nivek
As Above So Below
All of the above...
All of the above...
3FEL9
Islander
Could be something wrong (not easily detectable on site ) with the concrete mixture from factory,, so they could be innocent,
http://www.concreteconstruction.net/how-to/materials/concrete-durability_o
What’s wrong with strong concrete?
Intuitively, strong concrete should be durable concrete. But it is fundamental in material science that the stronger the material, the more crack-prone it is. If you drop a glass plate, it shatters. But a weak plastic or paper plate doesn’t. .
Last edited:
CasualBystander
Celestial
Could be there is nothing wrong with the concrete mixture so they could be guilty.
Or could be a trifecta of bad design, workmanship, and materials.
Usually everybody has to screw up to create a disaster.
3FEL9
Islander
Huh ? Ever heard that sayin about the chain .. How did it go... something about a link..
nivek
As Above So Below
CasualBystander
Celestial
Well...
Given the amount of reserve strength the bridge should have had, the designers probably cut it a bit close to make it pretty. The workmen probably didn't wet cure it long enough and/or tensioned the cables while it was still soft, etc., because the "fast" design didn't give them enough time, or there may have been an interruption in the pour. The concrete company may not have delivered their best mix because the "bridge" basically just had to support its own weight.
And that is how you create a disaster.
Good designers are conservative and assume everyone else is less than perfect.
3FEL9
Islander
The (my) provided theory was that the concrete was too strong and prone to develop cracks in a short period of time.
Something acc. to the link has been an ongoing trend since the 1940-ties..
A lot of the modern bridges in the U.S have cracks because of the fast curing cement that the industry seem to like...
I dont know.. Just digging... and why is it called ' Portland cement ' ?
CasualBystander
Celestial
3FEL9
Islander
Lake View Drive Bridge Collapse
On December 27, 2005, the Lakeview Drive Bridge collapsed along I-70 in Pennsylvania.
Cracks in the typical "too strong" concrete leading to corossion of reinforcing steel elements and shear keys...
CasualBystander
Celestial
Lake View Drive Bridge Collapse
On December 27, 2005, the Lakeview Drive Bridge collapsed along I-70 in Pennsylvania.
Cracks in the typical "too strong" concrete leading to corossion of reinforcing steel elements and shear keys...
Gee... the reinforcing steel elements of the Florida bridge corroded in a day???
Sounds like a stretch to me.
The concrete that failed on the bridge was operating in compression. The cable tensioners forced the concrete in the bottom chord of the bridge truss - which in theory is in tension to operate in compression. The concrete was just a spacer.
In compression the cracks are irrelevant.
We can simulate a crack in compression by putting two concrete blocks on top each other. You can put as much weight on 2 concrete blocks as you can on just one.
3FEL9
Islander
Liberal Acid rain ? lol
Seriously,,
take your 2 concrete blocks , and put an diagonal crack through the top one... Then apply your load.. Things could slide apart..
CasualBystander
Celestial
You will have to posit a rational for the "diagonal crack". Your link says the cracks are due to shrinkage - which means they will be perpendicular to the direction of the longest dimension.
3FEL9
Islander
Sigh,,
I'm out of my element here 
I donno.. i'll keep an eye on the news from Florida on this one.. And we see what comes up,,,
CasualBystander
Celestial
Sigh,,
I donno.. i'll keep an eye on the news from Florida on this one.. And we see what comes up,,,
Not a civil engineer.
A civil engineer would have a definitive answer. They are the aggregate people.
Civil engineers are responsible for building targets - like bridges and buildings.
3FEL9
Islander
U dont say...Really ?? Any one with sufficient training , knowledge and access could figure out the cause to what really happened.
Dont have to be a civil engineer. Could be an simple ENGINEER or someone with technical interest moonshining into this.
Maybee some McDonalds burger flipping millenial will solve it,, what do I know.
Last edited:
CasualBystander
Celestial
U dont say...Really ?? Any one with sufficient training , knowledge and access could figure out the cause to what really happened.
Dont have to be a civil engineer. Could be an simple ENGINEER or someone with technical interest moonshining into this.
Maybee some McDonalds burger flipping millenial will solve it,, what do I know.
Well...
Not a simple engineer. Simple people aren't good at thinking things through.
A design engineer or someone with practical experience.
They have video of the failure and 900+ tons of evidence.
Not rocket science. Only the legal issues will prevent a quick report on the cause.
nivek
As Above So Below
I'm not a simple engineer but I am an engineer, haven't looked deeply into this bridge debacle but I was driving through the big city 30 minutes from my home and they have 3 bridges under construction, one of which is being completely replaced...As I was driving under each one I thought about this bridge in Miami...Fortunately those 3 bridges haven't fallen....yet...
3FEL9
Islander
I'm a simple engineer.. And Casual implies I cant think things through good enough, compared to his aggregates.
Maybe hes right.. I should stop thinking, and avoid looking into stuff I dont understand..
Cuz theres a real danger I could learn something new. And civil engineers would have to deal with it
Maybe hes right.. I should stop thinking, and avoid looking into stuff I dont understand..
Cuz theres a real danger I could learn something new. And civil engineers would have to deal with it
CasualBystander
Celestial
I'm a simple engineer.. And Casual implies I cant think things through good enough, compared to his aggregates.
Maybe hes right.. I should stop thinking, and avoid looking into stuff I dont understand..
Cuz theres a real danger I could learn something new. And civil engineers would have to deal with it
Well, no.
But if you actually do design (like bridge construction) or work with prestressed concrete structures there are a lot of little details you pick up that aren't obvious. We don't know the actual process of making the bridge so what process failures might have occurred are difficult to speculate on.
Some techniques like steam curing would seem easy to screw up.