MIAMI (AP) – Video released by a team of federal investigators shows more evidence of the extent of corrosion and reinforcement of massed concrete in a Miami area condominium that collapsed in June and killed 98 people.
The National Institute of Standards and Technology also announced Wednesday that it will conduct a five-axis investigation into the Champlain Towers South collapse, which will be led by Judith Mitrani-Reiser. She is an engineer of Cuban origin who grew up in Miami.
“Let’s go at this with an open mind and examine all the hypotheses that can explain what caused this collapse,” Mitrani-Reiser said. “Having a team with experience in a variety of disciplines, including structural and geotechnical engineering, materials, evidence gathering, modeling and more, will ensure thorough research.”
The video shows densely packed steel reinforcements in various sections of the building, along with extensive corrosion where a column met the building’s foundations.
“The corrosion at the bottom of this column is astronomical,” said Dawn Lehman, a professor of structural engineering at the University of Washington., he told the Miami Herald. He said the amount of corrosion should have been obvious and documented as part of the 40-year inspection that was underway when the Surfside, Florida building collapsed on June 24..
“If there’s that amount of corrosion, it should have been fixed,” he said.
The images show beams, walls and columns that appear to be overcrowded with steel reinforcements, suggesting possible weaknesses, he explained.
“There’s no reason for there to be this kind of bar congestion,” Lehman said.
The risk posed by the “congested” vertical barbell in the columns would have been even worse in places where the barbell overlapped, known as “vault joint” regions, the Abieyuwa Aghayere newspaper reported. , an engineering researcher at Drexel University who also reviewed the video. .
Although it is already congested from bar to bar, in the joint regions, it would have been “even more congested,” Aghayere told the Herald.
He said he was surprised by the way the concrete in the columns appeared “powdered” and white in the recently released video. Stone-like aggregates used to reinforce concrete during construction usually remain visible, but were not found in the images of the collapse site.
“The color white just surprises me,” Aghayere told the newspaper. He added that instead of seeing aggregate material mixed with concrete, “it’s just homogeneous,” which is probably an indication of salt water damage.
He said it is impossible to tell from the images whether the concrete used in the original construction was weaker than the required designs or whether the apparent weakness was due to damage over time.
“It doesn’t look like normal concrete. What’s going on? ”Aghayere said.