Factors that Affect Sealer Performance on Concrete10 January 2020
Sealers are an important part of protecting concrete against surface damage, corrosion, and staining. They work by either blocking the pores in the concrete to prevent the ingress of water and water-soluble salts or by forming a polymeric barrier that prevents such materials from passing through to the substrate.
On the other hand, concrete is a highly complex substrate, comprising mineral aggregates and fillers like sand bound together in a crystalline, inorganic matrix based on hydrated calcium and aluminum salts. They are porous – containing many natural air voids as well as capillary pores created during the release of water during setting and cure. The exact nature of the concrete and concrete surface will vary, depending on the supplier and local raw materials, although it is essentially a porous, mineral substrate for the sealers.
Below are several factors that affect sealer performance on concrete.
Penetrating sealers contain reactive species, such as silanes, siliconates, and silicates that can enter the concrete matrix and react with minerals present to block the pores and create a hydrophobic and oleophobic barrier. Penetrating sealers have excellent durability but do not change or enhance the surface appearance of the concrete surface. They can also make further treatment of concrete difficult.
Topical sealers are coatings that form a polymeric film and barrier at the concrete surface. They are prepared using many different chemicals. This includes acrylic, epoxy, and polyurethane binders. Topical sealers may not last as long as penetrating sealers, but they can enhance and decorate the concrete surface and prepare it for additional treatment. Sealers are typically low viscosity coatings and contain either solvent or water as a diluter.
Solvent-based sealers are claimed to give better performance than water-based sealers, although it is acknowledged that the performance of water-based sealers is improving. One explanation often cited for the improved performance is that solvent-based sealers can better penetrate the concrete surface, providing some pore blocking and developing enhanced adhesion through mechanical interlocking. The improved adhesion is also cited as evidence for the improved penetration into the concrete, but in practice, there has been little research on the actual penetration of the sealer into the concrete.
Solvent-based sealers give a more glossy, wet-look finish, whereas water-based sealers often give a more natural-looking appearance. Many states now restrict the use and sale of solvent-based sealers for environmental, health, and safety reasons.
Know more about sealer performance on concrete from Auseal-Curite. We have been in business in the Dandenong region of Melbourne for many years, specialising in developing and manufacturing a wide range of unique coatings and decorative surfaces for concrete floors. Our product range covers a number of different types of coatings, with some ideal for interior sealed coatings in warehouse structures, whilst others have been formulated to improve the appearance and wearing properties of domestic driveways.
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