Breakage and shape analysis of ballast aggregates with different size distributions--颗粒学报PARTICUOLOGY

Sun, Y., & Zheng, C. (2017). Breakage and shape analysis of ballast aggregates with different size distributions. Particuology, 35, 84-92. https://doi.org/10.1016/j.partic.2017.02.004

Breakage and shape analysis of ballast aggregates with different size distributions

Yifei Sun ^{a b}, Changjie Zheng ^c *

a Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering, College of Civil and Transportation Engineering, Hohai University, Nanjing 210098, China
b School of Civil, Mining and Environmental Engineering, University of Wollongong, Wollongong, NSW 2522, Australia
c Key Laboratory of New Technology for Construction of Cities in Mountain Area, Ministry of Education, School of Civil Engineering, Chongqing University, Chongqing 400045, China

10.1016/j.partic.2017.02.004

Volume 35, December 2017, Pages 84-92

Received 15 December 2016, Revised 6 February 2017, Accepted 12 February 2017, Available online 12 June 2017, Version of Record 30 November 2017.

E-mail: zcj_89@163.com

Highlights

• Breakage behavior of ballast aggregates under monotonic and cyclic triaxial tests was studied.

• Effect of particle size distribution and density on ballast breakage behavior was investigated.

• Marsal's breakage index worked well for aggregates with multi-initial gradings.

• The higher the load frequency, the more regular the particle shape will be under cyclic tests.

Abstract

Particle breakage usually alters the size and shape of ballast aggregates, which significantly influences the long-term performance of rail tracks. This study reports an investigation on the breakage and shape characteristics of ballast aggregates subjected to monotonic and cyclic triaxial tests with two different load frequencies. The results show that particle breakage is not only influenced by the particle size distribution but also by the relative density. Breakage indices defined by breakage potential and grading entropy fail to characterize the breakage extent of ballast with multiple initial particle size distributions, while the Marsal breakage index exhibits a general decrease with increasing coefficient of uniformity for ballast with similar relative densities. Higher breakage extent is observed in ballast subjected to a higher load frequency. Particle shape varies with load frequency because of breakage. A slightly higher value of each shape index is observed for ballast subjected to a higher load frequency, implying that ballast aggregates become increasingly regular with the increase of load frequency.

Graphical abstract

Keywords

Breakage; Breakage potential; Grading entropy; Particle shape; Ballast

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