Modern concrete is lightweight and porous allowing for moisture and salt penetration
-It is usually not sealed externally afterwards, especially on top
-Rebar is often undersized, not welded, is round and does not grip, and doesn't have an anti-oxidant composition such as brass or chromium
-Designers love to create flamboyant looks such as large unsupported balconies and complete walls of uninterrupted glass. (cring)

I wonder what building practices can be upgraded to prevent spalling, such as rubberizers or plasticizers or natural epoxies in the mix which would prevent air penetration.

https://theabeton.com/blogs/news/colosseum
Curiosity got me researching more on Roman concrete and it was said they got stronger over time instead of getting brittle and weak despite all the rains and harsh sun, and that’s because they had cautiously mixed aggregates like volcanic ash, heavy limestone and seawater in the concrete mix that created extremely durable minerals.

My very limited understanding is that high rise buildings are supposed to have multiple fail safes, and not collapse like that even if one of the supporting features fails.

In the Oklahoma City bombing a massive explosion ripped the entire front side and much of the structure off the building. No building is designed to withstand a terrorist with a huge bomb parked just feet from the front of the building.

Imagine that high rise in San Fransisco that is leaning several inches. That has to be a scary place to live, especially now.

Don't want to take away from this thread too much but not too long ago they tore down a newish apartment building a block away from my office here in Seattle.

https://www.seattletimes.com/seattle-news/9-year-old-belltown-high-rise-too-flawed-to-fix/

That is how it is supposed to be done. When the inspections are timely, and they find flaws too expensive to fix, move everyone out, and rip it down.

Hopefully whoever is responsible for the issues, be it the architect, builder or the contractors, someone made an very expensive mistake. Rather than risk a total collapse or even a partial collapse, tear it down and start over. I bet they do it right next time.

The Empire State Building a building virtually everyone knows and it is 90 years old. It even had a B-25 crash into it in 1945. That is a grand old building. Evidently built when quality was most important not speed or profit for the builder.

Comparing the ESB built in '30(?) to a condo on the beach built in the "80's is like comparing a Sherman tank to Geo Metro. I believe the ESB was built in record time and who knows what kind of profit was made or not.

In addition to lives lost, 130 units, 600k+ each, plus common space, that was an 80+ million dollar building.

After 40 years, I would think management/maintenance played a bigger part than architect/builder.

site is the big factor

sand bars are not good places to build hi-rises

do wonder if this will lower the prices of ocean front buildings local or else where

The lawsuits are flowing already.

https://www.nbcnews.com/news/us-news/resident-files-class-action-lawsuit-after-florida-condo-collapse-n1272355?cid=sm_npd_ms_fb_ma&fbclid=IwAR2DwAWnXOvv WhDiKKb8oIgbU0DRPqUICi983bNwF_NK0Xikr_w92yYvx2M

Living around here has put me off ever living in an apartment again.

All the complexes are stick built.

Massive communities.

Every week there is a complex catching fire.

I'd never sleep.

Empire State Building was i beam and rivets real steel framed
and built on granite solid rock

local condo's are concrete and rebar
built on a sand bar

I think the point was that it was built right to begin with.

gruesome.
i'm going with the roof top "stacking" being the final straw.
perhaps they should have known better. i dunno.

"right" is a relative term. To be cost effective for the condo developer and the residents buying them the buildings are built to code, period. You want to build a to 2x, 3x or 4x the code you get pay for it but good luck selling the units or making a profit.

Why don't they start using a crane to lift clear debris? That seems like the best chance to open up areas to anyone that might still be alive.

^^^ A crane would prob kill anyone still alive...unless it had magnets to lift cement.

URY- AFAIK the Hoover Dam was about the only super project built under-budget and under-estimated time.

Not laying blame here.
It's just another lesson on what went wrong and how to avoid it again.

They will start de-layering debris from the outside inward, starting at the highest point accessible from the perimeter of the collapse footprint. We usually use cranes with slings and grapplers. De-layering starts after the initial void searches are done using K9s cameras and acoustics.

From what I'm hearing, they have already started it.


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Ground radar? That might be useful.

Ground radar would'nt work well in this situation. It would be extremely hard to manipulate it over that type of debris pile. Two, the images are not sharp enough to discern a human form.


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I saw images that they are working up from the bottom through the underground parking garage too. Scary dangerous work.