Dump Truck @ 50 mph vs. Wall .... ** video with results **

[rahvin]

Originally posted by: DuffmanOhYeah
Poor test of a wall. Im guessing it is a wall intent on stopping a run-away terrorist or the like. That hopper was empty. A smart terrorist would load that thing full. 3x the mass and you would make a whole mess of that barrier.

I doubt it would make a difference. The concrete may yield but the steel wouldn't.

 

[CPA]

Originally posted by: sparkyclarky

Originally posted by: XZeroII
Here is WI we actually had a dump truck blow a tire and fly through the median baricade on the freeway into oncoming traffic. It was a mess.

I seem to remember that, but I also remember that truck that had a wheel come clean off. Just driving down the road and it looses a wheel?!

I saw that happen here in Houston a few years ago. But the wheel came off a minivan and we was able to stop the vehicle before anything horrible happened. So, I guess it's not really the same thing.

 

[MrDudeMan]

Originally posted by: rahvin

Originally posted by: DuffmanOhYeah
Poor test of a wall. Im guessing it is a wall intent on stopping a run-away terrorist or the like. That hopper was empty. A smart terrorist would load that thing full. 3x the mass and you would make a whole mess of that barrier.

I doubt it would make a difference. The concrete may yield but the steel wouldn't.

yield? im not even sure that is the right word, but if you meant to say deflect, you are wrong. concrete has a very low elasticity and will not bend or stretch, especially with an impact load. dead loads can cause it to deflect SLIGHTLY but it has to be a huge slab or be carrying a lot of weight, as in, several thousands of pounds. the steel would bend because its elasticity is like 29 million PSI compared to less than a million for concrete.

 

[rahvin]

Originally posted by: MrDudeMan

Originally posted by: rahvin

Originally posted by: DuffmanOhYeah
Poor test of a wall. Im guessing it is a wall intent on stopping a run-away terrorist or the like. That hopper was empty. A smart terrorist would load that thing full. 3x the mass and you would make a whole mess of that barrier.

I doubt it would make a difference. The concrete may yield but the steel wouldn't.

yield? im not even sure that is the right word, but if you meant to say deflect, you are wrong. concrete has a very low elasticity and will not bend or stretch, especially with an impact load. dead loads can cause it to deflect SLIGHTLY but it has to be a huge slab or be carrying a lot of weight, as in, several thousands of pounds. the steel would bend because its elasticity is like 29 million PSI compared to less than a million for concrete.

I used yield in an improper techincal context to convey meaning to the layman. The concrete has nearly zero tensile strength and would likely fracture extensively under a fully loaded dump truck hitting it (the tensile zone would fail and the compresive zone would facture under the cracks induced by failure in tensile zone). The steel itself depending on how much there is would possibly move into the plastic zone but would not fail as the tension required to totally yield the steel would be far more than could be generated.

 

[CraigRT]

omg lol!
that's insane!!

 

[sygyzy]

Why is the title of this thread "..with results" Is the OP going to chime in and tell us specifically what happened at the end? Yes, you can see the wall won, but by putting "with results" I was hoping to get more information (ie. how much of the wall was damaged, how it was built, how much force the truck felt, etc).

 

[Ymmy]

The wall barely got dented... it looks flexible, in fact. but the entire cab was crunched...

Thanks alot for ruining it for me.

 

[rh71]

Originally posted by: Eli

Originally posted by: rh71
listen to that whine

What does that have to do with this thread?

Nice video tho. Love that whine.

Grabbed from the same server - is all.

 

[Armitage]

Impressive ... I'd be interested to know how much weight was in the truck ... looked like there was some kind of cover over the dump body??

I'd expect the results to be even more spectacular with a load of rock in the back (or the weight equiv. of a load of ANFO). I doubt there would be much left of the truck, if the wall held.

 

[Bassyhead]

nice wall

 

[NeoPTLD]

Originally posted by: rh71

Originally posted by: Eli

Originally posted by: rh71
listen to that whine

What does that have to do with this thread?

Nice video tho. Love that whine.

Grabbed from the same server - is all.

