Development and validation of a laboratory aging method for the accelerated simulation of reclaimed asphalt

Abstract

The paper presented first results elaborated during the European Research Project Re-road which aims at the development of techniques for increasing the recycling rates of reclaimed asphalt. During service life surface asphalt courses are subjected to aging due to oxidation effects which causes the hardening of the binder and thereby a change in the chemical, physical and mechanical properties of the material. Surface courses often contain highly modified binders as well as special additives for improving the performance characteristics. As these layers inhibit the shortest service lives compared to other road construction layers every year high amounts of reclaimed surface asphalt are available for recycling. The question is raised how the reclaimed asphalt consisting of high quality and costly material components can be recycled for optimal added value. To analyze the asphalt mix service life performance and its recyclability during mix design a laboratory method was developed to simulate the real in-situ aging. First the effects of site aging on the binder and asphalt characteristics were presented. Three laboratory aging methods were discussed which aimed the accelerated aging which meets similar property changes as site aging. At last the effects of two different laboratory aging methods on the same SMA mixture were compared.

Effects Of Laboratory Short-Term Ageing On Bitumen Properties

“…It is also quite challenging to investigate due to the various variables such as precipitation, temperature, sunlight (UV), wind and others (Mouillet et al, 2009;Garrick, 1994). Therefore, many researchers have diverted their attention and proposed substantial evaluation tests and parameters to assess the ageing behaviour and ageing resistance of bitumen (Akbarnejad, Houben, & Molenaar, 2014;Mollenhauer, Pierard, Tusar, Mouillet, & Gabet, 2010;Li, Zhang, & Wang, 2007;Zhang, Liang, & Li, 2005;Airey, 2003;Shenoy, 2002). Lu, and Isacsson (2002) observed that bitumen ageing may be affected concurrently by numerous factors, such as bitumen content and properties, aggregate nature and particle size distribution, air voids, factors related to production, and external conditions such as time and temperature.…”