Your opinion matters...

Concrete guys will know straight away...

I guess load.

Too much load; compression failure.

^^^This^^^
And possibly a poor concrete design mix. Odd how it blew apart at the steel layer, almost like it wasn't poured simultaneously.
Can't see how or why anyone would do that, though.

I wonder if the steel we see is all that was incorporated in that column? Any more in the interior?

^

bad pour subsequent compression failiure

Gravity

I’m not a concrete guy. But I’m in the industry. I’m going out on a limb here. Vertical compression failure due to improper installation of rebar, or a poor design, engineered, looks like there’s no rebar internally just an outer perimeter. Also, I think it’s a bad mix not enough aggregate?but most likely concrete sitting in the truck, too long, not mixed properly and those lines.

I’d like to add possibility of it not being vibrated enough or over vibrated and aggregate settled to the bottom of the column. I hope you have a definitive answer cash :-)

I'm with BamBam.^

Someone did not reject the 3 hour mixed load that had lots of water added to it to make about a 10" slump--- 45 degree crack--- unedumacated guess

For column that size, it sure looks like they skimp on rebar. Not even installed properly. The verticals look like the number three bar the horizontals I think are way undersized. Not enough steel in that column. Also not installed properly. Just my two. Cents.

My guess is there was a cold joint about 18” above the “4”. As Mark Shubert said, 2 separate pours. Probably the first truck filled the form half way, and the second truck was delayed. By the time it got there, the first pour had begun to set up. This leaves a very weak “cold joint”

Don't know crap.


I don't like how close to the surface the rebar is.

Yeah, I’m going with that also. I work in New York City, the mixers have counters on them, and they counter rotations of the drum depending on the mix. They have to meet a certain amount of rotations. Also, they have timed on how long they’re on the job for and I have seen them rejected.

No one has said Unions yet or Global warming 👍🏻

I'm not a concrete guy by any stretch.
But I see a horizontal line going around the top of the blow out,where the pour was possibly continued the following day. Also don't see any more rebar in the chunks that are contained by the rebar. Possibly not enough rebar for that column.

Wetback labor? Cheapskate contractor who was paying off the inspector so he could minimize the amount of rebar he installed? Maybe both?

Poor concrete

Cold joint and not enough rebar.

rebar is way to small for starters.

Buckling, compressive failure / overload.

Paid off building inspector.

Not enough or undersized rebar would not be a cause of compressive failure, no?

I figured it out, I'm changing my answer to "7."

I believe that that is a cap, in the design of the column, not sure, but I believe it is. Someone mentioned the cold, poor and you could see a vertical separation on an angle, which might be a cold pour. Interesting stuff to say the least Also, was it under engineered? Was the weight load that it was designed to hold two great for that column. At the end of the day somebody screwed up and somebody’s going to pay for that :-)

The floor above is where they filmed that Jardiance commercial with the Blue Whale lady.

Miscalculation in the design department. Steel reinforcement not adequate for load.

Rebar x-ties left out. Just a wag.

Rocky could have something there.

When I was a union carpenter we formed quite a few forms for concrete. The placement of the rebar is too far to the outside. I never saw rebar that close to the outside. Like some othere noticed is there is a crack half way up on a 45 degree angle. If they ran out of concrete and left the first load on an angle like that , it is surely the problem. I have been on jobs that ran short . However, we always made sure the top of the concrete was level when we were waiting on more concrete. If that is the case they should have at least cut 12" rebar and stuck in in the top when waiting for the next load I would have stuck at least a dozen rebars vertically in the top and maybe some horizontal rebar and even tied the " hors" to the vertical rebar, and use 1" rebar at least. The next load comes and the concrete sits flat on the first load , the rebar keeps it from going anywhere. Also, there is a down spout there that could have been leaking for decades. If it gets good and wet , freezes , , thaws , gets wet , 50 times a winter that could surely start to pop the concrete. However, it doesnt look like it is stained from water though , but could be a problem We see how concrete driveways will have a 1" crack . At least up north where frost can raise a whole foundation up 1" and crack the whole basement wall.

