Effectiveness of the iDOP-PH adhesion promoter in relation to adhesion of the pavement bitumen

Abstract

Asphalt pavement is permanently influenced by various environmental conditions and traffic load. Because of this after a certain period numerous defects may appear on the surface of the road pavement. These defects include peeling, chipping, pots, cracks etc. The low water proof resistance of the asphalt concrete (conditioned by low adhesion of the bitumen to aggregate surface) is considered to be one of the reasons for appearance of these defects. Adhesion promoters’ use is the most common method to increase adhesion activity of pavement bitumen. Goal. The objective of the current research work is the evaluation of influence of the domestic adhesion promoter iDOP on the conventional and adhesion properties of bitumen. Methodology. To achieve this goal, the following was done: the effect of the adhesive promoter iDOP on the standard quality indicators of bitumen was determined according the requirements of the current standards DSTY 4044 and SOU 45.2-00018112-067; the effect of the adhesive promoter on the adhesion of bitumen to the glass surface (according to the DSTU B.V.2.7-81 method) and to the surface of aggregates with different mineralogy was evaluated by the rotating bottle method according to DSTU EN 12697-11; the thermal stability of the iDOP-PH promoter was tested by simulating the technological ageing of bitumen according to the method given in GOST 18180 and the RTFOT method. Results. Grounding on the experimental data obtained, it was found that the adhesive promoter iDOP-PH does not affect the standard indicators of the quality of bitumen (penetration, softening and breaking point temperatures, ductility). During hardening with the RTFOT method, a slight inhibitory effect of the promoter is observed, which appears as an increase in the values of residual penetration and ductility compared to bitumen without promoter. The iDOP-PH promoter increases the adhesive capacity of bitumen, which is confirmed by the adhesion data determined by the improved method given in GOST B.V.2.7-81 and the rolling bottle method. Originality. It is shown that the iDOP-PH promoter has a relevantly low thermal stability. With this the main factor affecting the decrease in thermal stability is the long time exposing of the binder at high temperature by GOST B.V.2.7-81 method. Practical value. It is shown that the promoter concentrations recommended by the supplier are insufficient, and to ensure the required values of the adhesion (standardized in СОУ 45.2-00018112-067) it is advisable to increase the concentration of the iDOP-PH promoter in bitumen to 0.3 - 0.6%.