Rheological and performance characterisation of cold bituminous mastics made with different bitumen emulsions and mineral fillers

In recent years, the evolution in the field of bituminous binders has led to the affirmation of modified emulsions for cold recycled asphalt mixtures (CRAM). However, the behaviour of CRAM, as a function of the emulsion type and the modification process, is still not understood. The paper deals with the analysis of mastics made with three different types of bitumen emulsion (unmodified, pre-blended SBS-modified, and post-blended latex-modified) and three different types of filler (limestone filler, lime-based filler, and plant-collected filler). The laboratory investigation included the measurement of the delta ring and ball, the linear viscoelastic characterisation, and the evaluation of the resistance to permanent deformations and fatigue damage. The results showed how, in defining the properties of a cold bituminous mastic, it is not only the presence or absence of polymers that is important but also the modification method, as well as the type of filler.