I saw it as a patch up ? ( thickness of concrete on the right facial plane, outside rebar) the surrounding floor has been torn up, there's what appears to be a cistern against the wall on the right.
There is a shearing scar that goes from 10-4 inside the bar but rather than a big crack it tried to liquify inside?
Could have been struck by the machine that removed the floor on the side we cant see.
No cracks on the surround so we can rule out earthquake and its really too close to the exterior walls to conclude it was load alone. I dont see seams to indicate it was a prestressed panel exterior.

It broke.

Gravity. The answer is gravity.

Poured it in below freezing temps

First impression improper concrete/curing.

Osky

Maybe LBP was doing a photo shoot up there?

Could be a combination of things already mentioned, cold joint, improper bar placement, but the black tie wire has been suspected in some structural bridge failures so now an epoxy covered wire or stainless wire has been used at the facility near me.

Could be numerous and multiple reasons.

Looks to me like the bar is/was barely inside of the concrete.

Looks like 3/4" bar that may have been 1" inside of the concrete at best.

Surprised to see it isn't epoxy coated bar as well.

I assume we can rule out a seismic event?

If so, I’m sticking with overloaded/under designed, depending on who’s paying the lawyer you’re arguing with.

Possibly poured with too much vertical drop.

Agreed. I was taught rebar doesn’t add compressive strength.

This failure is a compression failure. Either poor concrete ( quality, freezing ) or under designed.

Bad mix. Shouldn't happen as all those pours are supposed to be assay'd and signed off on by an Engineer.

I was wondering about earthquake or shifting.

I was told many years ago from an Engineer that the Concrete in structures is calculated as negative strength.

All of the strength comes from the reinforcing steel and the concrete just keeps the reinforcing steel in place.

This was on a Parking Structure that I was involved with.

Over the years I have thought about what he had told me when I inspect Concrete projects.

Back then I asked the Engineer if all of the concrete is calculated as negative weight then why do we use 3000 , 4000 and 5000 Psi concrete.
Concrete has a compressive strength.

He told me that it does help with compressive forces but concrete is still calculated as a negative when engineering buildings.

As for the blow out of the column.
This could have been created by an earthquake or over loading of the column.

That is what it looks lie to me.

The North ridge earthquake lifted buildings up 8 ft and then dropped them and columns failed just like the one in the picture.

Gravity

In is the undisputed champion

Casting couch auditions. Definitely LBP is to blame

Jimmy Hoffa?

Or any ex wives or girlfriends.

Was this near a walmart or golden corral?

This may be true for tensile strength, but it's not true for compressive strength. Concrete has excellent compressive strength but it lacks tensile strength. That's why pre-cast horizontal beams have all the re-bar at the bottom of the beam. When a horizontal beam flexes under a load, the top of the beam is under compression and the bottom is under tension and that's where the steel is needed.

LBP was on the floor above looking at his phone.

Assuming it was designed with 4,200 PSI concrete...

Assuming it is 3' x 4'...

It has a cross section of 1,780 Sq. Inches

If each bears 4,200 or higher. That is 7.3 million pounds of loading capacity.

FYI... NOTHING weighs 7.3 million pounds.

Not even John Burn's lard ass

BINGO...

Beer

Parking Structures use Post Tension cables as Reinforcement. The Concrete for the decks is only to drive on because you can not drive on just the cables.

I agree Concrete has a great deal of Compressive strength but the Engineer explained to me how they calculate that into the buildings

We used 5000 psi concrete on that project for the Columns and 4000 psi for everything else.

Concrete does not bend well but if you have ever felt the deck bounce up and down as you drive in a parking structure the concrete seems to flex.

That is the cables stretching like rubber bands as the weight shifts over the deck as you drive on it.

Concrete also acts as a protector to the reinforcing steel that is why we have minimum concrete coverage over the rebar.

