Water Holding Structures

For the concrete structures of the attenuation tank, 2,500 cubic meters of concrete was treated with Xypex Bio-San, including the walls and roof slab. In addition to the crystalline waterproofing contained in Xypex admix C-500, Xypex Admix Bio-San also contains bio-active mineral solids that become permanently fixed within the concrete matrix, impairing bio-film formation, thus inhibiting the growth of acid-causing sewer bacteria such as Thiobacillus. The antimicrobial initiates a two-stage kill mechanism that stops the Thiobacillus bacteria from developing, thereby preventing the formation of sulfuric acid.

Qingdao Olympic Sailing Center located on Macau Road, Shinan District, was the sailing-competition venue for the Beijing 2008 Olympic Games. Initially, Xypex Concentrate was used to waterproof just the fire pool in the media center but its successful application resulted in Xypex being subsequently used to waterproof 20 pools, 2 elevator shafts, and 2 platforms. Xypex Concentrate was also used to waterproof the Four Seasons Hall in Qingdao Olympic Village.

The cistern construction consisted of installation of a secant pile wall forming the exterior of the cistern followed by excavation of the space within the piles. A Xypex Admix C-500 NF treated 32” thick slab, thickened to 38” at the outer 8’, was poured to create a waterproof floor of the cistern. An inner liner with a minimum 5” thickness was shotcrete placed against the inner face of the secant pile walls creating a flat surface. A 32” structural wall of Xypex Admix treated concrete was poured against the shotcrete liner to complete the wall assembly creating fully waterproofed walls for the cistern. Finally, a Xypex concrete treated lid with a thickness of 30” thinning to 24” at the outer edges was placed to finish the cistern.

Precision Concrete’s Patel notes that “particularly in the case of the Hemphill channel structure, we upped the Xypex dosage from 2 percent to 3 percent to enhance the crystallization process. That really saved us labor time chasing leaks and saved on injection costs as well. We saw continual healing progress until all the cracks dried up on their own. Now that we have some experience with Xypex we are already recommending it on other projects, including a world-renowned golf course in Georgia.”

The Xypex Admix C-500 admixture used in the Adventure Cove pools crystallizes in the pores and micro-cracks, becoming a permanent and integral part of the concrete structure that will continue to waterproof and protect for the life of the pools. Admix C-500 not only permanently seals the concrete and can heal hairline cracks up to 0.4 mm, it also provides chemical resistance properties that mitigate the attack of chlorides, sulfates and the effects of carbonation and alkali-aggregate reaction.