I have been spending some time researching concrete repairs, specifically repairs of structural members. Meaning, the concrete patch is not only intended to protect the steel but it has to attain the member’s previous structural strength. Iowa DOT has a paper on the subject, “Effective Concrete Repair”
I have also been reading about using fiber reinforced polymers (FRP) to wrap members to contain the concrete and preserve the compressive qualities of the concrete.
In addition, I have been reading about cathodic protection sytems….so I’m thinking, place the cathodic protection, cover with concrete and wrap with FRP.
I can probably name more famous architects than I can engineers, so I will try to improve my education.
born Feb. 6, 1872, Bern, Switzerland.
died April 5, 1940, Geneva
Swiss bridge engineer whose radical use of reinforced concrete revolutionized masonry arch bridge design.
Using very simple construction concepts, Maillart produced some of the most beautiful structures of the twentieth century.
Maillart’s major new forms, the open three-hinged, hollow-box arch, the mushroom slab, and the deck-stiffened arch illustrate at least three of the fundamentally radical ideas he expressed about twentieth century structures.
Architecture is a profession in which design capability is prized and intellectual property is the most common proof of worth, in terms of talent and of experience.
Engineers, not so much. Structural engineers typically don’t seek the limelight, instead believing their work speaks for itself. I believe engineers would be better served (and the profession) if they stood up and demanded the same level of credit, for their work, as Architects.
I think this would raise our profile in the eyes of the general public and increase competition between engineers. Competition may force engineers to greater heights and to raise the bar in designing bridges. I want to be the one given credit for designing a bridge, not the guy who worked on the bridge designed by an Architect. I want the cool guy to be an engineer on that television sitcom instead of an architect…..
I found a bridge blog about the Randolph Bridge Construction. It has some good pictures and has an overview of past bridges. Its cool when people care enough about their local bridge that they create a web page about it.
Well you don’t see this kind of bridge very often.
The British star architect Zaha Hadid has chosen glass fibre reinforced concrete from the Austrian company Rieder to envelope the 275 meters long, “Zaragoza Bridge Pavilion“, the new symbol of the Expo 2008 in the northern Spanish Zaragoza: she has covered the outer skin of the building with 29.000 triangles in different grey shades out of fibreC.
The purpose of the TIG is to identify and champion the implementation or deployment of a select few proven technologies, products or processes that are likely to yield significant economic or qualitative benefits to the users.
I was looking around the web for interesting bridges and I saw this story on the new Pawtucket bridge in Rhode Island.
The only picture I could find is this little rendering.
A) I hate it when little pictures are used, I think it misleads the public as to what the bridge really looks like, and B) I am always disappointed when an Architect designs a bridge. Bridge designers should step up and start providing some interesting designs.
The architecture firm who suggested this design only has houses and building on their website! How can they pivot and become a bridge design firm?
I just wanted to thank the visitors to this site. On average we get about 15 visitors a day with some peaks. I hope to put more ABC details on this site but as you probably know, they are difficult to find….
Okay this is old news but its Sunday and a peaceful waterfall is relaxing. I do think it is interesting to mix bridges and Art. Mr Eliasson (another Dane!) placed a waterfall under the Brooklyn bridge this past summer. The youtube video is here.
Well another post that doesn’t directly relate to ABC bridges but something that most designers have to deal with at some time in their lives, micromanagement. As an engineer I am always improving my technical skills but I also have to think about the business side of bridge design.
One of the most damaging types of management is micromanagement. Not being able to trust your employees can put an enormous strain on your resources and really affect your companies productivity. Some of the most common signs of micromanagement are: (from an article by Charles McConnell)
Cannot delegate effectively or delegate at all
Often hands out only the easy, boring or dirty tasks while delegating nothing of interest or importance
May hand out work, supposedly delegating, but hover instead, providing detailed direction, dictating methods rather than providing proper preparation, making the employee responsible for results and not allowing he or she to figure anything out and learn by doing
Micromanagers are usually irritated when a subordinate makes decisions without consulting them, even if the decisions are totally within the subordinate’s level of authority.
Micromanagement is extremely prevalent and most managers cannot recognize that they are doing it. Unfortunately, in many cases it may be the best option for employees to change their employment as soon as possible.
