Air Liquide Cools Temperatures at Hoover Dam.

HOUSTON -- The Hoover Dam is one of the largest hydroelectric dams in the world and one of the most magnificent sites in the western United States. So much so, traffic on U.S. Highway 93, which runs across the dam in the Colorado River and is the main road connecting Las Vegas to Phoenix, often comes to a standstill as travelers slow down to take in the view. With the help of Air Liquide's CryoCrete technology, a bypass bridge is being constructed that will open the route to smooth travel once again.

Such a massive undertaking requires many cubic yards of concrete with special placing and curing requirements. Using liquid nitrogen to cool concrete mixtures to exacting specifications, CryoCrete injection technology was used in the Hoover Dam bypass bridge project to reduce the temperature of the concrete being used in the bridge's footings prior to it being pumped down to molds resting nearly 300 ft into the canyon. CryoCrete technology resulted in cooling the concrete some 20 to 30 degrees F and was integral in delivering a quality pour and precise curing necessary to ensure the utmost structural integrity of the bridge.

Said Etienne Lepoutre, president of Air Liquide Industrial U.S. LP, "This has been a spectacular opportunity for Air Liquide to contribute to a project at this historic site. It is a world-scale example of the capabilities of the CryoCrete process, a technology with a wide range of industrial applications."

CryoCrete cooling and injection technology is an offering of Air Liquide Industrial U.S. LP. It is the ideal solution for handling the most demanding concrete cooling requirements and placing temperature specifications during extreme hot weather conditions. CryoCrete efficiently and cost-effectively reduces the temperature of a concrete load prior to pouring by delivering liquid nitrogen into the load of each mix truck via a specialized injection method. The result is a drop in the temperature of the concrete of varying degrees, depending on application needs and ambient temperature. CryoCrete has been used in a variety of mass pour applications including the San Francisco-Oakland Bay Bridge.

The Hoover Dam Bypass Bridge is a project of the U.S. government as well as the states of Arizona and Nevada. The bridge is being constructed by Obayashi/PSM JV. Air Liquide is a subcontractor on the project to provide liquid nitrogen and CryoCrete technology. The Hoover Dam, itself, was constructed during the 1930's to harness the power of the Colorado River as a major source of hydroelectric energy and flood control for the region.

Air Liquide Industrial U.S. LP is the subsidiary of American Air Liquide Holdings, Inc. responsible for providing bulk gases and related services to a diverse base of industrial customers in the U.S. Air Liquide Holdings, Inc. is the subsidiary of Air Liquide Group responsible for its North American operations.

Present in more than 70 countries, Air Liquide is the world leader in industrial and medical gases and related services. The Group offers innovative solutions based on constantly enhanced technologies. These solutions, which are consistent with Air Liquide's commitment to sustainable development, help to protect life and enable our customers to manufacture many indispensable everyday products. Founded in 1902, Air Liquide has nearly 36,000 employees. The Group has successfully developed a long-term relationship with its shareholders built on trust and transparency and guided by the principles of corporate governance. Since the publication of its first consolidated financial statements in 1971, Air Liquide has posted strong and steady earnings growth. Sales in 2005 totalled 10,435 million euros, with sales outside France accounting for almost 80%. Air Liquide is listed on the Paris stock exchange and is a component of the CAC 40 and Eurostoxx 50 indices (ISIN code FR 0000120073).