But there's no big crunch

 

[MrDudeMan]

Originally posted by: rahvin

Originally posted by: MrDudeMan

Originally posted by: rahvin

Originally posted by: DuffmanOhYeah
Poor test of a wall. Im guessing it is a wall intent on stopping a run-away terrorist or the like. That hopper was empty. A smart terrorist would load that thing full. 3x the mass and you would make a whole mess of that barrier.

I doubt it would make a difference. The concrete may yield but the steel wouldn't.

yield? im not even sure that is the right word, but if you meant to say deflect, you are wrong. concrete has a very low elasticity and will not bend or stretch, especially with an impact load. dead loads can cause it to deflect SLIGHTLY but it has to be a huge slab or be carrying a lot of weight, as in, several thousands of pounds. the steel would bend because its elasticity is like 29 million PSI compared to less than a million for concrete.

I used yield in an improper techincal context to convey meaning to the layman. The concrete has nearly zero tensile strength and would likely fracture extensively under a fully loaded dump truck hitting it (the tensile zone would fail and the compresive zone would facture under the cracks induced by failure in tensile zone). The steel itself depending on how much there is would possibly move into the plastic zone but would not fail as the tension required to totally yield the steel would be far more than could be generated.

so yield is the wrong word. good. next, concrete has tensile strength, but it is only 10% of its compressive strength. you can increase the tensile strength by incorporating polyproylene fibers into the concrete matrix, which also act as crack arresters. what if this wall were in compression? are you forgetting that concrete in compression has much higher resistance to flexure, even in the lateral direction? or are you reading this from a book? at its maximum ductility, concrete with poly fibers and steel mats would hold back a dumptruck while sustaining maybe a few cracks. i doubt it would fracture so badly that there would be a gaping hole in the wall. of course, that all depends on the size, depth, and type of concrete, but most types (if reinforced correctly) would resist this truck.

 

[PowerMacG5]

The scary thing is something like that happened to one of my fathers drivers. He fell asleep one night coming home from a job in a Straight Job truck (similar to those tow trucks that you see with the flatbed that comes out and down with hydraulics), and a curve was up ahead and he smacked into it. From what I was told the truck flipped, but the guy lived.

 

[rahvin]

Originally posted by: MrDudeMan

so yield is the wrong word. good. next, concrete has tensile strength, but it is only 10% of its compressive strength. you can increase the tensile strength by incorporating polyproylene fibers into the concrete matrix, which also act as crack arresters. what if this wall were in compression? are you forgetting that concrete in compression has much higher resistance to flexure, even in the lateral direction? or are you reading this from a book? at its maximum ductility, concrete with poly fibers and steel mats would hold back a dumptruck while sustaining maybe a few cracks. i doubt it would fracture so badly that there would be a gaping hole in the wall. of course, that all depends on the size, depth, and type of concrete, but most types (if reinforced correctly) would resist this truck.

I realize that you think you know what you are talking about because if I remember correctly you are recently graduated and think you know everything (or even worse are still in college and really think you know everything). For all intensive purposes concrete has no tensile strength and that's a near direct quote from the PCA design book. As you should be well aware those fiberglass fibers you talking about using in the mix drasticly alter the concrete, and mix designs such as that are highly controversial. If I remember correctly the fibers result in an increase in tensile strength and a corresponding drop in compressive strength. They also have a nasty tendency to reduce the fire resistance of the mud (and who the hell knows what they do to air entrainment and whether superplastisizers have to be used to even make it finishable)

Any wall can be designed to sustain an impact with any load and I admit I have not watched the video. Chances are though that unless the wall is similar to those designed to house nuclear reactors the concrete will crack and cracks are failure. The amount of force generated by the impact of an HS-20 load stoped near instantly is immense. A 10 wheeler hit a local bridge near where I work (I don't know it's load status). It did 45mph to 0mph in 1 foot. (the deflection of the I-beam it hit). Concrete can take the impacts but it will crack under the impact (I've seen plenty of Precast I-beams hit) unless it has enough mass to sustain the impact without exposing too much of the section to tensile forces. I've seen cast in place single slope barrier with 6 bars on each face (1meter high, half a meter bottom width and 0.100m top width) and hooks at the top busted all to hell from a 20^ impact by what was likely an HS-20 load.

One other thing you should keep in mind, there are other Civil Engineers on this board and some probably have more experience than you do.