Since I’m an expert in Context Sensitive design (hey I won an award and everything) I find it interesting when the public gets involved in a bridge design. I have to say, I like it when the passions run high. It means they care about their neighborhood and I think it is up to designers to “prove” their designs are worthy replacements for beloved structures.
I love the quote below concerning the replacement ideas for some new Los Angeles bridges.
“I said as far as I am concerned, if you are going to put this bridge with cables there, you might as well not put a bridge there at all. I would rather not see one there,” said Victoria Torres, a board member of the Boyle Heights Historical Society. “It’s very disappointing when the city is trying to push something on you that you didn’t agree with.”
Kansas has been developing haunched post tenisoned slabs for a while now. While not an ABC type of structure it is a good way to keep the superstructure depth very low. What we are finding in our state are a number of older bridges that don’t meet current vertical or horizontal clearances. The problem is when you want to replace one of these structures and raise the grade, you have spend a lot of money raising the approaching road grade.
If the bridge is near ramps, then you might have to raise the grade on the ramps. Post tensioned slabs help reduce the superstructure height, which in turn helps to add vertical clearance. Post tensioned slabs are just another tool and can help out in certain situations.
I have tried (and will continue trying) to start a non-profit for engineers, called Engineering for Humanity. The idea was to setup a foundation that would allow engineers to give their time and knowledge back to their local community. Engineers could volunteer to build houses or pick up trash but volunteering their knowledge would make the most difference to a community. Maybe not an equal analogy but you don’t ask a Doctor to help build a house. You ask them to donate their skill and education.
Architects have multiple ways to donate their time. For example, Architects for Humanity, has professional architects involved with helping their community through donations of their experience and time.
The two comments I get from engineers about donating their experience is 1) I want to be paid for my help or 2) how will you protect me from liability if I help out. I can’t help with the first one because the whole point is to donate your time and help your local community but I am working on the second one. I am hoping when/if this venture gets off the ground that we could afford liability insurance that would cover engineers when they work in their communities.
I could use some help and this project. If you are interested drop me a line.
The brainstorming meeting produced a number of good ideas about the direction of future bridge research.
ABC topped the list in a number of categories. Everybody seemed to want ABC research on substructures, ABC repair details and ABC barrier rails.
I’m not sure how the ideas get turned into funding but I do think there are a number of places we can start.
Try small details on a number of bridges. For example, a precast abutment on one end of a bridge. Try a spread footing ABC pier. Try using ABC techniques on bridge repairs. How about working with more precast decks, using SCC for repairs and looking at ultra-high strength concrete.
To me ABC is not only building bridges quickly it is a mindset that tries to improve bridge designs and details.
I am going to a brainstorming meeting today to discuss possible research ideas for our state. I think more research into ABC is the way to go. (go figure) The problem is what to research. What elements are amenable to ABC methods.
Bridges are typically slow to build. A massive pier like the one shown below takes a long to build, but is it possible or reasonable to research ABC piers for such large structures?
Steel girders also are slow to install because of all the bolted joints. Would it be possible to develop more ABC sympathetic steel girders? ( I know use rolled shapes..another topic for another day)
Precast decks are becoming more prevalent but most state engineers are still uncertain of their long term survival. Pouring decks take a long time and ABC research into deck designs would probably be the best short term goal.
So what elements of a bridge would lend itself to ABC techniques? Are ABC methods limited to short span bridges? How about an ABC concrete guardrail for TL-3 traffic? Or repair details that allow ABC elements?
I will let you know how the brainstorming session goes but ABC will always have a place in bridge construction.
CNN made a flash map of how the stimulus will help each state in new jobs. It is based on the White House predictions so take it with a grain of salt. It is interesting to see what $787 billion gets you.
I used to live in California and traffic there is insane so I can see the need for ABC in a big way.
Starting in 2008, Caltrans initiated a practice development and implementation for
accelerated bridge construction (ABC). Under the direction of the State Bridge Engineer
(SBE), Caltrans has established a task force that is headed by an ABC Executive
Committee (EC) and Advisory Council (AC) to develop standards, guidelines, and key
policies for implementing structure design for accelerated bridge construction.
Consisting of subject matter experts from design, construction, research, maintenance,
materials, and other relevant fields, the task force outlined a strategic plan to develop,
implement, and promote ABC practice in California.