  Sg9018 Member Username: Sg9018 Post Number: 6 Registered: 10-2006 |
According to the Detroit News and WJBK Fox 2 News poor concrete is the reason for bridges problems. MDOT say that 10% of all Michigan's bridges may use the same poor concrete. Each bridge repair cost $500,000. If all the vulnerable bridges were repaired the total cost will be $650 million. WJBK FOX 2 link http://www.myfoxdetroit.com/my fox/pages/Home/Detail?contentI d=2824629&version=2&locale=EN- US&layoutCode=VSTY&pageId=1.1. 1 Detroit News link http://www.detnews.com/apps/pb cs.dll/article?AID=/20070402/M ETRO/704020376 (Message edited by sg9018 on April 02, 2007) | ||
Livernoisyard Member Username: Livernoisyard Post Number: 2942 Registered: 10-2004 |
That lousy concrete was using that good old Zug Island and Dearborn slag. | ||
Charlottepaul Member Username: Charlottepaul Post Number: 731 Registered: 10-2006 |
The state gets what it pays for no doubt. | ||
Rhymeswithrawk Member Username: Rhymeswithrawk Post Number: 601 Registered: 11-2005 |
I figured MDOT just bought Quikrete from Home Depot like everybody else. | ||
Urbanize Member Username: Urbanize Post Number: 525 Registered: 02-2007 |
I heard the story on WDIV or WXYZ also. I thought so too Rhymeswithrawk. | ||
Bulletmagnet Member Username: Bulletmagnet Post Number: 182 Registered: 01-2007 |
Here is an example of a typical Detroit overpass: http://i148.photobucket.com/al bums/s22/bulletmagnet69/kodakg roup032607125.jpg?t=1175556951 | ||
Jimaz Member Username: Jimaz Post Number: 1810 Registered: 12-2005 |
quote:That sounds like a bad approach to an engineering problem. Things aren't supposed to act as predicted. You're supposed to predict how they'll act. Maybe they should design something into the structure that will telegraph that signal. | ||
Gtat44 Member Username: Gtat44 Post Number: 99 Registered: 02-2007 |
Remember when they had to re-do 94 at 75 because of sub par materials? | ||
Dnvn522 Member Username: Dnvn522 Post Number: 226 Registered: 11-2004 |
Oh boy...there's more than a couple of things in that News article that are either completely wrong or misleading. | ||
Club_boss Member Username: Club_boss Post Number: 7 Registered: 12-2006 |
Seems like that was the reason 275 was tore up and re-done. | ||
56packman Member Username: 56packman Post Number: 1185 Registered: 12-2005 |
What were the engineers thinking back then? Were they thinking? This is the same era where they put up all of those steel-trussed bridges and did not paint or coat the steel--the story I heard (which was probably BS) was that the engineering firm was from Texas and their attitude was "it will get a coat of surface rust and stop there and everything will be fine" years later the state is paying Atslantis bros. huge $$$$ to sandblast and paint those trusses baby blue. | ||
Udmphikapbob Member Username: Udmphikapbob Post Number: 300 Registered: 07-2004 |
we should probably cut taxes and cut all the wasteful spending on road repairs... ah, crap...this can't be my 300th post. i was hoping for something more meaningful. oh well, there's always #400. | ||
El_jimbo Member Username: El_jimbo Post Number: 68 Registered: 12-2006 |
wasteful spending on road repairs? have you been on the roads lately? In reality there should be MORE money invested in road repair...not less. | ||
Mcp001 Member Username: Mcp001 Post Number: 2519 Registered: 11-2003 |
I was thinking about suspending the prevailing wage laws and start getting someone who can negotiate a good road guarantee, would be a better place to start. Of course, that's after we can get someone to recreate the concrete formula used on the Davidson back in '41. | ||
El_jimbo Member Username: El_jimbo Post Number: 69 Registered: 12-2006 |
I have heard that one of the problems with concrete right now is that modern concrete uses smaller aggregates than older mixtures and that there is less hard substance for the mix to bond to, thus lessening the durability of the concrete. | ||
Udmphikapbob Member Username: Udmphikapbob Post Number: 301 Registered: 07-2004 |
jimbo, check your sarcasm filter - it seems that it may not be working. | ||
Danindc Member Username: Danindc Post Number: 2288 Registered: 10-2003 |
This is simply bad engineering practice. Why use an experimental material, let alone on a framed, elevated structure such as a bridge? This is why researchers spend time in the lab testing materials--so idiot engineers don't have to do so in the field, with disastrous results. | ||
