The Flawless Surface of High-Performance Floors: Self-Leveling Screeds
In modern construction projects, speed, aesthetics, and durability are indispensable elements. Self-leveling screeds are high-tech construction materials developed to create smooth and even floor surfaces, addressing these three needs simultaneously. However, one of the most critical challenges for these high-performance systems is shrinkage-induced cracks that occur during setting and drying. These cracks are not merely an aesthetic flaw; they also jeopardize the structural integrity and long-term performance of the floor. As Ekvator Kimya, we offer innovative solutions that enable construction chemical formulators to overcome this challenge: Shrinkage Reducing Admixtures (SRA).
The Science Behind Shrinkage and Crack Formation
Self-leveling screed formulations typically contain a high proportion of water and cement/binder to ensure fluidity. This inevitably leads to shrinkage during the drying process. Shrinkage is primarily examined in two stages:
- Plastic Shrinkage: Occurs when the mixture is still in a plastic state, and the rate of water evaporation from the surface exceeds the rate of water transport from within the material to the surface. This causes stresses on the surface and early-age cracks.
- Drying Shrinkage: A continuous process that occurs after the screed has hardened, due to the evaporation of water from the capillary pores of the cement paste. As water molecules evaporate, the surface tension of the water in the capillary pores creates an internal tension that pulls the pore walls towards each other. When this tension exceeds the tensile strength of the material, micro and macro cracks occur.
Self-leveling screeds applied in thin layers are particularly susceptible to evaporation and thus drying shrinkage due to their large surface areas.
The Solution: Role and Mechanism of Shrinkage Reducing Admixtures (SRA)
While traditional methods (curing, fiber reinforcement, etc.) can control shrinkage to some extent, they may be insufficient for high-performance and sensitive formulations. This is where Shrinkage Reducing Admixtures (SRA) come into play. SRAs are special molecules that chemically intervene in the fundamental cause of drying shrinkage.
The working mechanism of SRAs is based on reducing the surface tension of water in the capillary pores of the cement paste. When surface tension is reduced, the tensile force applied to the capillary walls as water evaporates is also significantly diminished. Consequently, the internal stresses causing shrinkage are minimized, and the risk of crack formation is eliminated. This ensures that the material remains much more dimensionally stable.
Ekvator Kimya's SRA Portfolio: For Formulation Excellence
Ekvator Kimya offers highly efficient SRA solutions for self-leveling screed manufacturers to achieve reliable results even in the most challenging projects. Our prominent products in the portfolio are designed to add value to your formulations:
- Peramin® SRA Series: Known for their high efficiency, these products effectively reduce shrinkage even at low dosages. They exhibit excellent compatibility with other admixtures such as superplasticizers, without negatively affecting the rheological properties and workability of the formulation. By maximizing dimensional stability, they minimize the risk of cracking even in the most sensitive applications.
- Curestar® SRA Series: This series offers a combination of performance and cost-effectiveness, making it ideal for a wide range of self-leveling screed formulations. While providing reliable shrinkage control, it grants manufacturers the flexibility to develop competitive and high-quality products.
Advantages of Using SRA in Formulations
Adding Peramin® or Curestar® SRA to your formulations not only prevents cracks but also provides a series of critical advantages:
- Improved Dimensional Stability: The shrinkage of the screed during drying is significantly reduced, leading to less internal stress and a more stable structure.
- Superior Surface Quality: The prevention of cracks and curling ensures the achievement of aesthetically flawless, smooth surfaces.
- Increased Durability: The inhibition of micro-cracks enhances the mechanical strength and abrasion resistance of the material, extending the service life of the floor.
- Larger Jointless Areas: Thanks to shrinkage control, it allows for covering larger areas without the need for control joints, offering a monolithic and aesthetic appearance.
- Reliability and Performance: Guarantees the performance of the formulation even under various site conditions (low humidity, air currents, etc.).
Conclusion: Crack-Free Formulations for the Floors of the Future
Shrinkage-induced cracks in self-leveling screeds can be a significant headache for formulators. However, with the right technology and chemical admixtures, this problem can be entirely prevented. Ekvator Kimya's Peramin® and Curestar® SRA series intervene in the fundamental mechanism of drying shrinkage, empowering construction chemical manufacturers to develop dimensionally stable, durable, and aesthetically perfect floor coverings. To elevate your formulations and leave shrinkage cracks in the past, contact Ekvator Kimya's expert technical team.
