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1 June 2016
thumbnail The use of hydrated lime in the formulation of asphalt mixtures.jpg

Article prepared for the 6th Eurasphalt and Eurobitume Congress in Prague June 2016

Authors: Didier Lesueur, Christophe Denayer, Hans-Josef Ritter, Christof Kunesch, Slawomir Gasiorowski, Alberto d'Alto

ABSTRACT

Hydrated lime is being increasingly used in Europe as a multifunctional additive for asphalt mixtures. Reasons for this have been thoroughly reviewed and explained in recent years, showing that the main benefits lie in the improvement in resistance to moisture damage, slowing-down of bitumen aging and improved mechanical properties. These combined effects lead to an increased durability of the mixtures. In this paper, examples are given of how these functionalities are being used in the formulation of asphalt mixtures in several European countries. Resistance to moisture damage is exemplified in the French and Belgian contexts, with respectively a case study showing the use of Hydrated Lime modified Asphalt Concrete (AC) in the severe conditions of continental road mountains (tough winter, curves) and in the case of Stone Mastic Asphalt (SMA) mixtures. Aging resistance is highlighted in the framework of German and Polish case studies on AC and SMA mixtures respectively. Finally, the effect of binder stiffening is explained in the context of Austrian (AC) and Italian (Porous Asphalt, SMA) examples. These various case studies all concur to the fact that the use of an active filler such as hydrated lime mak es it possible for the formulator to have an efficient way to adjust asphalt mixtures properties, besides the more usual choices of aggregate and binder.