Lateral ejection of debris trash

That was what first came to mind when I started reading this thread. I remember doing compression tests on high strength concrete in school. After getting to about 40,000 lbs of compressive force (10,000 psi), all of a sudden BOOM, the concrete would shatter and fling stuff all over the room. We had a steel cage around the concrete and stuff would still fling through the holes.

For anyone who's interested, concrete actually fails in tension, even when a compressive force is applied. Concrete cylinders fail at about a 60 degree angle, representing the line of maximum shear.
Yeah, I remembered coming across this stuff when I was trying to find out how many joules were need to crush X lbs concrete to 60 microns when dealing with Hoffman's paper.
 
I don't know if anyone has said this yet, but you can prove the lateral ejection of debris quite simply. Take a stiff object that you're willing to break, like a twig for instance. Stand it up with its end on a table and push down the other end. Notice that it bends outward, and watch where it flies when it breaks.

I could just save you the suspense and tell you that it breaks in a lateral direction. And yes, this comparison can also be made with steel beams. If it can't, you'd better tell that to my deformable body mechanics professor who often made demonstrations with pieces of chalk and compared that to the deformation of steel beams!

I have often wondered if this was a valid comparison to make . Common sense told me yes but since it is outside my area of knowledge I have never used it .
 
I have often wondered if this was a valid comparison to make . Common sense told me yes but since it is outside my area of knowledge I have never used it .
Extremely valid comparison.
The really neat thing about science is that equations are used to represent reality, and they don't change! The variables will change, due to differences in material or configuration--which is why the book gives us equations like Y=(P*L^3)/(48*E*I)

ETA: If you are going to check this out, use a straight twig (or length of Balsa Wood, Eye protection, and either heavy leather gloves, or some sort of protection for the palm of your hand that is pushing.
Failure is spectacularly catastrophic--and sharp chunks of stuff through the hand are no cause for delight.
 
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