One month ago, On June 24, 2021, at approximately 1:30 AM (EDT), The Champlain Towers South, north of Miami Beach collapsed. Fifty-five of the building’s 136 units were destroyed with residents still inside.
The collapse happened in 11 seconds leaving behind a massive heap of debris including concrete, steel, and the residents’ personal belongings. A massive search and rescue effort ensued but two weeks after the collapse, the rescue shifted to recovery. As of posting, 97 casualties were confirmed, while 11 injuries and 126 survivors were verified.
What caused the collapse?
Officials have launched an aggressive push to understand why Champlain Towers South collapsed. Engineers were brought to the site to investigate. It is still ongoing and will likely take many months. Experts are suggesting that failure may have come from the structural integrity of the building itself.
The Miami-Dade County city officials released a report from 2018 that showed an engineer’s assessment of the building. The 2018 inspection performed by the engineering firm Morabito Consultants revealed numerous cracking and spalling of varying degrees in the entirety of the building. These signs of deterioration were most common on the concrete columns in the basement garage underneath the building’s pool deck. Leaching of calcium carbonate deposits from the concrete ceiling in different areas was also observed.
The 2018 report showed a “major error” in the construction of the pool deck. Engr. Frank P. Morabito discovered that the waterproofing is straight and not sloped. Water that collected on the waterproofing remained until it could evaporate. Over the years, the concrete slabs below the pool deck had been severely damaged by water. The firm states that "failure to replace waterproofing in the near future will cause the extent of the concrete deterioration to expand exponentially", and that the repair would be "extremely expensive”.
Since the major cause of the collapse is pointing towards concrete deterioration, concrete petrography can be a complementary assessment tool in the investigation in finding the extent of the cracks, corrosion, and leached carbonation observed in the building.
Sources:
Glanz, J., Baker, M., & Singhvi, A. (2021, July 3). Condo Wreckage Hints at First Signs of Possible Construction Flaw. The New York Times. https://www.nytimes.com/2021/07/03/us/florida-condo-collapse-steel-rebar.html.
Harkins, G. (2021, July 10). What you need to know about the Florida condo collapse as the search for survivors continues and probe begins. The Washington Post. https://www.washingtonpost.com/nation/2021/06/25/florida-condo-collapse-what-you-should-know/.
Morabito, F. (2018, October 8). Champlain Towers South Field Survery Report MC Job#12187. https://www.townofsurfsidefl.gov/docs/default-source/default-document-library/town-clerk-documents/champlain-towers-south-public-records/8777-collins-ave---structural-field-survey-report.pdf?sfvrsn=882a1194_2.
Team, T. V. J. (2021, July 1). Miami building collapse: What could have caused it? BBC News. https://www.bbc.com/news/world-us-canada-57651025.