SAN FRANCISCO (KCBS) – An internationally-known expert who serves as a Caltrans adviser says the agency needs to examine hundreds of at-risk rods on the new eastern span of the Bay Bridge and replace any that are hard enough to be vulnerable to cracking.

John Fisher, professor emeritus of civil engineering at Lehigh University in Pennsylvania, joined a Caltrans peer review panel for the project in 2009. That was several years after the agency made an exception to its ban on galvanized, high strength metal for bridge construction and ordered such rods for the eastern span.

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Fisher told the San Francisco Chronicle that the state’s decision to use those rods was not well thought through because such metal can crack when exposed to the elements. Fisher urged Caltrans to test all bridge rods that are under high stress and replace any that register toward the upper levels of hardness.

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Caltrans received received hundreds of such rods for the eastern span; 32 of them are known to have broken. The agency is planning tests to determine the long term risk of the more than 2,000 additional rods on the span.

Caltrans officials say Fisher’s opinions are valuable and independent and they plan to make sure any defective rods are replaced.

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