Years back Newport Harbor had a building collapse into the Bay. It just tipped over.

What was decided by the investigation of what it happened was that the salt water seeped into the columns over the years and rotted out the reinforcing steel and then the columns failed and the building collapsed.

They now use Stainless Steel Reinforcing Steel in areas where they have chemical exposed concretes along with added chemicals in the concrete to slow the effect of deterioration of the structures.

I am still opining about the type of tie wire used, also, now I look at it, I dont see any cross bars (steel) going from one side, hooking onto the other side.

Jews tunneled under the other supports and overloaded it.

For 20 some odd years now they have had a 50 story building approved for construction all reinforcing steel and concrete No steel beams in Lost Angeles but they need to get the Concrete strengths up for the task.

I worked at a Lab that was trying to get concrete designs up to 50,000 psi.
The lab I worked at was able to create mix designs up to 30,000 psi with steel needles and fibermesh and the owner of that lab told me no one working on these designs could break the 30k with steady results.
This Lab closed it doors and the owner retired.
That was a Great loss for the industry.

That owner taught me a lot about concrete.

Vertical reinforcing (and subsequent horizontal ties) appear to lack adequate concrete cover all around the perimeter of the column. Should be minimum of 1 1/2". Vertical reinforcing just "looks" to be smaller than what is really needed. Horizontal ties look like they just go around the perimeter and don't tie the verticals from face to face (in either direction) through the interior of the column. Could also be poor concrete mix design, pouring in too cold or too hot temperature, over or under mixed concrete in the delivery trucks. Or just poor reinforcing or concrete placement and vibration techniques. Can't see what the laps are on the verticals or ties might be. My WAG is a combination of any or all of the above.

Looks to be #8 at 10" to me (I could be wrong). It does have proper stirrups. The rebar is appropriate (most jobs overkill the rebar in a hugely wasteful manner... this rebar is fine).

The real tell-tail is how clean the rebar is after failure... i.e. the concrete just popped off leaving clean rebar.

The problem is that the water:cement ratio is totally fubar.

Someone souped up a hot load with WAY WAY too much field water and made diarrhea.

That’s what the bands you see are for. They are actually bent rebar.

Holy crap... 30,000 PSI concrete.

That is insane math. I would like to have met the team that did that.

When any horizontal span like a parking deck is loaded, the bottom half is under tension and the top half is under compression. So providing a surface to drive on is not the only function of the concrete.

It hasn't failed yet, the building is still standing.

Most likely a mix design that was under rated, probly too much water added or retarder, re bar looks right sized but I see no horizontal bars tied in,(could be Im not seeing them in pic) and the vertical bars should be 3" inside the exterior wall side,, A similar cage 1' inside what you see blown out,, bad engineering an Quality control/quality assurance all around

Stacy Abrams & Rossie O'Donnell overhead on platform side by side for a selfie?

I suspect a Swiss hammer test of the existing concrete would test out about 1,000 PSI... probably less.

Interesting.

I think you're scenario would fail sooner rather than later. That failure looks like the column has been there awhile.

As always a full investigation is necessary to determine the cause.

With LBP it would be cattle crush auditions.

Could be a multiple of mistakes. Maybe poor engineering , faulty construction of the cage, concrete poured out of spec, soil compaction, and seismic connections. Be interested in seeing the other columns . In general engineers over design by 30 percent for safety factor.

Could be they didn't send the horse cocks down to consolidate the 'crete for that column.

This is my job. Structural engineering. Simplified, the load exceeded the capacity. It’s likely this is in a high rise building or parking structure where loads are in the millions of pounds. Without further info it’s hard to tell. Could be an error in design, poor materials (concrete/steel), underestimated load, or poor construction. Usually structural failures are a combination of multiple factors, as there are safety factors to lesson the chance one error leads to catastrophe.

Concrete never has negative capacity (whatever that is), to whoever said that. It does have low tensile strength, hence the addition of steel which has great tensile strength. Concrete’s best property is compressive strength. Not even close to steel’s but less expensive and easy to mold to the desired shape.

