Parsons Brinckerhoff, Inc (now WSP) engaged CTLGroup to conduct tests on the proposed concrete ties and complete direct fixation fastener assemblies to be used for the Chicago-St. Louis High Speed Rail Project. These tests were part of the upgrades and improvements to the rail line between Chicago and St. Louis to accommodate high-speed Amtrak trains. Tests were conducted in accordance with the Concrete Tie Manufacture QA/QC Documentation and American Railway Engineering and Maintenance of Way Association (AREMA) Chapter 30, Testing of Monoblock Ties.
Ties
A number of AREMA Chapter 30 tests were conducted and the test results were summarized in a final report. The test specification loads and spans were in accordance with Union Pacific Railroad Company Concrete Tie Specification. Structural cracking was defined as a crack, visible with a 5X-power magnifying glass, extending from the tensile face to the bottom of the nearest level of pre-stressing wires. Two concrete ties were submitted for AREMA Test 6 – Wear and Abrasion Testing. Both of the ties completed 5 million load cycles. At the completion of 5 million cycles, both ties were able to support an actuator load of 70 kips without exceeding the maximum railhead deflection of 0.20 inches.
CTLGroup also provided Petrographic and air-void system analysis as part of the tie evaluation.
Fastening System
The fastening system met the Vertical Load, Vertical Uplift, Lateral Load, Longitudinal Restraint, Voltage Withstand, Electrical Resistance and Impedance, Dynamic to Static Stiffness Ratio, Vertical and Lateral Repeated Load and Repeated Load Test with One Anchor Bolt Tests specification requirements. Both of the fastening systems withstood the 3,000,000 pound cycle repeated load, 15,000 cycle repeated load tests with one anchor bolt, and static load tests without any visible failures or damage.
