 A total of 3 @,@ 250 @,@ 000 cubic yards ( 2 @,@ 480 @,@ 000 m3 ) of concrete was used in the dam before concrete pouring ceased on May 29 , 1935 . In addition , 1 @,@ 110 @,@ 000 cu yd ( 850 @,@ 000 m3 ) were used in the power plant and other works . More than <unk> miles ( <unk> km ) of cooling pipes were placed within the concrete . Overall , there is enough concrete in the dam to pave a two @-@ lane highway from San Francisco to New York . Concrete cores were removed from the dam for testing in 1995 ; they showed that " Hoover Dam 's concrete has continued to slowly gain strength " and the dam is composed of a " durable concrete having a <unk> strength exceeding the range typically found in normal mass concrete " . Hoover Dam concrete is not subject to alkali – <unk> reaction ( <unk> ) as the Hoover Dam builders happened to use <unk> aggregate , unlike that at downstream Parker Dam , where <unk> has caused measurable deterioration . 
