Neoprene Bearing Pad Slippage at Louisiana Bridges
Publication: Journal of Bridge Engineering
Volume 6, Issue 1
Abstract
Elastomeric bearing pads provide a medium to transfer girder loads to the supporting substructure. Low cost and low maintenance, in comparison with mechanical-type bearings, make elastomeric bearing pads attractive to use. However, some problems have developed with their use. Failure modes for bearing pads include crushing, delamination, and slippage. The most notable of these failure modes is slippage or “walking” out of position. The objective in this paper is to determine the cause of neoprene bearing pad slippage and recommend practical guidelines to remedy the problem. The Louisiana Department of Transportation and Development has experienced bearing pad slippage at some of their prestressed concrete beam bridges. The methods used to investigate this phenomenon included measuring thermal movements and erecting video equipment to monitor bearing pads and traffic simultaneously. In addition, material testing was performed to determine the composition of problematic elastomeric bearing pads. By using time-lapse video equipment, bearing slippage was found to occur on a daily basis. Other findings include that a major number of bearing manufacturers add wax to their neoprene bearings to satisfy AASHTO specifications. As a result of this investigation, the conclusion is that the primary cause of neoprene bearing pad slippage is due to wax materials that are added during pad manufacturing.
Get full access to this article
View all available purchase options and get full access to this article.
References
1.
American Association of State Highway Transportation Officials (AASHTO). ( 1992). Standard specifications for highway bridges, 15th Ed., Washington, D.C.
2.
Arditzoglou, Y. J., Yura, J. A., and Haines, A. H. ( 1995). “Test methods for elastomeric bearings on bridges.” CTR 1304-2, Tech. Rep. for Texas Department of Transportation, Ctr. for Transp. Res., University of Texas at Austin, Austin, Tex.
3.
Chen, R., and Yura, J. A. ( 1995). “Wax build-up on the surfaces of natural rubber bridge bearings.” CTR 1304-4, Tech. Rep. for Texas Department of Transportation, Ctr. for Transp. Res., University of Texas at Austin, Austin, Tex.
4.
E. I. DuPont de Nemours and Company, Wilmington, Del.
5.
English, B. A., Klingner, R. E., and Yura, J. A. ( 1994). “Elastomeric bearings: Background information and field study.” CTR 1304-1, Tech. Rep. for Texas Department of Transportation, Ctr. for Transp. Res., University of Texas at Austin, Austin, Tex.
6.
Hamzeh, O. N., Tassoulas, J. L., and Becker, E. B. ( 1995). “Analysis of elastomeric bridge bearings.” CTR 1304-5, Tech. Rep. for Texas Department of Transportation, Ctr. for Transp. Res., University of Texas at Austin, Austin, Tex.
7.
Iverson, J. K., and Pfeifer, D. W. ( 1985). “Bearing pads for precast concrete buildings.” PCI J., 30(5), 128–155.
8.
McDonald, J., Heymsfield, E., and Avent, R. R. (2000). “Slippage of neoprene bridge bearings.”J. Bridge Engrg., ASCE, 5(3), 216–223.
9.
McDonald, J., Heymsfield, E., and Avent, R. R. ( 1999). “Investigation of elastomeric bearing pad failures at LA bridges.” Tech. Rep. for Louisiana Transportation Research Center, Baton Rouge, La.
10.
Minor, J. C., and Egen, R. A. ( 1970). “Elastomeric bearing research.” NCHRP Rep. No. 109, Transportation Research Board, Washington, D.C.
11.
Muscarella, J. V., and Yura, J. A. ( 1995). “An experimental study of elastomeric bridge bearings with design recommendations.” CTR 1304-3, Tech. Rep. for Texas Department of Transportation, Ctr. for Transp. Res., University of Texas at Austin, Austin, Tex.
12.
Nah, S. H., and Thomas, A. G. ( 1980). “Migration and blooming of waxes to the surface of rubber vulcanizates.” J. Polymer Sci.: Polymer Phys. Ed., 18(3), 511–521.
13.
Roeder, C. W., and Stanton, J. F. ( 1991). “State-of-the-art elastomeric bridge bearing design.” ACI Struct. J., 88(1), 31–41.
14.
Roeder, C. W., Stanton, J. F., and Taylor, A. W. ( 1987). “Performance of elastomeric bearings.” NCHRP Rep. No. 298, Transportation Research Board, Washington, D.C.
15.
Schrage, I. ( 1981). “Anchoring of bearings by friction.” Proc., World Congress on Joint Sealing and Bearing Systems for Concrete Structures, 197–213.
16.
Stanton, J. F., and Roeder, C. W. ( 1985). “Elastomeric bearings design, construction, and materials.” NCHRP Rep. No. 248, Transportation Research Board, Washington, D.C.
Information & Authors
Information
Published In
Journal of Bridge Engineering
Volume 6 • Issue 1 • February 2001
Pages: 30 - 36
History
Received: Sep 2, 1999
Published online: Feb 1, 2001
Published in print: Feb 2001
Authors
Metrics & Citations
Metrics
Citations
Download citation
If you have the appropriate software installed, you can download article citation data to the citation manager of your choice. Simply select your manager software from the list below and click Download.