Licentiatavhandling Stockholm : Kungliga tekniska högskolan. Institutionen för transportvetenskap, 2013

Sufficient coating, easy paving and good compaction are desirable parameters, which are approachable with the optimum viscosity of the mastics. Viscosity of mastics at the higher temperature is affected by several parameters, such as filler concentration, shape, size, size distribution, bitumen type and filler-bitumen interaction. Understanding the effect of these parameters on the viscosity of mastics can lead to the better design of mastic to have optimum workability of asphalt mixture and eventually desirable performance. In many studies, models have been developed for calculating the viscosity for different types of suspensions at various particle-to-fluid ratios. Unfortunately, none of them are applicable to asphalt mastics, since this material has a much wider range of mineral filler concentration from dilute to very concentrate. To give an overview of the existing viscosity models and to evaluate their range of applicability to asphalt mastics, an extensive literature review was performed. A new empirical framework was developed that removes some of the stipulated limitations of the existing theories. Then, a description is given of the measurements of mastic viscosity for different types of mastics in which the bitumen source is kept as a constant, but with varying fillers as well as concentrations. The environmentally susceptibility was hereby also investigated by conditioning the samples to ageing and moisture conditioning. Results showed, the developed test protocol was able to clearly identity filler properties on the mastic viscosity. Furthermore, a critical filler concentration was identified beyond which the viscosity behaviour becomes non-linear. It is also showed that the moisture and aging have significant effect on the viscosity of mastics.