Column design is more complicated than pure cross section area times per inch compressive strength capacity. Buckling (think yard-stick used as column) where the column bends out of vertical plane, and compression “bulging” or the squashed marshmallow effect both limit design and often control the design.

Bottom line, lots of possible variables here and without further info we are all guessing.

Damn, I knew you were a propeller-head

Or the gays?

Amateurs.


It was the JOOs!

Hebe Union Gays?

Oh, and just for reference, a loaded 4000 ton grain barge weighs more than 7 million lbs. Maybe they dropped one on top of the column?

Here's my guess:

The ties (not tie wire) are on the outside of the longitudinal bars - that is good. The squares ties were probably fabbed as two "U" shaped pieces - this makes it at easier to tie up the rebar cage. The legs of these ties are overlapped, but must have the proper overlap length - e.g development length. If they don't have this, then the columns would burst into the "chinese lantern" that you see.

A good earthquake can do this kind of damage too.

When you gonna post the answer Cash?

That would be a Schmidt Hammer. Coring and testing is more accurate.

I'm thinking they poured a bad load of concrete. Either too wet, too old, contaminated with excess fly ash or flat out sent the wrong mix design.
If I was the concrete supplier I'd be schitting bricks. That is a very expensive repair.

Yep! Building chit under a structure sucks and is labor intensive.

How did you come by this knowledge perfesser? Are you a grain expert, or were you doing research on party boats for LBP?

TOKYO, Japan - Pieces of concrete have fallen off a pillar of an elevated tracks of the Joetsu Shinkansen Line on Oct. 25 following a series of earthquakes. Photo was provided by East Japan Railway Co. (Kyodo)

Schmidt... Swiss...

Same same.

Ever use one?

Five random samplings would tell a whole lot very quickly. Cores would of course be essential and the definitive "evidence" for the obvious lawsuit.


Of course Slenderness Ratio is a component of all column design. This column seems to have perfectly reasonable ratios IMHO.

The nature of the concrete "chunking" during the failure and the fact that the rebar is 100% clean at every location leads me to believe the water to cement ration was fugged... most probably a load was cooking off in the truck and they souped it and dumped it...

Lack of any visibly fractured course aggregate kinda reinforces all above to me.

Someone said too much fly ash... that is also a very possible culprit.

I 200% the pic...

Many times. I was in the concrete business for 40 plus years.

They are called stirrups and typically they will come as a full rectangle. The will overlap at one end.

24-36 bar diameters is a normal "overlap" or "splice"...

If #8 bar... the "overlap" or "splice" would be 24" - 36"

Earthquake damage. Now we know what went wrong.

Yes

Interesting...

I found the pic on the Web with no further information. PE group I follow some.

Seismic seems odd in that there is no visible damage to any of the other concrete work in the background.

Regardless... a fun little study.

https://www.[bleep].com/tokyo-japan-p...illar-of-an-elevated-image151019849.html

http://rftp.com/concrete-failure.html

Something heavy atop Probly added to the bulge effect

easy , .. it broke .. 😁

Or in other terms "it done come from together"

The wall in the background may not be a load bearing wall.

I knew it!

What kind of boat did he end up getting?

I concur, but seismic don't care.

Do I win something?

I just retired from the Alaska DOT as a Highway Engineer. Worked next to the bridge guys. When they went from ASD to LRFD they needed some full scale testing of columns to verify some stuff. I watched some of these tests and that's the kind of stuff you'd see. Of course, they don't test them to that level of failure.

Sure thing... I'll take you fishing next time you come to Virginia.

The company I was working for was called CHJ there were also several other company's working on it as well
Smith Emery and Twining
I had worked for both of them before I was told by George Batty 3rd (probably miss spelled his name) about what was going on in the Labs.

