Fatigue Resistance of Bituminous Mixtures and Mortars Containing High Reclaimed Asphalt Content.

Johan Blom,Alexandros Margaritis,Wim Van Den Bergh,Geert Jacobs,Georgios Pipintakos

doi:10.3390/ma13245680

Johan Blom, Alexandros Margaritis + Show 3 more

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https://doi.org/10.3390/ma13245680

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Abstract

With the increased use of reclaimed asphalt (RA), the ability of bituminous materials to resist fatigue cracking may face a decline mainly due to the aged reclaimed asphalt binder (RAB), especially when RA is used at higher rates and not sufficiently treated. In this study, the bulk scale (asphalt) and its subscale (mortar) were employed to evaluate the effect on fatigue resistance when a RAB is added, by considering three replacement rates: 0%, 40%, and 70% RAB. The fatigue testing of asphalt mixtures was carried out using a four-point bending (4PB) setup, while the mortars were tested using a new column-like geometry utilising a dynamic shear rheometer (DSR). The fatigue properties were further analysed using dissipated energy concepts. The aim of this study was, first, to assess whether the inclusion of a RAB can provide at least similar fatigue properties compared to an all-virgin mix, and second, to evaluate whether the proposed treatment is beneficial for the mixtures with a RAB. The asphalt tests revealed that the inclusion of a 40% RAB led to increased fatigue resistance, whereas the mortar tests showed that the inclusion of RAB has an inverse effect on fatigue life.

Highlights

At present, asphalt recycling is prevalent within the road construction industry because it is accepted as a sustainable approach
The mixtures with reclaimed asphalt binder (RAB) showed a gradually small decrease in |E*|, as frequency increased. It observed that the 70% RAB mix shows the highest deviation compared with the rest, and this can be can be observed that the 70% RAB mix shows the highest deviation compared with the rest, and this attributed to the high replacement rate, which induces a certain variability
The observed can be attributed to the high replacement rate, which induces a certain variability

Summary

Introduction

Asphalt recycling is prevalent within the road construction industry because it is accepted as a sustainable approach. The economic and environmental benefits of using reclaimed asphalt (RA) are widely accepted, questions arise from the construction sector concerning the service life of asphalt mixtures with RA. Concerning the effect of RA on the performance of asphalt mixtures, one of the main engineering problems associated with the inclusion of RA in base layer asphalt mixtures is fatigue cracking [3,4,5,6]. The focus of this study will be on the cracking done at intermediate temperatures or known as fatigue cracking. This type of cracking initiates when excessive tensile strains develop at the bottom of the asphalt layer leading to crack initiation [7]

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