Home Forums Hunting & Shooting Hunter's Campfire What caused this failure?

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.