The Masterbuilder – June 2007
A UNIQUE CRYSTALLINE TECHNOLOGY is changing the way concrete structures around the world are repaired and waterproofed. Integral crystalline waterproofing provides a more permanent, cost-effective alternate to conventional waterproofing methods.
While conventional waterproofing involves applying a coating or membrane to the concrete surface, integral crystalline waterproofing permanently seals concrete by plugging its natural pores and capillaries and preventing the movement of water through the concrete.
How does integral crystalline waterproofing work?
Crystalline waterproofing products are supplied as a dry powder comprised of Portland cement, silica sand and special chemicals. When mixed with water, this powder forms a thick slurry that can be brush-applied to a prepared concrete surface.
When applied to concrete, the chemicals in the waterproofing slurry are absorbed into the concrete by capillary action (the natural wicking movement of liquids in a porous structure) and diffusion (the natural movement of chemical molecules). Once inside the concrete, the chemicals create a reaction that causes long, narrow crystals to form, filling the pores, capillaries and hairline cracks of the concrete mass. By blocking passageways within the concrete, Integral Crystalline Waterproofing crystals permanently prevent the movement of water in all directions.
As long as moisture is present, these crystals continue to grow throughout the concrete, reaching lengths of many inches or even several feet over days, weeks or months. Once the concrete dries, the chemicals sit dormant until the next dose of water causes the chemical reaction to begin again.
The ability to remain dormant and become active again in the presence of water gives treated concrete the ability to “self-seal”. When new cracks form due to settling, seismic activity, etc., water entering through these cracks reacts with the dormant chemicals, causing new crystals to form and grow to block the cracks and stop the water. Its ability to self-seal is one of integral crystalline technology’s most unique and useful features.
What other benefits does integral crystalline waterproofing provide?
Aside from its self-sealing properties, Integral Crystalline Waterproofing offers a number of other advantages over conventional membrane systems.
For best results, membranes must be applied to the positive side of the leaking concrete structure – that is, the side opposite the source of the water. Unfortunately, in cases such as water tanks, reservoirs or sewage treatment facilities, it is impractical or impossible to access the positive side. Since crystalline waterproofing permeates and becomes part of the concrete, it can be applied to either side of the structure.
Another key advantage of crystalline waterproofing is that it is immune to damage. Membrane systems often fail because they are scraped, punctured, or torn. Because crystalline waterproofing acts inside the concrete, the surface coating is not vital. The majority of active crystalline chemicals migrate into the concrete within the first 28 days, meaning the surface-applied treatment can be completely removed from the surface after this time with little effect.
Integral crystalline waterproofing is also permanent. While membranes will deteriorate over time, Integral Crystalline Waterproofing chemicals remain inside the concrete, offering waterproofing and self-sealing abilities for the life of the structure.
Is integral crystalline waterproofing suitable for use in new structures?
When used in the construction of new structures, Integral Crystalline Waterproofing can generate significant time and cost savings. The technology can be applied to new structures using one of two methods:
Dry Shake Method
When placing concrete slabs for a new structure, a layer of the dry powder product is shaken or spread onto the setting concrete and toweled into the surface. Because new concrete has a high moisture content, the crystalline penetration is immediate and the chemical reaction and crystal growth are accelerated. Since the technology becomes part of the concrete, the surface can be finished smooth.
Admixture Method
Following the success of the dry shake method, an integral crystalline waterproofing admixture was developed. This product is applied right into the concrete mixture before it is placed. This application method combines the self-sealing and damage-immune properties of the slurry application and the quick-absorption of the dry improves concrete’s long-term performance.
Most importantly, though, the admixture method eliminates the need of any kind of surface application at all, and the admixture cost is more then offset by the cost saving realized by eliminating the time and the labor required to apply a produce or membrane to the surface.
How to select an integral crystalline waterproofing product?
A number of companies, including Kryton International and in their subsidiary in India – Kryton Buildmat Co. Pvt Ltd., offer integral crystalline waterproofing products for new and existing concrete structures. When selecting Integral Crystalline Waterproofing products, it is important not to confuse them with products that are simply concrete densifiers or pore blockers. Be wary also of products that claim to grow crystals but really only crystallize as they dry – these products will not permeate the concrete, nor will they reactivate in the presence of water to fill cracks. Ask whether the product you are considering contain silicates, stearates, or tale – these offer temporary waterproofing at best. Finally, be sure your manufacturer offers a long-term warranty on all integral crystalline waterproofing products.
Although originally received with skepticism, integral crystalline waterproofing has been repeatedly and successfully tested and used in virtually every country around the world. Over the past decade, Integral Crystalline Waterproofing has become an accepted replacement for conventional membranes in new construction, offering time and cost savings and flexibility that are unmatched by traditional waterproofing methods.
