INTERPHASE PROCESSES IN MODIFIED BITUMEN SYSTEMS

Abstract

Introduction. The unsatisfactory quality of asphalt concrete road surfaces in most cases is due to poor adhesion between the bitumen binder and the surface of the mineral filler. The aim is to establish the influence of modifiers of various natures on the development of interphase processes in modified bitumen compositions. The methodology of the work included measuring the contact angle of the crushed stone surface with modified bitumen systems depending on the quantitative content of additives in bitumen and evaluating the adhesive effectiveness of modifiers. Results and discussion. As follows from the analysis of the data obtained, the introduction of AC-2 into bitumen favours the wetting of the crushed stone surface, which, as a result, is confirmed by a decrease in the contact angle. The values θ of solutions of bitumen with AC-2 decreased by 6.73° as its concentration increased from 0 to 3.0 g/dm³. The results of measurements of the wetting edge angle in the binary bitumen-AG-4I system indicate that the polymer additive also stimulates the process of wetting crushed stone with bitumen, but less intensively. The maximum decrease in θ was 3.26° at C_AG-4I =1.5 g/dm³. Conclusion. With an increased content of AC-2 (C_AC-2=1.0 g/dm³), cohesion and adhesion increase and reach their maximum at C_AC-2=2.5 g/dm³: W_K=89.68 mN/m, W_A=13.90 mN/m, A=68.55%. In the presence of a sealing liquid in bitumen, the adhesive-cohesive effect has a maximum at the same concentration point (C_AG-4I =2.5 g/dm³) and is: W_K=90.20 mN/m, W_A=10.79 mN/m, A=92.25%.