Investigation of Material Improvements to Mitigate the Effects of the Abrasion Mechanism of Concrete Crosstie Rail Seat Deterioration

Abstract

Rail seat deterioration (RSD) continues to be identified as one of the primary factors limiting concrete crosstie service life in North America. RSD refers to the degradation of material at the contact interface between the concrete crosstie rail seat and the rail pad that protects the bearing area of the crosstie. Industry experts consider abrasion to be a viable mechanism leading to RSD. A lack of understanding of the complex interactions affecting the severity of abrasion has resulted in an empirical design process for concrete crossties and fastening systems. The objective of this study is to quantify the abrasion resistance of concrete rail seats by using a variety of concrete mix designs and other materials relevant to the rail industry. To simulate the abrasion mechanism of RSD, a small-scale test for abrasion resistance (SSTAR) was designed by researchers at the University of Illinois at Urbana-Champaign (UIUC). Data obtained from the SSTAR will help the rail industry mechanistically design concrete crossties by improving the current understanding of the performance of various concrete abrasion mitigation approaches. Preliminary results show that abrasion mitigation approaches such as the addition of metallic fine aggregates (MFA), steel fibers, and the application of coatings improve the abrasion resistance of concrete specimens.