Railway Interchange 2019

Sessions Speakers Exhibitors Products Press Releases Floor Plan Buzz

Use of HMA in Rail Track: Inefficiencies and Redundancy of the Present System (Room 101 D)

24 Sep 19
10:30 AM - 11:00 AM

Tracks: AREMA Technical Sessions By Date- Passenger & Tranist, AREMA Technical Sessions By Functional Group- Passenger & Tranist, Technical Sessions By Day- Tuesday

Considering that the adoption of asphalt underlayment has the potential of becoming a standard component of all railway tracked (be it conventional or high-speed or heavy haul), a study was conducted on the current standards and practices for use of asphalt all over the world, which has been presented and published. Several interesting and prominent conclusions were arrived at. This study attempts to create specifications and thickness for the asphalt mix for the underlayment and combination using superpave-mix design in reference to different imposed load. Sensitivity analysis has been carried out between different PG Binder grades, imposed load, aggregate gradation, air voids and seasons with different thicknesses of HMA layer and different models, to predict the most economical and sustainable option. KENTRAK 4.0 FEM model has been used to evaluate stresses, strains and dynamic complex modulus. The complex modulus values peak at around 2% of the void ratio at which the 4” asphalt layer shows excellent performance. Ideally high modulus HMA, a low range PG binder, with void ratio of 2% and aggregate gradation as available, can be used to create a mix which can fulfill all the key performance criteria. Findings also reveal that small thickness of granular subballast combination works better than 8-inch underlayment. Also there is large strength redundancy in the system which can be exploited by adding in sustainable recyclable material (RAP/RAS). This paper is an attempt to propose the resultant findings to regulatory bodies such as AREMA and FRA for their opinion and future incorporation. *Missed this Session or want to view it again? Stop by the VirtualAREMA kiosk located in the Registration area to purchase this product today!