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Description: A Cooperative Slab Track Research and Demonstration Program for Shared Freight and High Speed Passenger Service research and demonstration program was initiated by the Portland Cement Association (PCA) to advance concrete slab track technology and to demonstrate the capability of slab track to provide a low maintenance and safe track structure on track shared by high-speed and freight trains in the United States. This program includes the development of design methodology, design of the slab track test sections, preparation of a slab track recommended practice design guide, life cycle cost studies, laboratory tests, and field tests. The slab track laboratory test program was designed to test and evaluate two types of slab track. One type using direct fixation fasteners mounted to the top surface of a concrete slab. The second type using concrete blocks with rubber boots and pad embedded in recesses in the top of a concrete slab.
This report only covers the laboratory test program. The two types of slab track, direct fixation slab track (DFST) and independent dual block track (IDBT), were constructed on top of a thick rubber pad to simulate the subgrade. Each type of slab track was subjected to static loads and 3 million cycles of repeated loads which simulated the train load conditions (315,000 pound freight cars) at the Transportation Technology Center High Tonnage Loop. During the test, freight car wheel loads were simulated by the use of hydraulic actuators and applied to the top of rail. Also, endurance and stiffness tests were conducted on the rail fastener system for each type of slab track.
The report describes the slab track specimen tested, the test setup, instrumentation, and test results. Both types of slab track met predicted expectations and performed well during the static and repeated load tests. There was fairly good agreement between the measured behavior of the slab track and the calculated behavior of the slab track from structural analysis of the slab track.
The slab track is now being tested under actual service conditions at the Transportation Technology Center High Tonnage Loop in Pueblo, CO with funds provided by the Federal Railroad Administration. This report is also found on DVD021.
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