Image analysis for morphology, rheology and degradation study of railway ballast: A review

The performance and deformation of ballast bed are significantly influenced by the particle morphology (size and shape), the rheology (translation and rotation), and the degradation (breakage and abrasion). Regarding the ballast particle morphology, the ballast particle size is generally measured by sieving and described with the Particle Size...

Chemical and Rheological Evaluation of Aged Lignin-Modified Bitumen

As bitumen oxidizes, material stiffening and embrittlement occur, and bitumen eventually cracks. The use of anti-oxidants, such as lignin, could be used to delay oxidative aging and to extend the lifetime of asphalt pavements. In this study, the chemical and rheological effect of lignin on bitumen was evaluated by using a single dosage organsolv...

Ageing effect on chemo-mechanics of bitumen

Ageing has a significant impact on the chemical and mechanical behavior of bituminous materials. In this study, Fourier Transform Infrared (FTIR) spectrometer and Dynamic Shear Rheometer (DSR) tests were utilized to investigate the effect of ageing on the chemical and mechanical properties of bitumen. Bitumen films with thickness of 2 mm were...

Ballast degradation: Effect of particle size and shape using Los Angeles Abrasion test and image analysis

Ballast track is the most widely used track for the railway transport, and ballast bed plays a significant role to provide resistances during train operation. Generally, the ballast bed consists of crushed stones. To achieve the mitigation of ballast degradation, the first priority is to describe the degradation development and to study its...

Ageing effect on the relaxation properties of bitumen

The ageing of bitumen has a significant impact on the mechanical behavior of asphalt concrete. In this study, Dynamic Shear Rheometer (DSR) tests were utilized to investigate the effect of ageing on the relaxation properties of bituminous materials. PEN 70/100 bitumen films with thickness of 2 mm were exposed to laboratory ageing at various...

Chemo-mechanics of ageing on bituminous materials

Ageing of bitumen is a complex process. It is accompanied by major chemical and mechanical changes. In this study, Fourier Transform Infrared (FTIR) spectrometer and Dynamic Shear Rheometer (DSR) tests were utilized to investigate the effect of ageing on the chemical and mechanical properties of bituminous materials. Bitumen films with thickness...

The effect of ageing on chemical and mechanical properties of asphalt mortar

Asphalt mortar is a mixture of bitumen, filler, and sand. Mortar plays an important role in asphalt mixtures as it serves as the adhesive between the coarser aggregates. Due to the effect of bitumen ageing, the chemical and mechanical properties of asphalt mortar evolve with time. The mortar becomes more brittle and prone to cracking, thus...

Experimental and computational investigation of gas diffusion in bitumen

When oxygen diffuses in a bituminous film, it also reacts, simultaneously, with the constituents of the bitumen and as such it is gradually depleted. This depletion process masks the characteristics of the actual diffusion process and complicates the determination of the diffusion coefficient needed for computation of oxygen concentration and...

A fully coupled ship motion and sloshing analysis in various container geometries

A Hybrid Five-Point Finite Difference Scheme for Convection-Diffusion Equations

In this paper, some five-point finite difference schemes for steady convection-diffusion problems are presented. To begin with, we use the finite volume method (FVM) to discretize the convection-diffusion equation. After that, we present two five-point difference schemes for the approximation of the first order derivatives on faces, one of which...

Surface charge accumulation in SF6: Mechanisms and effects