Determining the Health of Prestressed Concrete Railroad Ties

Abstract

Abstract Concrete railroad ties have been a critical component in railway infrastructure for over a century, providing rail car stability and longevity as compared to traditional wooden ties [1]. To ensure the safety of trains traveling upon track structure consisting of prestressed concrete ties, the American Railway Engineering and Maintenance-of-Way Association (AREMA) established standards and guidelines for the design, construction, and maintenance of railway infrastructure, which includes ties as a part of the track structure. To confirm the continued safety of track structures consisting of concrete ties nearing the end of their service life, a comprehensive study was conducted using five different types of tie designs to evaluate the remaining health. This study aimed to provide an understanding of concrete tie degradation and failure modes to determine if the investigated ties that have served the railroad for over 40years can safely remain in service without posing an undue risk to train operations and safety. The experimental methods used in this study included a systematic dissection of the ties, AREMA’s center negative bending and rail seat positive moment tests, and environmental tests. Significant findings indicated that all concrete ties performed adequately in AREMA specified tests, two concrete ties were found to be nearing the end of their service lives due to extensive pre-existing cracks prior to testing. The environmental tests also showed significant degradation to two more concrete ties when they were exposed to freezing and thawing cycles. The last concrete tie, although it was nearing the end of its anticipated service life, was found to maintain its specified strength and performance capability when compared to newer concrete ties. The results of this study provide evidence to support the possible failure modes of prestressed concrete railroad ties which can promote a more reliable railroad system that protects lives, prevent derailments, and ensures the resilience of railroad infrastructure.