WACKER’s Solutions to Help Tile Adhesive Manufacturers Transition to CEM II Cements
The construction industry is facing increasing pressure to reduce its carbon footprint, particularly in the production of tile adhesives. Manufacturers of dry-mix mortars, especially those using Portland cement (CEM I), are grappling with the challenge of adapting their formulations to meet sustainability goals.
To address this, the cement industry is transitioning to lower-carbon alternatives like Portland composite cements (CEM II). WACKER, a global leader in specialty chemicals and formulations, is helping dry-mix mortar manufacturers navigate this transition by offering its innovative VINNAPAS® dispersible polymer powders, which enable the creation of high-performance formulations using CEM II cements. At the upcoming 2025 European Coatings Show in Nuremberg, Germany, WACKER will showcase a range of products designed to improve the properties of construction materials while minimizing environmental impact.
The Cement Industry’s Role in CO2 Emissions
The cement industry is a significant contributor to global CO2 emissions, responsible for approximately 8% of the world’s total emissions. As one of the most energy- and emissions-intensive sectors, the cement industry has recognized the urgent need for change. To mitigate its environmental impact, many companies in the industry have begun producing Portland composite cements (CEM II) that contain a lower proportion of the traditional Portland clinker. This change reduces the carbon footprint of cement production by utilizing alternative materials like fly ash, slag, and natural pozzolans.
CEM I, the traditional form of Portland cement, has been a key ingredient in tile adhesives for years. However, as CEM II cements gain traction due to their lower environmental impact, tile adhesive manufacturers must adjust their formulations to incorporate these new types of cement while maintaining or improving the performance of their products. This is particularly important as several industrialized countries, including those in Europe, are aiming to produce climate-neutral cement by 2050.
Adapting Tile Adhesives for CEM II Cements
Tile adhesives are primarily composed of cement, with CEM I being the traditional binder used. As CEM I becomes less available, manufacturers must switch to alternative binders like CEM II. However, replacing CEM I with CEM II presents challenges, particularly in maintaining the performance characteristics of the adhesive. To investigate this, WACKER conducted a series of tests to determine how replacing CEM I with CEM II affects the properties of tile adhesives.
WACKER’s study used a reference tile adhesive classified as C2TE under European standard EN 12004. This classification indicates that the adhesive has high strength (C), high resistance to vertical slip (T), and an open time of at least 30 minutes (E). The research involved replacing the CEM I content in the reference sample with four different CEM II formulations to assess whether the new adhesives would meet the performance criteria.
Key Findings from WACKER’s Testing
The results of WACKER’s tests showed that, in general, most of the properties of the tile adhesives remained stable when CEM I was replaced by CEM II. Properties such as density, workability, resistance to vertical slip, and wetting capability all met the requirements specified in the standard. However, two critical properties were adversely affected by the switch to CEM II: the tensile adhesion strength following immersion in water and the early strength.
In comparison to the reference sample, all CEM II formulations tested exhibited lower initial tensile adhesion strength and reduced adhesion strength after exposure to elevated temperatures and freeze-thaw conditions. Most notably, the adhesives formulated with CEM II failed to meet the required tensile adhesion strength of 1 N/mm² following immersion in water, a crucial requirement for C2-rated adhesives.
Enhancing Performance with VINNAPAS® Dispersible Polymer Powders
To address the challenges posed by the substitution of CEM I with CEM II, WACKER offers a solution through its VINNAPAS® range of dispersible polymer powders. These polymer-modified adhesives can significantly improve the tensile adhesion strength of CEM II-based tile adhesives, particularly after immersion in water.
By incorporating special terpolymers into the vinyl acetate-ethylene (VAE) copolymer backbone, which includes water-repellent monomers, WACKER has developed a technology that improves the water resistance of tile adhesives. In tests with VINNAPAS® 8118 E, 8620 E, and 7220 E dispersible polymer powders, the tensile adhesion strength following immersion in water was markedly improved, ensuring that the tile adhesives met the C2 requirement specified in the European standard.
Conclusion: Achieving Sustainability Without Compromising Performance
The transition from CEM I to CEM II cements is a necessary step for the construction industry to reduce its environmental impact. While CEM II cements offer a more sustainable alternative to CEM I, their use in tile adhesives presents challenges that must be addressed to maintain product performance.
WACKER’s VINNAPAS® dispersible polymer powders provide an effective solution to these challenges. By modifying the composition of tile adhesives, manufacturers can achieve the same high-performance characteristics with CEM II cements as they did with CEM I. Furthermore, this transition helps manufacturers reduce the carbon footprint of their products, contributing to the global effort to mitigate climate change.
At the 2025 European Coatings Show, WACKER will showcase its portfolio of products designed to enhance the performance and sustainability of construction materials. Through its commitment to innovation and sustainability, WACKER continues to support the industry in creating high-quality, eco-friendly products that meet the evolving needs of both manufacturers and consumers.
Visit also our website at Here for you: at ECS 2025!
