Velocidad de rotura de las emulsiones bituminosas en contacto con áridos

Resumen

Cold-mix paving technology based on bitumen emulsions involves complex phenomena of mainly kinetic character. The key stage of bitumen film formation on aggregates, in order to obtain high-performance dense-graded cold mix asphalt, is the emulsion breaking. The bituminous phase and aqueous phase break their colloidal equilibrium in this step. The speed of this stage is used to classify emulsions manufactured upon different conditions. A suitable parameter to quantify these differences is the breaking time. In this work, an objective and reliable method to measure easily the characteristic time during phase separation is explained. This approach improves the qualitative results of conventional assays designed to this task and requires little amount of materials (emulsion as well as aggregates). Besides, the experimental conditions are closer to real ones with few initial restrictions. Emulsions studied in this work were manufactured with three cationic emulsifiers at several concentrations and three bitumen of different origin.