In order to quantify the effect of different reinforcement types on transfer lengths, an extensive study was conducted with the selected group of twelve different reinforcement types. These reinforcements are extensively used to produce concrete railroad ties across the world. These employed twelve (12) different types are of 5.32 mm diameter wires with different surface indent geometries. A research team from Kansas state university visited a PCI certified concrete tie manufacturing plant during January 2013. During the plant visit, four (4) concrete railroad ties were cast for each reinforcement type for a total of 48 ties. Considerable part of the study conducted at the plant was previously published by the authors. However for effective understanding, brief explanation of the tie manufacturing process will be presented in this paper. Strain measuring points were mounted on the bottom surface of a concrete railroad tie during the casting process. Proper measures were taken to safeguard these strain measuring points during loading. Transfer lengths were calculated using these mounted strain measuring points. Transfer length measurements were calculated at the plant, immediately after the application of prestressing forces to the concrete ties. After the casting process, two ties for each reinforcement type were stored at plant location for approximately one year and the remaining two ties (companion ties) for the each reinforcement types were shipped and stored at Kansas state university. Transfer length measurements were again calculated at this stage for all 48 ties. Ties stored at plant location were later subjected to cumulative in-track railroad loading of 85 million gross tons over six (6) months period of time. Whereas, the companion ties stored at Kansas state university were not subjected to any loading. Transfer lengths are calculated and compared at this stage and presented [4] in the past.

Ties which were already subjected to 85 million gross tons were further loaded to cumulative total of 236.3 million gross tons and the companion ties stored at Kansas State University were not subjected to any loading. Transfer lengths for the ties (twenty four) that were subjected 263.3 million gross tons were calculated and presented in this paper with detailed explanation. Transfer length behavior under different magnitudes of loading is also presented along with the discussion.

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