There has been an on-going discussion on a historic bridge listserve maintained by Eric Delony on the maintenance of reinforced concrete arch bridges. I have pulled some of the reference materials noted in this discussion and list them below. I have also added to the Resource Library a PDF of the National Park Service's Preservation Brief 15, Preservation of Historic Concrete, which you can get free from NPS, though it is currently not available on-line.
Second edition, Frederick W. Taylor and Sanford E. Thompson, A Treatise on Concrete Plain and Reinforced (New York: John Wiley & Sons, 1909)
Second edition, George A. Hool, Reinforced Concrete Construction, Vol. I, Fundamental Principles (New York: McGraw-Hill Book Company, 1917)
Conservation of Bridges, G. P. Tilly, Alan Frost, Jon Wallsgrove, Gifford and Partners
Edition: illustrated, Published by Taylor & Francis, 2002
ISBN 0419259104, 9780419259107, 404 pages.
“A practical guide that provides essential guidance and recommendations for bridge conservation, repair and maintenance strategies. Highway, foot, railway, river and canal bridges built before 1966 in a variety of construction materials are covered. A new approach to the best practice of conservation of bridges is proposed, and issues such as the value of retaining existing structures and following the good practice developed through experience are discussed. The book illustrates what has, and what can continue to be achieved, in the pursuit of excellence in this field. It is essential reading for all bridge engineers.”
Terry H. Klein, SRI Foundation
The authors of NPS Bulletin 15, Deborah Slaton and Paul Gaudette, Wiss, Janney, Elstner Associates Inc. have also written several articles for the Journal of Architectural Coatings that address potential problems with sealers and coatings on historic masonry structures and how to remove old coatings, including graffiti. Painting, coatings and graffiti tags are real challenges for restoring concrete bridges. These articles are excellent references.
I have a practical question to ask about concrete arch bridges. I am the historic bridge cooridinator at the Arkansas Highway Department who along with the Heavy Bridge Engineer are trying to figure out the best solution to a problem with one of our concrete arches. The problem is that it appears that the parapet walls that contain the fill for the road are begining to detach from the arch and slide off. The bridge was built in the mid 1920s and resembles the arches built by the Luten Bridge Company, but was built by a local contractor. We do not have the plans for the bridge due to the fact that it was built by one of our counties, but we had some plans drawn by Luten for a similar bridge in another part of the state. We thought that they could be useful, but they haven't really helped. So, has anyone encountered this type of problem or do you have any ideas that would help us. The few things we have discussed are rods for the full length of the bridge with plates on the outside to try to hold the fill material on the arch and removing the parapet walls and anchor a new wall to the arch, neither one of these sounds very good.
Thanks
Robert Scoggin
Robert -
I suspect you are finding that there are several ways to deal with this bridge. Deciding which is the best requires an evaluation of the specifics - size, location, extent of the problem, and the sensitivity of the site to the solution (that is, visible anchor plates versus replacement of the original concrete). The traffic volume and ability to close the bridge for repair may weigh into a choice. In what condition is the remainder of the bridge?
Is there a way to post photos of the bridge in this forum? If not, perhaps you can e-mail photos to those of us interested in commenting on your project.
Regards,
John Hinman, PE, SE
CH2M HILL
Amy -
Can you provide a specific reference to the articles? This is a significant subject!
John Hinman
John, thanks for responding. You are right there are several ways to go here. Here are some specifics on the bridge; it has three arches 85 feet long with the total bridge length of 291 feet, it's setting is rural on a state highway spur and has an average daily traffic of 750 vehicles. I am not sure if they will let me post some picutres in the resource library, but if you send me your email I will send what pictures I have.
Bob
Robert W. Scoggin: John, thanks for responding. You are right there are several ways to go here. Here are some specifics on the bridge; it has three arches 85 feet long with the total bridge length of 291 feet, it's setting is rural on a state highway spur and has an average daily traffic of 750 vehicles. I am not sure if they will let me post some picutres in the resource library, but if you send me your email I will send what pictures I have. Bob
Bob -
Feel free to send photos to jhinman@ch2m.com. No promises, but perhaps I can throw an idea or two on the table.
John
Bob,
It is okay to post photographs of the bridge in the Resource Library section of the website. Get back to me if you have any problems posting the photos. It is pretty straightforward.
And when you post the photos in the Resource Library, go back to this discussion thread and post that you have placed the photos in the Library. That way, everyone will know that the photos are there. Thanks!
I have posted the pictures of the arch bridge in the Resource Library in the form of a pdf. The file is named Arkansas Arch Bridge Photos.
