VANCOUVER, BC… A new Saint Louis Zoo sea lion exhibit, set to open this summer, features a shotcrete exterior made with a Xypex® Concrete Waterproofing through Crystallization™
The $18-million, 1.5-acre habitat and arena will initially be home to 11 sea lions and later will include harbor seals.
The Saint Louis Zoo was named America’s #1 Zoo by Zagat Survey’s first-ever U.S. Family Travel Guide in association with Parenting magazine. In addition, the Zoo tied for first place as the top attraction overall. The Zoo receives about three million visitors each year.
Since its inception in 1910, the Saint Louis Zoo has been renowned for its beautiful naturalistic exhibits and for its diverse collection of animals from the major continents and biomes of the world.
The new sea lion exhibit’s thematic concrete rock work was constructed by Cemrock, based in Tucson, AZ and Seattle, WA. Cemrock specializes in the construction, fabrication and installation of artificial and themed elements, including artificial rock work, water features, animal and aquarium habitats, large steel & concrete or fiberglass & epoxy trees, sculptural elements, and more.
“We have a thorough, working knowledge of Xypex concrete waterproofing products,” says Scott Chandler, Cemrock Project Superintendent for the zoo project. “For a number of reasons, including the fact that this exhibit will hold 258,000 gallons of salt water, this was a high-risk project that required a zero-tolerance concrete waterproofing solution.”
The Xypex admixture was used in all of the shotcrete for streams and waterfalls, as well as in poured concrete for three walls. About 1,200 yards of shotcrete was applied. An overall total of 4,830 lbs. of Xypex C-500 Admix was used (for both shotcrete and poured slabs).
Xypex Concrete Waterproofing by Crystallization was specified by the project’s architect, St. Louis-based PGAV Destinations (Peckham Guyton Albers & Viets, Inc.), a leader in destination planning and design, including zoos and aquariums; cultural, heritage and tourism sites; and other attractions. The work of PGAV Destinations has involved some of the most recognizable destinations in the United States and elsewhere, including Busch Gardens (Tampa, FL), Universal Studios (Orlando, FL), and Biltmore Estate (Asheville, NC).
“Through research and value engineering on multiple exhibit projects,” says Project Manager Mariusz Bleszynski AIA, LEED® AP of PGAV Destinations, “we discovered that a concrete pool vessel made watertight by a crystalline concrete admixture or surface treatment is a very economical construction method. This is especially true for the sculptured artificial rockwork pools, where a surface applied waterproofing is not aesthetically or economically viable. We have found the Xypex line of products work well for free-formed shotcrete exhibit pools as well as cast in place concrete basins for water treatment processes.”
Other key firms involved in the construction of this project include Alberici Constructors (Project Managers) of St. Louis; Rhodey Construction of St.Louis; Raineri Building Materials of St. Louis; and Ameristar Building Products of St. Charles, MO. Cemrock was the applicator.
Xypex Chemical Corporation’
The technology uses concrete’s inherent water permeability to deliver crystalline chemicals that plug the material’s pores and to bridge micro-cracks that occur as the concrete dries and shrinks. The chemistry can be easily introduced into new concrete as an admixture, a dry-shake product, or a surface-applied coating. All of the concrete in the Saint Louis Zoo sea lion exhibit project was treated with Xypex C-500 Admix. For existing (i.e., cured) concrete, surface-applied coatings are used.
Because concrete is permeable to liquids and gases, porous conditions can create multiple problems within a structure due to moisture penetration. The infiltrating water, and harmful chemicals dissolved within, also can compromise the concrete itself.
The Xypex Crystalline technology uses water in the capillary tracts as a diffusing medium to carry waterproofing chemicals into the concrete. The chemicals migrate through the waterways of the saturated pore network, where they react and grow non-soluble, needle-like crystals that plug the pores. Within a few weeks of crystal growth, liquids can no longer pass through and the transmission of gases is significantly restricted.
Crystallization becomes an integral, permanent part of the concrete matrix. The technology will even self-seal new micro-cracks if and when they occur years after the original application.
The treated concrete cannot be punctured or damaged like a liner or surface coating; it
withstands high hydrostatic pressure from both the positive and negative side; and is not affected by humidity, ultraviolet light or oxygen levels. A crystalline technology such as the
Xypex-developed solution, is a modification of the concrete itself and hence is permanent and will not blister or fail.
Crystalline waterproofing protects the environment from contamination caused by leakage. The Xypex waterproofing technology makes the construction process greener by eliminating the need for membranes manufactured with plastics, asphalt, polymer resins, solvents, aromatics and other materials with high energy manufacturing costs.
The Xypex crystalline waterproofing technology is non-toxic, contains no VOC's (volatile organic compounds), and is NSF-61 approved for potable water by NSF International, a widely-accepted, independent source of public health and safety standards around the world.
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Xypex Chemical Corporation (www.Xypex.com)