I was collecting the unshattered test cylinders and cutting the ends off of them to make a small retaining wall when I came across the Steel Needles in some of the cylinders.
I went into the lab and asked my supervisor what the samples were from.
He told me to go talk to George and I did.
George owned aporx. 5% of the company at that time.

He was a GREAT Teacher to us Concrete Inspectors.
I owe that guy a lot for what he taught all of us.

He sat me down and gave me some of his valuable time to explain what the Labs in the area were trying to accomplish.

He explained how several Labs were able to get consistent 30K psi in their mix designs but they could not break any higher on a consistent basis.

Those needles in the concrete were something like 120K tensile strength and the test cylinders were loaded with them.

My Supervisor told me that he was wondering when I was gunna ask about those Cylinders because I always asked a lot of questions to learn about stuff.
I got into Inspection as a Welder Fitter Shop Fab guy and Concrete Inspection came later.

I love what I do because there is always something that comes up that I have never seen and I get the personal guided tours into company's that do not allow anyone in.

I am getting driven out of the industry by book smart desk Inspectors that know very little about what they are inspecting.

Most of what I know for my job did not come from a book it came from personal experience of doing and seeing not reading.

Sad to watch an industry collapse around you as more and more stupid people get the jobs as a stepping stone carrier over the ones that actually know the job , Love the job and live the job.

No idea as to initial cause, I am pleased I don't have to pay for it.

This! and weight....

Um, weight is the result of gravity. In simple terms: Weight = mass x gravity

https://engineeringdiscoveries.com/types-of-column-failure/

Good read also...

FLW and the Johnson Wax Project...

Proof Testing his "Lily pads"

https://www.cnet.com/pictures/why-frank-lloyd-wright-piled-60-tons-on-a-lily-pad-pictures/

I do lots of Proof Testing in my world.

What caused the failure?

A: It cracked and fell apart.

Stacey Abrams?

A few things. One is load and a lot of it. 2 from that shot the rebar looks too close to the forms. Typically 2" clearance is needed for a minimum. 3) it doesn't look like it was properly vibrated and dropped into the column from too high of a distance instead of using a tremme shoot or a pump hose to shorten the fall

I wouldn't say "paid off" but there is plenty of BS with inspectors. Most of them don't want to rock the boat and/or are so busy they spend about 10 minutes on a site where they should be for hours.

Agreed.

A cold pour should really have steel crossing the pour surface towards the center as well.

There's nothing wrong with that rebar size. It's pretty big actually.

The muffin top effect?

Before anything else is considered, this picture screams of lack of bond.

Axis of orientation bears on this. We were doing a concrete building in California for the horizontal structural beams the rebar was tensioned before the pour. After the concrete had set the rebar was cut off leaving the concrete under compression. Of course this doesn't apply to the OPs photo.

My initial thoughts, a seismic event. If that is the case the damage ain't that bad

Driving through Montreal a few years ago we noticed every high structure was crumbling. There is mineral substance in some gravels that becomes gelatinous when used in concrete. It is well known since WWII but still is overlooked. A huge stretch of our interstate had to be ripped up soon after poured. Some idiot didn't check.

.
Looks like a bad mix in that truck.
Maybe consolidation was not up to snuff as well.
I don't know what their inspection/sampling methods are, but they will be looking at those field and lab reports.
We test every 50 yards on a big pour so a truck with a bad mix or the wrong mix design (if no one checked) could slip through.

Forms were too tight.

Reminds me of the current state of the Union.

First I’ve heard of this. What is the substance?

Travis Kelce got pissed and bumped into it.

Geeze, it was a sudden and total failure. Had nothing to do with rebar placement or concrete mix. Had it have been either of those two you'd have been able to see gradual damage resulting in the rebar rusting... you can see in the photo, that the concrete adhered to the rebar just fine and with no gradual cracking.

Phil

Almost certainly a combination of factors.

If you skip to the blue collar end of things and ignore bad engineering etc. it comes down to the oft mentioned mix, most critical is the amount of water and when it was added.

I see no obvious signs of a cold joint.