Defendbrooklyn Member Username: Defendbrooklyn Post Number: 99 Registered: 11-2005 |
Michigan is that dumb...Are we the only state in the union with such terrible leadership across the board? Welcome to Michissippi boys... | ||
Gravitymachine Member Username: Gravitymachine Post Number: 1567 Registered: 05-2005 |
response to the article from my father the civil engineer: quote: | ||
Burnsie Member Username: Burnsie Post Number: 928 Registered: 11-2003 |
M-DOT annual reports from the seventies do state the theory of the "pre-rusted" bridges not needing painting. The repairs on the Lodge bridges from the fifties stem from different (concrete) problems. I suspect that if salt hadn't been used, they'd be in a lot better shape today. Also, if the concrete had been sealed (like what they're getting now-- notice the gray seal/paint on repaired bridges) they would have lasted longer. | ||
Gravitymachine Member Username: Gravitymachine Post Number: 1568 Registered: 05-2005 |
that "pre-rusting" is from cor-ten steel is it not? | ||
Unclefrank Member Username: Unclefrank Post Number: 56 Registered: 03-2006 |
Does the Mafia still control cement here? | ||
Dnvn522 Member Username: Dnvn522 Post Number: 227 Registered: 11-2004 |
quote:Cor-ten is one of the brand names for the material. There is a few different steel types that act in this manner and they weren't only used in Michigan. The most common type used on Michigan bridges was A588 steel from the late '60s through the early '70s. Some of them that do not see much salt are still in relatively good condition. Most deteriorated quickly and either were replaced or painted. | ||
Mercman Member Username: Mercman Post Number: 13 Registered: 10-2006 |
Quote: "It's unclear why the state experimented with the aggregate concrete. Smith and Collins said it's more expensive than other concretes. Smith said the aggregate was one of three types approved by the state following a battery of tests. It was discontinued because it caused potholes and crumbling decks." Costs more and doesn't work as well...Hmmm. | ||
Rampartstreetnorth Member Username: Rampartstreetnorth Post Number: 42 Registered: 07-2006 |
The Romans got it right. Some Roman structures built of concrete are still standing after nearly 2,000 years, and in spite of not using steel or iron reinforcing rods. http://www.djc.com/news/co/111 33038.html | ||
Danindc Member Username: Danindc Post Number: 2297 Registered: 10-2003 |
quote: The Romans also used different design approaches, though. Typically, their structures were supported primarily in compression (think arches), thus tensile capacity was a nonfactor. Even where beam elements spanned between two supports, such as at the porticos, the spans were short enough where shear--not flexure--was the governing failure mode. | ||
Bob Member Username: Bob Post Number: 1425 Registered: 11-2003 |
Michigan did a lot of experimenting with road construction in the boon days of old. During those times we were on the cutting edge of highway engineering, thanks in part to having a lot of the prototype highways since we were the area that put the world on wheels. We had money to burn then and they did a lot of experimenting with different highway designs and materials. 275 and 696 east of 75 were examples of this. They tried experimental techniques that lead to big cracks in the concrete, which is why they were so bad for some many years. There was not a lot of long term planning going on, and they figured we would always have the money to fix it if it did not work. Well, the rest of the world learned from our highway designs how to make them better, which is why we have those dangerously small acceleration and deceleration ramps on 94. Now our state is no longer on the cutting edge of anything and we do not have money even take care of what we have. How far the mighty have fallen. | ||
Burnsie Member Username: Burnsie Post Number: 929 Registered: 11-2003 |
The pre-rusted steel was used into the late '70s on I-475 bridges in Flint. I believe they're still unpainted | ||
Dnvn522 Member Username: Dnvn522 Post Number: 228 Registered: 11-2004 |
You're correct. That was the last corridor done with the weathering steel, in '76 and '77. | ||
El_jimbo Member Username: El_jimbo Post Number: 73 Registered: 12-2006 |
The Romans didn't have 82 tons of semi truck driving over their roads 13,000 times a day. |
