LONG-TERM TRANSFER-LENGTH MEASUREMENTS ON PRETENSIONED CONCRETE RAIL ROAD TIES

摘要

As a part of research study on concrete rail road ties, Sixty (60) concrete rail road ties were fabricated during January 2013 to measure 120 transfer length measurements through a mechanical gage (Whittemore gage). All these concrete ties were fabricated at a PCI certified concrete tie manufacturing plant with 15 different reinforcements that are widely used to manufacture concrete rail road ties all over the world. Variations of strain profiles for these reinforcements are measured after one year to evaluate the long term transfer length measurements. Strain profile measurements are also used to assess the creep in concrete at various cross-sections of concrete rail road ties with different reinforcements. These concrete ties are not subjected to any rail loads over this one year and are kept in two different environmental conditions, thus the primary variable affecting the creep in concrete is cross-sectional area of concrete. Strain growths at various cross-sections of a concrete tie evaluated and presented.