Wettability and Surface Free Energy of Mineral-Asphalt Mixtures with Dolomite and Recycled Aggregate

The study on the wetting properties and surface free energy (SFE) of mineral-asphalt mixtures was presented in the paper. The composition of the two mineral-asphalt mixtures was prepared: the mixtures with dolomite and the mixtures with dolomite and recycled ceramic aggregate. The use of different aggregates results in diversification of the wetting properties in porous bituminous mixtures. The microstructure was shown based on the SEM study. The wetting properties of mineral-asphalt mixtures were determined by measuring the contact angle of their surface using water as measuring liquid. Measurements were carried out immediately after the time of application of the drops. The total surface free energy (SFE) was determined using the Neumann method. While analysing the examination results it can be noticed that the values of contact angles depends on the type of aggregate used in mixtures and the smoothness of mineral-asphalt mixtures surface. The highest contact angle was noticed for the bituminous mixture with dolomite aggregate on flat surface. The smallest contact angle with water was obtained for the mineral-asphalt mixture with dolomite and recycled ceramic aggregate on rough surface. This is due to the physical characteristics of this aggregate. Ceramic aggregate is characterized by the high absorbability. This indicates an increased wettability and adhesion properties.