Concrete waterproofing is an important issue in the design and construction of foundations and other subsurface structures. However, when concrete is not properly cured, it can become porous and allow water to seep through openings or cracks.
To stop the leakage, a waterproofing membrane is applied. This typically consists of an alternating layer of bituminous asphalt and bitumen felt, which is heated to create a sheet system. Traditional built-up bituminous membranes release toxic and hazardous volatile organic compounds (VOCs) that can cause respiratory and eye problems in workers as well as the general public.
A proven alternative is crystalline waterproofing technology. Crystalline products are manufactured as dry powders that consist of portland cement, very fine treated silica sand, and selected chemicals.
The chemicals in crystalline waterproofing admixtures react with the by-products of cement hydration to form a nonsoluble crystalline formation that bridges and seals capillary tracts, cracks, and pores in concrete. Scanning electron microscope images have shown that newly formed crystalline structures act as bridges to prevent the diffusion of liquids into concrete and create a permanent, waterproof condition.
When used in the proper combination with properly cured concrete, crystalline technology can be used to waterproof almost any type of concrete structure. This includes, but is not limited to, basement walls, elevator pits, cisterns and other concrete foundations that may be subjected to special design conditions that require extra protection.