 

[MrDudeMan]

Originally posted by: rahvin

Originally posted by: MrDudeMan

so yield is the wrong word. good. next, concrete has tensile strength, but it is only 10% of its compressive strength. you can increase the tensile strength by incorporating polyproylene fibers into the concrete matrix, which also act as crack arresters. what if this wall were in compression? are you forgetting that concrete in compression has much higher resistance to flexure, even in the lateral direction? or are you reading this from a book? at its maximum ductility, concrete with poly fibers and steel mats would hold back a dumptruck while sustaining maybe a few cracks. i doubt it would fracture so badly that there would be a gaping hole in the wall. of course, that all depends on the size, depth, and type of concrete, but most types (if reinforced correctly) would resist this truck.

I realize that you think you know what you are talking about because if I remember correctly you are recently graduated and think you know everything (or even worse are still in college and really think you know everything). For all intensive purposes concrete has no tensile strength and that's a near direct quote from the PCA design book. As you should be well aware those fiberglass fibers you talking about using in the mix drasticly alter the concrete, and mix designs such as that are highly controversial. If I remember correctly the fibers result in an increase in tensile strength and a corresponding drop in compressive strength. They also have a nasty tendency to reduce the fire resistance of the mud (and who the hell knows what they do to air entrainment and whether superplastisizers have to be used to even make it finishable)

Any wall can be designed to sustain an impact with any load and I admit I have not watched the video. Chances are though that unless the wall is similar to those designed to house nuclear reactors the concrete will crack and cracks are failure. The amount of force generated by the impact of an HS-20 load stoped near instantly is immense. A 10 wheeler hit a local bridge near where I work (I don't know it's load status). It did 45mph to 0mph in 1 foot. (the deflection of the I-beam it hit). Concrete can take the impacts but it will crack under the impact (I've seen plenty of Precast I-beams hit) unless it has enough mass to sustain the impact without exposing too much of the section to tensile forces. I've seen cast in place single slope barrier with 6 bars on each face (1meter high, half a meter bottom width and 0.100m top width) and hooks at the top busted all to hell from a 20^ impact by what was likely an HS-20 load.

One other thing you should keep in mind, there are other Civil Engineers on this board and some probably have more experience than you do.

its kind of funny actually, because i dont think i know everything and i did just graduate. first, its all intents and purposes, not all intensive purposes, and 2nd, before i posted, i asked our PE some questions regarding this and mixed in his answers with what i already know...i just added in some sarcasm im sorry that you think i dont know what im talking about, and personally i dont really, but most of that wasnt my material. and for the record, while i am at work, i have access to the code books and design parameters which are updated yearly (sometimes biyearly) for any type of engineering you wish to read about. concrete does have tensile strength, just not much, and while it isnt typically accounted for in design, it isnt totally ignored either. i design slabs everyday, and even though i havent been doing it for 30 years, i have learned a thing or two about concrete and i have had the opportunity to actually do some on the job work. obviously i dont have a degree in it so i dont know exactly how an elevated slab routes load or piers can resist 20kips of uplift, but i know how it is designed since that is my job.

i really didnt mean to get in an arguement with anyone, and when i look back at it, i see that i was pretty much taunting you. however, for the record, i dont think i am a post-HS-graduate/pre-degree know-it-all and i will actually admit i know very little. i just know what i have learned this year from my experience at work and i remember a little bit from my materials class i took my senior year in HS at a local college.

p.s. poly fiber in concrete only makes up for like 1.5% of volume, so it doesnt actually hurt the compressive strength that much. post-tension slabs with poly fiber are pre-stressed twice but at half the force, and then they have the full force final stress. i think that is to counter any loss in the compressive performance of that particular mix. of course, they never get 1.5% exactly, so i would say it is anywhere between .75-2.25% (accuracy down here is highly dependant upon the concrete company).

 

[moomoo40moo]

Bandwith Limit Exceeded..... Darn

 

[azncoffeeboi]

bandwith limit exceeded

If somebody sends it to me ill rehost it.

AIM: AznCoffeeBoi

 

[BeauJangles]

New link:
http://www.xmission.com/~knhmeads/barrier.wmv

 

[grrl]

Holy sh*t! That's one tough wall.

