April 17, 1997
FATIGUE TESTING OF
DECK-TO-DECK DOWELED CONNECTIONS IN HARDWOOD GLUED LAMINATED BRIDGE DECKS
by:
The Pennsylvania State
University
The National Timber Bridge Initiative was started in 1989 to encourage the use of wood in bridge construction. The purpose of the initiative was to boost the economy of the forest industry and increase profits for wood processors. Pennsylvania has an abundant supply of hardwoods such as Red Maple, Yellow Poplar, and Northern Red Oak. Therefore, PennDOT began a research program to develop a hardwood bridge design. Much of the design ahs been completed by the Agricultural and Biological engineering and Forest Resource Departments at Penn State under the supervision of Harvey Manbeck, John Janowiak, and Paul Blankenhorn. Performance testing (monotonic load testing and fatigue testing) has also been conducted for deck to beam connections. However, fatigue testing of the deck to deck dowel connections recommended in the design has not been completed. Fatigue can cause deterioration of deck joints to the point where they can no longer serve their purpose to transfer loads between deck panels. Cyclic loading can lead to a loss in joint stiffness and increased differential defection between adjoining deck panels. This seminar will outline the preliminary results of recent fatigue tests of deck to deck dowel connections conducted in the Agricultural and Biological Engineeirng Department structures lab at the Pennsylvania State University.