Abstract
Two of the main problems encountered in flexible pavements are the stripping of coarse aggregates and the formation of rut depth due to increases in the volume of road traffic and heavy vehicle loads, especially in areas where speeds are low. The existence of rut depth also affects the comfort and safety of road users due to the water accumulation on the pavement surface and reducing tire/pavement friction, which can lead to hydroplaning phenomena. In this research, it was proven that the use of fillers of different origins influences the affinity between aggregates and the binder. The effect of an adhesion promoter in the mix design (such as the amine included in cellulosic fiber pellets) was also studied. Several tests were carried out to determine the binder/aggregate adhesiveness, water sensitivity and resistance to permanent deformation, to evaluate the performance of different blends. It was found that the addition of this additive increased 10% of the aggregate surfaces covered with bitumen when compared with the aggregates without this addition. As expected, the water sensitivity tests showed that the mixture with granitic filler had the lowest indirect tensile strength ratio (ITSR) value (70%), while the mixtures with limestone filler led to the highest percentages (ranging from 83 to 93%). As for the results of the wheel tracking tests (WTT), it was confirmed that the use of limestone filler translates into an improvement in the performance against the permanent deformation of the asphalt mixtures. The mixture with higher bitumen content and adhesion promoter revealed the best average results.
Highlights
Over the past few decades, road administrations around the world have become aware of the importance of extending the life cycle of asphalt mixtures included in different layers of road pavements
This paper describes in some detail all materials used in the aforementioned research; the samples preparation; the test equipment, its configuration and procedures; as well as the results obtained and some conclusions that can be inferred
After 24 h of testing, the mixture with the additive was higher by 23% (53 against 43%), confirming the effect of the adhesion promoter and the trend observed by Porot et al [47], who concluded that the rolling bottle test begins to be truly differentiating after this period
Summary
Over the past few decades, road administrations around the world have become aware of the importance of extending the life cycle of asphalt mixtures included in different layers of road pavements. Where there is a great availability of granitic aggregates, it is essential to study the influence of their affinity with different binders. The stripping phenomenon in asphalt mixtures is one of the most important types of distress in flexible pavements [2]. The affinity between aggregate and bitumen is described by four theories, isolated or combined [3]: molecular arrangement, mechanical adhesion, surface energy and chemical reaction. Several factors affect these theories, namely: chemical composition of materials; viscosity of bitumen; texture, angularity, shape, porosity and cleaning of aggregates; surface tension in the interface of bitumen–aggregates; and temperature in the mixing or the presence of moisture
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
