Structural Behavior of Rail Fastening System Used for Recycled Plastic Composite Crossties

Currently, the railroad industry is leaning towards alternative solutions to hardwood timber for crossties applications. This trend is part of an effort to increase train speeds beyond the wooden crossties capacity and minimize the negative environmental effects associated with them. Among the available alternatives are recycled plastic composite crossties. Their sustainably, environmental benefits, durability performance and ease of installation or one to one replacement of timber crossties render them an attractive and competitive solution. Several research programs have studied this material in the past. However, additional research is required to fully understand the behavior of these materials. This study aims to investigate the performance of fastening system used for recycled High Density Polyethylene crossties. The study encompasses comprehensive experimental investigations and analytical finite element modeling. The testing program evaluated each of the fastening system components using static test methods recommended by the AREMA manual. These tests addressed the spike pullout and lateral restraint for both screw and cut spikes as well as the fastening system uplift behavior. Moreover cyclic testing was also conducted on the full system to study the interactions of the fastening system components with the plastic composite crosstie. Finite element models were constructed and calibrated using the experimental data in order to extrapolate on the experimental results and predict different scenarios. The results observed in this study showed great promise highlighting the potential of these material if properly optimized and engineered.