Authors: Jerry G. Rose, E. Ray Brown, Monica L. Osborne

Date of Publication:  2000 (?)

Sponsoring Agency:  U.S. Transportation Research Board, Committee on Railroad Track Structure System Design

Performing Organization:

Report No:

Abstract:

The evolution of hot-mix asphalt (HMA) trackbed technology is documented as presently practiced in the United States. Criteria used in selecting sites for and the attendant benefits of HMA trackbeds, based on long-term performance evaluations, are discussed. Prevailing practices
for selecting ideal HMA mix parameters, trackbed section designs, and application procedures are described in detail. Primary attention is directed at the “underlayment” procedure in which the HMA serves as a premium subballast layer within the track structure to enhance the support, waterproofing, and confinement properties of the subballast. The roadbed or subgrade materials underlying the HMA mats maintain near-optimum moisture content. The HMA appears to undergo little if any weathering or deterioration in the trackhed environment. The resultant benefits are decreased maintenance costs, fewer slow orders, fewer operational interferences, and improved operational efficiency of the rail network overall.
 

No. of Pages:  9