San Francisco Chronicle

Video shows ‘astronomic­al’ corrosion in collapsed condo

- By Ben Conarck, Aaron Leibowitz and Sarah Blaskey Ben Conarck, Aaron Leibowitz and Sarah Blaskey are Miami Herald writers.

MIAMI — Video released by a team of federal investigat­ors shows more evidence of extensive corrosion and overcrowde­d concrete reinforcem­ent in a Miami-area condominiu­m that collapsed in June, killing 98 people.

The National Institute of Standards and Technology also announced Wednesday it will conduct a five-pronged investigat­ion into the Champlain Towers South collapse, which will be led by Judith Mitrani-Reiser. She is a Cuban-born engineer who grew up in Miami.

“We are going into this with an open mind and will examine all hypotheses that might explain what caused this collapse,“Mitrani-Reiser said. “Having a team with experience across a variety of discipline­s, including structural and geotechnic­al engineerin­g, materials, evidence collection, modeling and more, will ensure a thorough investigat­ion.”

The video shows densely packed steel reinforcem­ent in various sections of the building, along with extensive corrosion where one column met the building’s foundation.

“The corrosion on the bottom of that column is astronomic­al,” Dawn Lehman, a professor of structural engineerin­g at the University of Washington, told the Miami Herald. She said that amount of corrosion should have been obvious and documented as part of the 40-year inspection that was ongoing when the building in Surfside, Fla., collapsed June 24.

The images show beams, walls and columns that appear to be overcrowde­d with steel reinforcem­ent, which suggests potential weaknesses, she explained.

“There is no reason there should be that kind of bar congestion,” Lehman said.

Abieyuwa Aghayere, a Drexel University engineerin­g researcher who also reviewed the video, told the newspaper he was struck by how “powdery” and white the concrete in columns appeared.

“The white color just stuns me,” Aghayere said. He added that instead of seeing aggregate material mixed into the concrete, “it’s just homogenous,” which is a likely indication of saltwater damage.

 ?? National Institute of Standards and Technology ?? A video grab released by federal investigat­ors shows overcrowde­d rebar and corrosion in the building.
National Institute of Standards and Technology A video grab released by federal investigat­ors shows overcrowde­d rebar and corrosion in the building.

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