INVESTIGATION OF SURFACE PROPERTIES OF MODIFIED BITUMEN COMPOSITIONS

Abstract

Introduction. One of the main reasons for premature destruction of road surfaces is the poor quality of road bitumen. An effective way to improve the quality of a bitumen binder is to modify it with polymer or surface-active additives. The goal is to determine the effect of the concentration of modifiers on surface tension in binary "bitumen-surfactant", "bitumen-polymer" and triple "bitumen-surfactant-polymer" systems. The methodology of the work included measuring the surface tension of modified bitumen systems depending on the quantitative content of additives in bitumen. Results and discussion: As follows from the analysis of the data obtained, in bitumen systems with a limited concentration of polymer AG-4I (C≤1 g/dm³), the effect of reducing surface energy at the interface with air is achieved by concentrating surfactants in the surface layer, which are part of the structure of the bitumen itself. The extreme nature of the change in surface tension was also recorded in AC-2 bitumen compositions. Conclusion: In the "bitumen-AG-4I-AS-2" triple systems, the change in the specific surface energy at the "liquid-gas" interface is not an additive value, taking into account the separate contribution of AG-4I and AS-2. The concentration threshold of additives to achieve a minimum surface tension varies in comparison with binary compositions. With the combined administration of AG-4I (C=1g/dm³) and AC-2 (C=1g/dm³), the surface tension decreased by 9.30 mN/m compared with unmodified bitumen.