• Chaudhary, Mohit
• Saboo, Nikhil
• Miljković, Miomir
• Gupta, Ankit

Abstract

Fatigue cracking is one of the primary modes of asphalt deterioration and takes place as a consequence of the accumulation of damage induced by a cyclic stress and strain state. Bituminous mastic, as a distinct phase of asphalt mixtures building up the interfacial transitive zone, plays the most important role in the fatigue-related behaviour of asphalt. Nevertheless, there is still little deep understanding of how the interaction between bitumen and filler affect the fatigue response of mastic. The objective of this research was to investigate the influence of the volume fraction and mineralogical composition of filer on the linear amplitude sweep-based fatigue behaviour of bituminous mastic, as a result of the interaction between bitumen and mastic. This objective was pursued by) quantifying the contribution of filler to the evolution of the comprehensive rheomechanical response of mastic during the testing. The experimental programme comprised one red mud fillerand two carbonaceous fillers (marble and limestone dust) with the volume fractions of 10, 20, and 30 %. The rheological properties of the mastics within the Linear viscoelastic domain were evaluated by frequency sweep. The fatigue behaviour was determined by the linear amplitude sweep including the pseudo strain energy-based viscoelastic continuum damage analysis of long-term aged specimens at the intermediate temperatures of 5, 15, and 25 °C. The results suggested the existence of a threshold of the volume fraction of filler which was supposed to coincide with the optimum film thickness and the optimum interaction between filler and bitumen. The particle size distribution of filler determined the fatigue behaviour of the mastics as indicated by the dependencies of shear stress amplitude, complex shear modulus, and phase angle. The very fine particle size distribution of red mud filler resulted in the particularly high effect of filler particles on the complex shear modulus of mastic during the accumulation of damage which could be explained by the diffusion of bitumen in mineral particles. On the contrary, temperature played the dominant role in the behaviour of marble and limestone dust filler-based mastics. The results demonstrated the critical need of being able to characterise the mode of failure by some of the evaluated rheological or pseudo energy-based quantities, and thus ensure the target mode of failure.

Topics

• impedance spectroscopy
• mineral
• phase
• fatigue
• interfacial