Wettability of Asphalt Concrete with Natural and Recycled Aggregates from Sanitary Ceramics

Materials (Basel). 2020 Aug 28;13(17):3799. doi: 10.3390/ma13173799.

Abstract

In line with the current trend of seeking alternative methods for modification of the existing building composites, such as mineral-asphalt mixtures (MAMs), the materials from concrete and ceramics recycling are being used in increasingly wider applications. When added to MAMs as an aggregate, ceramic building material, which has different properties than the raw material (clay), may significantly influence the aggregate properties, including the wettability, porosity, asphalt adhesion, and consequently the mixture durability. The material's microstructure was found using SEM. The wetting properties of mineral-asphalt mixtures were determined by measuring the contact angles (CA) of their surfaces, using water as the measuring liquid. The total surface free energy (SFE) values were determined using the Neumann method. When analyzing the research results, it can be noticed that the chemical composition of the ceramic aggregate has a significant influence on the adhesion of asphalt to its surface due to the chemical affinity. Waste ceramic aggregate, despite its acidic pH value being connected with its elevated silica content, exhibits good adhesive properties.

Keywords: aggregate from sanitary ceramic wastes; mineral–asphalt mixtures; porosity; surface free energy; wettability.