Effect of the nature and filler content on cohesion, adhesiveness and rheological behavior of the bituminous mastics

Bituminous mastic behavior depends on the filler/bitumen volumetric ratio and the nature of the filler employed. This work gathers the study made by the Diputacion Foral de Gipuzkoa for the characterization of different types of fillers and, especially, fillers resulting from the manufacture of bituminous mixtures, bag-house fines. The influence of these fillers in the rheological behavior of different types of bitumen (modified and non-modified) was analyzed by means of the DSR equipment (Cepsa-Proas). In addition, the effect of mastics on the cohesion and adhesiveness with acid and basic aggregate has also been studied. The rheological characterization of the analyzed mastics shows hardly any difference between them. An increase in the modulus, G*, is observed with respect to the original bitumen (without filler), whereas the phase angle remains almost invariant. Moreover, it is impossible to determine the optimal filler content. In contrast, characterization by the UCL method not only reveals differences in the response of mastics but also allows the point from which filler content results in excessive mastic fragilization to be clearly established. It is also possible to determine which mastic provides the mixture with greater resistance to the stripping action of water. For the covering abstract see ITRD E157233