Stiffness and Damping Ratio of Rubber-Modified Asphalt Mixes: Potential Vibration Attenuation for High-Speed Railway Trackbeds

Abstract

This paper presents the first phase laboratory test results of a research project at the University of Kentucky A number of resonant column tests were conducted to measure the stiffness and damping ratio of rubber-modified asphalt (RMA) samples with different rubber contents and mixed by different methods. The measurements were conducted under a wide range of confining pressures and shear strains to simulate the stress conditions that would be expected in a typical railway foundation. Data from the tests show that RMA has stiffness much higher than compacted soils while providing significantly higher damping ratio than most soils under the same strain level. Therefore, the results from this study indicate that RMA has great potential as a foundation material for high-speed railway trackbeds.