Hi Robert:
If I understand your question you have a situation wherein the spandrel walls that retain the fill on top of the arch are moving. If this is the case we have seen this many times and it is due to poor draining fill over the arch. When these arches were built, positive rainage was not installed, but rather weep holes (if they were at all). Over the years water has infiltrated , the weep holes if built are not functioning , and the saturated fill is pushing the walls out. You know if you have a moisture problem by looking at the condition of the underside of arch.
As far as a fix is concerend, the best way (but the most painful, economically) is to remove the fill, repair the top of arch (that probably is deteriorated due to the saturated fill), install a waterproofing membrane over the arch, positive drainage, clean fill and rebuild the spandrel walls. We have looked at installing tie rods, but i don't believe you can put enough in to counteract the pressure of the fill and you really have not solved the problem that caused the movement in the first place.
I hope this helps. If you have some photos and can post them it would be helpful for all to see the situtation
Joe Pullaro
Regarding Joe's response to Bob's arch bridge issues, I agree with what Joe said. The basic mechanics of the spandrel walls is simple. A person might ask why it took so long to become evident.
Joe's suggestion for a fix is the most straight-forward and robust approach. There are some variations and options that might be considered, though. One of these is to preserve the existing spandrel walls. This may be easy or it may be difficult, depending on the degree of deterioration and the specific details of the walls, but it will preserve the appearance and the fabric of the bridge. Note the board forming, and the continuity of the forming from the spandrel walls to the sides of the arch. That will be difficult to reconstruct.
An approach to preserving the spandrel walls might include replacing the earth fill with cellular concrete. This can reduce or eliminate the soil pressure on the spandrel walls, which will probably not figure for lateral loads from soil plus moisture plus live loads. The cellular concrete can support the walls, instead of the other way around. (It's not really that simple, but that is the basic idea.) Arch repair and drainage, as Joe described, is still necessary.
Another approach is to maintain the existing spandrel walls and to build new spandrel walls at the interior. The original spandrel walls become almost a veneer.
These ideas don't necessarily reduce the project cost, but may preserve portions of the original bridge.
I'm not disagreeing with anything Joe said. My comments are simply observations of some options. Whether they are worth pursuing is a value decision the owner must make.
Thank you to both John and Joe for your responses. I agree with both of you. Joe I have uploaded a few pictures of the bridge to the resource library. They are in pdf format and are named Arkansas Arch Bridge Photos. I am going to talk to the Heavy Bridge Engineer and see if we can make this project a full fledged rehab instead of just a repair job.
Here are citations. These are great sources for dealing with coatings and graffiti on concrete bridges:
Connolly, James D., Paul E. Gaudette and Deborah Slaton. "Concrete: To Coat or Not to Coat," The Construction Specifier (March 2000): 72.
Connolly, James D., Leonard L. Phelps and Deborah Slaton. "Sealers and Coatings for Masonry and Concrete: The Essentials," Journal of Architectural Coatings (January 2006): 34-41.
Freedland, Joshua and Deborah Slaton. "The Writing on the Wall," The Construction Specifier (May 2006): 122.
Gaudette, Paul E. and Deborah Slaton. "Making the Call on the Concrete Wall," Journal of Architectural Coatings (June/July 2008): 32-37.
Slaton, Deborah. "Peeling Away the Years: Taking on the Job of Getting Old Coatings Off," Journal of Architectural Coatings (March/April 2007): 60-63.
Slaton, Deborah. "Coatings and Historic Structures: A Preservation Dichotomy," Journal of Architectural Coatings (October/November 2006): 24-31.
Amy Squitieri: Here are citations. These are great sources for dealing with coatings and graffiti on concrete bridges: Connolly, James D., Paul E. Gaudette and Deborah Slaton. "Concrete: To Coat or Not to Coat," The Construction Specifier (March 2000): 72. Connolly, James D., Leonard L. Phelps and Deborah Slaton. "Sealers and Coatings for Masonry and Concrete: The Essentials," Journal of Architectural Coatings (January 2006): 34-41. Freedland, Joshua and Deborah Slaton. "The Writing on the Wall," The Construction Specifier (May 2006): 122. Gaudette, Paul E. and Deborah Slaton. "Making the Call on the Concrete Wall," Journal of Architectural Coatings (June/July 2008): 32-37. Slaton, Deborah. "Peeling Away the Years: Taking on the Job of Getting Old Coatings Off," Journal of Architectural Coatings (March/April 2007): 60-63. Slaton, Deborah. "Coatings and Historic Structures: A Preservation Dichotomy," Journal of Architectural Coatings (October/November 2006): 24-31.
Thank you for posting these, Amy!