Proposal of a Qualification Test for Insulated Rail Joint

The American Railway Engineering and Maintenance-of-Way Association (AREMA) Manual for Railway Engineering (MRE) recommends qualification tests for glue-bonded insulated rail joint e.g., longitudinal compression test, rolling load test, electrical resistance test etc. However, despite successfully passing the longitudinal compression load and rolling load test, observations on railways have revealed that during cold weather, the high tensile forces can surpass the bonding strength of joint bars in a field-fabricated glued insulated bonded joints. This can result in a gap of up to 1.5 mm or more, leading to battered rail ends that contribute to high dynamic load,  noise and/or electrical conductance issues. Some standards e.g., Australian standard specifies pull-apart test; this standard do not specify longitudinal compression test as is recommended in MRE manual. For at least two reasons, pull-apart test may be more appropriate than a longitudinal compression test to assess the adhesion or cohesion strength of epoxy against failure for evaluating the joint quality. The pull-apart test's load and acceptance criteria are suggested. AREMA may consider reviewing its qualification tests to incorporate the pull-apart test alongside the existing ones or replacing the longitudinal compression test load with the pull-apart test.