Gulf Construction – November, 2007
Integral crystalline waterproofing (ICW) provides life-long protection of structures, says LEO CONNELL,” while outlining properties of the system which appealed to the builders of one of the world’s largest garages.
In order to prevent damage caused by water and preserve the integrity of concrete structures and thus avoid costly problems in the years to come, it is essential use a proven waterproofing system for the foundations. Whether the foundation needs to be damp-proof or fully waterproofed against hydrostatic pressure, integral crystalline waterproofing (ICW) provides an innovative solution.
ICW systems are changing the way concrete structures around the world are paired and waterproofed, providing a quick and cost-saving alternative to traditional membranes. One such system was used for waterproofing the Kuwait-based Al Ghanim Industries’ new garage, one of the largest such facilities in the world.
While conventional waterproofing involves applying a coating or membrane to the concrete surface, crystalline waterproofing permanently seals concrete by plugging its natural pores and capillaries and blocking the movement of water. It also reacts with coming water to self-seal the cracks that inevitably develop in concrete, protecting structures against the water and contaminants that can weaken or destroy concrete and corrode steel reinforcement.
Al Ghanim Industries recently built its $45 million garage in Shuwaikh, near Kuwait City. The facility has the capacity to service and park more than 1,000 cars on its maintenance level, making it one of the largest vehicle garages in the world.
The concrete floors or slabs in the service area of the garage will be constantly wet and in need of waterproofing protection due to the heavy use of water during the maintenance work. The builders required a proven concrete waterproofing solution that would prevent water from penetrating the slab – one that would ensure water would not leak through the slab to the floor below.
The builders also sought a waterproofing solution that could function well with the slab, which needed to be drilled to incorporate mechanical mounts to hold heavy machinery. They were concerned that a traditional membrane would suffer damage from the drilling and therefore would no longer be functional.
Potential leakage and costly, time-consuming repairs were a major concern as a traditional membrane could not be guaranteed to be watertight around each drill opening.
This apart, the team wanted to start pouring the concrete quickly since the sophisticated building plans took more time than originally estimated and hence wanted to speed up the construction.
Selecting the right solution
The project team had a wide range of waterproofing systems to choose from, including:
Advantages of ICW
After considering each option, the Al Ghanim project team select an ICW system because it offered a number of key advantages over other alternatives as it:
The Al Ghanim team found the ICW system particularly appealing because of its longevity, as although an external membrane system may be properly applied, it has a finite useful life. It eventually dries, cracks, peels or otherwise deteriorates following exposure to ultraviolet light and hot/ dry conditions. The result is a compromised structure that is vulnerable to water leakage.
How does ICW work?
When applied to existing concrete, crystalline chemicals are absorbed into the concrete by capillary action (the natural wicking movement of liquids through a porous structure) and diffusion (the natural movement of chemical molecules.)
Once inside the concrete, crystalline chemicals begin growing crystals and filling the spaces between concrete particles. As long as moisture remains present, crystals continue to grow throughout the concrete, reaching lengths of many centimeters over time. Once the concrete has cured, the crystalline chemicals sit dormant until another dose of water (such as through a new crack, or rising water table) causes the chemical reaction to begin again.
The ability to reactivate in the presence of water gives crystalline-treated concrete the ability to “self-seal”. When cracks form due to curing shrinkage, settling, seismic activity, etc, water entering through them causes new crystals to form and grow, blocking and filling the cracks. Its ability to self-seal cracks is one of crystalline technology’s unique and most useful features, and can help to dramatically reduce the long-term maintenance and repair costs of a concrete structure.
In hot weather, external membrane systems can become brittle and deteriorate when exposed to prolonged heat, resulting in leaks and increased repair and maintenance costs. Crystalline chemical are unaffected by climate and remain effective for the life of the structure.
Also, the soil in hot or tropical climates may contain high levels of sulphates, chlorides and other chemicals that decrease the integrity of concrete and corrode steel reinforcements. By blocking the penetration of water that can carry these contaminants and safeguarding concrete and reinforcements against corrosion, crystalline systems will long a structure’s useful life.
How is ICW applied?
ICW products are usually supplied as an easy-to-use, dry powder comprising Portland cement, silica sand and special chemicals that can simply be added to the readymix truck at the plant or jobsite to create a power moisture barrier in slabs and walls. There is no need for any sort of surface application at the construction site – crystalline waterproofing can be simply added to the concrete.
Such systems can also be surface-applied to existing walls and slabs and incorporated into construction joints during construction or after the fact.
AI Ghanim selected Kryton International’s Krystol Internal Membrane (KIM) for waterproofing a total of 4,500 cu m on the ground floor and first floor slab (12,000 sq m of area). The Krystol waterstop system was also used to treat the drill openings made for mechanical mounts.
By using the Krystol waterproofing system, the project team saved two months of construction time. fu a result, the Al Ghanim Garage opened two months ahead of schedule that translated into approximately $850,000 to $1. 7 million worth of business. In addition, the savings in construction costs alone by employing the Krystol system over a traditional membrane system was $69,000. The use of Krystol eliminated numerous steps traditionally required with waterproofing the slabs and created the foundation for a watertight structure.
ICW products such as Kryton International’s KIM, which is certified nontoxic, are ideal for use in a wide variety of precast, shotcrete and cast-in-place applications such as bridges, dams, tunnels, swimming pools, water storage and wastewater treatment facilities, reservoirs, pipelines, parking garages, basements and foundations.
When choosing a system, time should be taken to assess each product, bearing in mind the specific requirements and challenges of the project. Before selecting a waterproofing system, one should ask lots of questions, carefully review brochures and literature and speak with manufacturers’ technical service representatives, if additional information is needed. It may even be worthwhile to have a manufacturer’s field representative visit the site.
Investing the time to research, compare and select the best waterproofing system for the structure will save a lot of time and expense in years to come.
* Leo Connell is director of marketing at Kryton International, Vancouver, British Columbia, Canada. Kryton International products are distributed in more than 40 countries worldwide. They have been tested and approved by Kuwait University, Dubai Municipality and Saudi Aramco. Further information about Kryton International or integral crystalline waterproofing, can be obtained from its website (www.kryton.com).