Rebar looks good but the covering concrete looks substantially too thin, usually youre held to a "window" of acceptable placement, sometimes it just flat tells you "2" clearance to form". It is almost unheard of for the concrete to be spec'd at < 1-1/2" space from outside surface of outmost steel, to innermost surface of form This steel looks to be #8 vert with #5 stirrups and those stirrups are not covered by much grey stuff from what I can see.

The steel did not fail you could argue it is still doing fine even now.

Im guessing the stirrups were made off site and made a bit wrong, the illegal aliens hung it even though it was too close to the forms. Without seeing the off side steel. It is possible the steel was just not centered in the column.

Many a slip tween the footer layout and the wall layout maybe the footer steel being off made it desirable for simplicity sake to have the pilaster steel off centre.

Any idiot can layout a building it takes skill to lay it out twice precisely the same.


I'm betting bad mud and steel not covered by enough of it.

LOL, you can distinguish "gradual cracking" that was present before the failure from cracks resulting from the sudden failure in that photo?

Do tell.

Yes fool, all that cracking occurred at the same time. If you'd ever worked with concrete, you'd know what a bad mix looks like after just a short time.

Phil

Gheyghost is a concrete expurt?

LOL, bullsh*t. A skilled inspector might be able to distinguish between the two in person.


You're neither a skilled inspector, nor there in person.

Every bridge I worked on had qc'ed mud before it ever hit the ground.

Interesting. I did not know you could tension rebar. I knew cables were pre tensioned.

They do not used the Pretension cables as much as they use the Post Tension these days to my knowledge.

Most Post Tension cables are what they call non bonded.
They are in a greased sleeve that allows the cable to move with in the concrete a live loads change

They also use them where they have unstable ground and want to pull the concrete together to stabilize the concrete
(1) 1/2 inch cable from what I have been told equals a #11 bar that is a 1 1/8 inch bar,
Kinda crazy what technology can do.

I worked in an 6 level underground parking structure in down town Lost Angeles years ago shoring up damaged Columns with Steel Beams (the columns had small fractures non like the pic in the original post created by the North Ridge Quake) as the welders would get set up for the day I would walk around looking at stuff.
The walls to the underground structure had up to an 1 1/2 inch gap between the floors.
Now this was an underground Structure with the dirt pressing against the walls.

Then I noticed spawled out concrete concrete in the floor support beams overhead with rusted , very rusted bonded cables these are cables with out the greased sleeves they are like rebar that is connected directly to the concrete.

I would talk to my boss every day and I told him what I seen when walking around.
He came out to the project and I walked him around the project and pointed out what i found.

He was shocked as none of the Engineers mentioned anything about the Beams just the Columns.

He then asked what I thought should be done to fix the issues.
I told him that I was very happy that I was only the Welding Inspector on the project and that I did not have the License to do Concrete in the jurisdiction and that I did not have my Pre Tention/ Post Tension Certification.

He just looked at me funny.

Well they shut the project down for further investigation of the project.
Do not know if and when they ever started the project back up.


I am just happy that I was never called back on that project. It is a liability trap project for anyone involved.

Earthquakes can do strange things to structures.
The Engineers engineer building to with stand Earthquakes just long enough to get people to safety.

There is no such thing as an Earthquake Proof Structure

It looks to me that the Column in the 1st pic did what it needed to do.

It did fail but the structure did not collapses 100%.

They put a lot more Horizontal ties in these days that the use to do to hold the Columns together better when thing get to moving when they are not supposed to be moving.

I really think that we should consider the possibility that ethanol mix and a FRAM filter were used with the vibrator motor.

And that is happening in every industry , every job is more based on Book knowledge , all of our hands on. knowledge is dieing when we do. pass your knowledge on to your kids and grandkids. so that they can survive in our NEW world , control and complyance is every where and the elite uses it to control everything.

Norm

Is there a subject in which he is not an expert?

Obviously caused by climate change.

Winner "Chicken Dinner" to those above who said this wasn't a "failure."