through a chemical reaction referred to as calcination. This chemical process causes 60 to 65% of emissions in cement manufacturing (process emissions). The remainder of the CO2 emissions comes from the fuels used to heat the kiln (combustion emissions).1
These new cement types are typically optimized to provide excellent compressive strength, which is a key attribute for concrete production. And since over 80% of produced cement goes into concrete construction, the availability of Portland cement is declining and will continue to do so. In some European countries, CEM I has already been withdrawn from the market.
For tile-adhesive manufacturers, this presents new challenges. They are not primarily looking for compressive strength but for performance attributes, which so far have been best delivered by Portland cement. They now need to adapt to the new market reality and work with the cement types that are available. We recently conducted tests and adapted our portfolio of VINNAPAS® polymer binders to provide solutions for this new reality.
"Cement in transition" – an interview with our colleague Gustavo Soares, Global Segment Manager for Tile Adhesive Applications, dives deeper into the industry’s challenges. Read the whole interview here.
Types of cement according to EN 197-1
The German cement industry has set itself the goal of producing climate-neutral cement by 2050. The lion’s share of CO2 emissions in cement manufacturing is caused by clinker production. Therefore, reducing clinker consumption is one focus of the cement industry. Cement types and their composition are classified according to standard EN 197-1. CEM I, CEM II, and CEM III are mainly used for general construction, with CEM I being used in decreasing quantities.
CEM II cement in tile-adhesive formulations
The use of CEM II cements helps improve the carbon footprint of tile adhesives. Calculations show that emissions are reduced from around 402 grams of carbon dioxide equivalent per kilogram of C2TE tile adhesive to 376 grams when CEM II/A cement is used.
However, CEMII cements are typically produced to meet the needs of the concrete industry. They are not optimized for use in tile adhesives. When we tested different types of CEM II in a C2TE tile adhesive, we found that some properties were retained, some were even improved, but some were also negatively affected. Flexibility was even improved in a C2TE S1 formulation. However, two key properties were negatively affected: early strength development and tensile adhesion strength after immersion in water and freeze/thaw cycles.
Both problems result from reduced reactivity due to clinker reduction. Both can be successfully addressed by adjusting the formulation and selecting a specific grade of VINNAPAS® polymer powder. Our expert Klas Sorger, Technical Service Manager Europe, explains how and why in this video.
VINNAPAS® grades for tile adhesives with reduced carbon emissions
The animation illustrates how a reduced clinker content leads to reduced reactivity in the mortar. Adding a suitable VINNAPAS® E grade will compensate for this by forming polymer bridges. In particular, our advanced VINNAPAS® E vinyl acetate-ethylene grades with hydrophobic monomers in the VAE polymer chain are suitable for improving tensile bond strength after immersion in water.
Let’s formulate a more sustainable future. Together.
We are confident that the cement industry, as well as other partners in the value chain, will find ways to further reduce the carbon footprint of the construction industry. With our Technical Competence Centers around the world, we are well positioned to support this evolution.
Most of our VINNAPAS® grades are also available as eco grades. Eco grades are partially based on renewable resources in accordance with the mass balance approach. The carbon footprint can be reduced even further.
And just as our comprehensive VINNAPAS® portfolio makes it possible to use CEM II in high-performance tile adhesives without compromising performance, we will strive to be part of other more sustainable solutions for the future.
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