High Strength Concrete Compression Test

[BroBijak]

im doing some investigation at my site. any method to somewhat check the strength of the 'used test cubes'.

would Ndt-hammer on those post-test cubes do the job?

[JSSTyger]

@picmario

I was talking about slab -on-slab impact. This video is trying to say "hey look concrete can be pulverized under high enough loading". I was saying no it does not because breaking a cylinder like this is a slow process and cracks and deformations have time to thoroughly propogate through the concrete before it explodes.

I'm saying the pulverized cylinder here is not proof the WTC slabs would also pulverize.

[rutgerscivilengr]

Slump was zero, high stone & cement content, used mid and high range water reducers. W/C was 0.22

[nighthawk5556]

I want one of those testing crushers. . . . I'd put my old monitor in it, so I could bag up the pieces and put them in a trash bag rather than take it to the landfill and pay for it to be buried

[kirbyman1kanden7pf]

wow...

[JSSTyger]

"Hey Im planning on making a video debunking nutty 911 "truthers" and..."

I work in this field. I've broken concrete cylinders just like this one. Something for you to note...

The incremental load increase here is very slow. Internal cracking and separation has already begun well before the "explosive" failure. The result here is a much more thorough pulverization than you would expect under the same impact loading (15 ksi). WTC concrete failed almost universally from impact loading.

[Hexxle]

Stop trying to sound smarter than you are - you probably copied that straight off of Wikipedia, or something similar to that.

[JSSTyger]

I think you missed the part where I said "I work in this field. I've broken concrete cylinders before."

I can tell you quite a bit more. Try not to be so moronic when you reply.

[thecandidate0607]

You have broken cores like this? What was the structure it came from or the structure its intended to be poured in?

[JSSTyger]

"You have broken cores like this?"

I've broken cylinders just like this up to 5,000 psi (design) strength with a 6" diameter and 1' height. That is not considered "high strength" concrete but the principles remain the same. Deformations/cracks occur internally before the big "explosion". A high strength concrete will, however, break much more thoroughly...but again, we are talking slow steady loading...not impact loading (ie jackhammer on pavement...the pavement remains in chunks).

[thecandidate0607]

Alright I was just wondering, I just finished my material strengths class. I think the cylinders seen in the video are used in things like bridges and dams. I saw basically the same cylinder in an episode of extreme engineering on the history channel where they needed to withstand the impact of icebergs on the bridge piers.

[JSSTyger]

"I just finished my material strengths class."

Sounds like you are gunning for a degree in either Civil or Mechanical Engineering. If you are going Civil, you will probably take a course in reinforced concrete design and will be making and breaking cylinders like this in lab.

[thecandidate0607]

No, Construction management.

[Vasileios1978]

guys do any1 know if theres anything decent in you tube about metal structrures ( I-sections) and forces acting on these sections (tension compression moments etc) thank you

[sonny69ae]

maybe ur speed is too much.. or you are using too much pace rate

[zaloturm]

im trying to find a test of compression failure for steel or some kind ok rigid material. anyone knows where to find it? or at least a picture of the failure...

[rutgerscivilengr]

The strength is consistant within the batch, the problem is reproducing the results with different mixes. This type makes for great videos but is rarely used in construction.

[3of11]

was the batch consistent? Seems like most trouble with making such ultra hi strength concrete is making it consistently.