 

[arcenite]

Originally posted by: MrDudeMan

Originally posted by: rahvin

Originally posted by: MrDudeMan

so yield is the wrong word. good. next, concrete has tensile strength, but it is only 10% of its compressive strength. you can increase the tensile strength by incorporating polyproylene fibers into the concrete matrix, which also act as crack arresters. what if this wall were in compression? are you forgetting that concrete in compression has much higher resistance to flexure, even in the lateral direction? or are you reading this from a book? at its maximum ductility, concrete with poly fibers and steel mats would hold back a dumptruck while sustaining maybe a few cracks. i doubt it would fracture so badly that there would be a gaping hole in the wall. of course, that all depends on the size, depth, and type of concrete, but most types (if reinforced correctly) would resist this truck.

I realize that you think you know what you are talking about because if I remember correctly you are recently graduated and think you know everything (or even worse are still in college and really think you know everything). For all intensive purposes concrete has no tensile strength and that's a near direct quote from the PCA design book. As you should be well aware those fiberglass fibers you talking about using in the mix drasticly alter the concrete, and mix designs such as that are highly controversial. If I remember correctly the fibers result in an increase in tensile strength and a corresponding drop in compressive strength. They also have a nasty tendency to reduce the fire resistance of the mud (and who the hell knows what they do to air entrainment and whether superplastisizers have to be used to even make it finishable)

Any wall can be designed to sustain an impact with any load and I admit I have not watched the video. Chances are though that unless the wall is similar to those designed to house nuclear reactors the concrete will crack and cracks are failure. The amount of force generated by the impact of an HS-20 load stoped near instantly is immense. A 10 wheeler hit a local bridge near where I work (I don't know it's load status). It did 45mph to 0mph in 1 foot. (the deflection of the I-beam it hit). Concrete can take the impacts but it will crack under the impact (I've seen plenty of Precast I-beams hit) unless it has enough mass to sustain the impact without exposing too much of the section to tensile forces. I've seen cast in place single slope barrier with 6 bars on each face (1meter high, half a meter bottom width and 0.100m top width) and hooks at the top busted all to hell from a 20^ impact by what was likely an HS-20 load.

One other thing you should keep in mind, there are other Civil Engineers on this board and some probably have more experience than you do.

its kind of funny actually, because i dont think i know everything and i did just graduate. first, its all intents and purposes, not all intensive purposes, and 2nd, before i posted, i asked our PE some questions regarding this and mixed in his answers with what i already know...i just added in some sarcasm im sorry that you think i dont know what im talking about, and personally i dont really, but most of that wasnt my material. and for the record, while i am at work, i have access to the code books and design parameters which are updated yearly (sometimes biyearly) for any type of engineering you wish to read about. concrete does have tensile strength, just not much, and while it isnt typically accounted for in design, it isnt totally ignored either. i design slabs everyday, and even though i havent been doing it for 30 years, i have learned a thing or two about concrete and i have had the opportunity to actually do some on the job work. obviously i dont have a degree in it so i dont know exactly how an elevated slab routes load or piers can resist 20kips of uplift, but i know how it is designed since that is my job.

i really didnt mean to get in an arguement with anyone, and when i look back at it, i see that i was pretty much taunting you. however, for the record, i dont think i am a post-HS-graduate/pre-degree know-it-all and i will actually admit i know very little. i just know what i have learned this year from my experience at work and i remember a little bit from my materials class i took my senior year in HS at a local college.

p.s. poly fiber in concrete only makes up for like 1.5% of volume, so it doesnt actually hurt the compressive strength that much. post-tension slabs with poly fiber are pre-stressed twice but at half the force, and then they have the full force final stress. i think that is to counter any loss in the compressive performance of that particular mix. of course, they never get 1.5% exactly, so i would say it is anywhere between .75-2.25% (accuracy down here is highly dependant upon the concrete company).

pwned

 

[Joker81]

Originally posted by: Actaeon
Holy!

Wow, Your Bandwidth got OWNED.

Fixed

 

[simms]

Originally posted by: BlinderBomber
New link:
http://www.xmission.com/~knhmeads/barrier.wmv

Put that on the front...