An experimental study on viscoelastic behaviour of bituminous mastics

The viscoelastic properties of asphalt mastics are influenced by the type of aggregate that is mixed with the bitumen. The objective of the investigation reported in this paper is to explore the use of an inorganic municipal waste filler (WBA) in bituminous mixtures. These materials are available in large quantities and provided at shipping cost, because of landfill problems. However, their use is still limited due to the intrinsic variability of the electrochemical relationship that occurs between aggregates and bitumen. A comparative study on the viscoelastic performance of bituminous mastics is presented. The bitumen were free of polymer modification. All adhesive mastics were prepared using a single type of filler. The filler-bitumen mass ratio was varied in order to analyse its influence on material response. The filler is homogeneous; particles larger than 0.063 mm were excluded. The programme of laboratory tests evaluated both the rheological and empirical properties, according to the European Standard. The results obtained demonstrate that the slag filler can be used as a replacement for the standard filler. The composition of the structure of the aggregates in bituminous mixtures was noticeably altered. However, the variation of the filler-bitumen mass ratio can determine some advantages on mechanical response, strength and yield level of the mastic.