Hoover Dam is a concrete arch-gravity dam in the Black Canyon of the Colorado River, on the border between the U.S. states of Nevada and Arizona. Constructed between 1931 and 1936.It took a team of more than 10,000 people to construct the dam. Miles of streets were paved and buildings were constructed to accommodate these workers and their families.
The dam utilises approximately 3.25 million cubic metres of concrete. That’s enough concrete to build a two-lane highway from San Francisco to New York City! The dam houses 17 turbines, each capable of generating vast amounts of electricity. Let’s explore the amazing engineering behind the construction of Hoover dam in this video from Lesics.
The first concrete was poured into the dam on June 6, 1933, 18 months ahead of schedule. Since concrete heats and contracts as it cures, the potential for uneven cooling and contraction of the concrete posed a serious problem. Bureau of Reclamation engineers calculated that if the dam were to be built in a single continuous pour, the concrete would take 125 years to cool, and the resulting stresses would cause the dam to crack and crumble.
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Instead, the ground where the dam would rise was marked with rectangles, and concrete blocks in columns were poured, some as large as 50 ft square (15 m) and 5 feet (1.5 m) high. Each five-foot form contained a set of 1-inch (25 mm) steel pipes; cool river water would be poured through the pipes, followed by ice-cold water from a refrigeration plant. When an individual block had cured and had stopped contracting, the pipes were filled with grout. Grout was also used to fill the hairline spaces between columns, which were grooved to increase the strength of the joints.
