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MPC Research Reports
Report Details

Title:Effects of Environmental Exposure on Timber Railroad Bridge/Track Members and Connects
Authors:Richard M. Gutkowski, Travis Burgers, and Jeno Balogh
University:Colorado State University
Publication Date:Dec 2004
Report #:MPC-04-167
Project #:MPC-194, MPC-160
TRID #:00986798
Keywords:bridge decks, deflection tests, humidity, load factor, railroad bridges, steel rails, temperature, timber construction, trestles, wood ties


This report describes the results of examining the effects of weather exposure conditions on the connection details of the open deck timber trestle bridge. As an exploratory experimental study, the time dependent mechanical effects of moisture, temperature and humidity on a particular connection detail was observed. A full scale specimen, including the standard interconnections of the steel rail to wood cross tie to multi ply chord member, was constructed. The specimen was then exposed to extremes of temperature and humidity on an accelerated time basis over 2 to 3 months. An environmental chamber was used to create the desired exposure conditions. At selected times, the conditioned specimen was removed and subjected to a flexural load test. The change in deflection and load sharing was observed via physical measurements. Although the deflection changed measurably, the load sharing between the plies of the chord remained essentially the same.

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