Огляд підходів до прискореного моделювання довгострокового старіння бітумних в’яжучих

Abstract. Problem. One of the reasons for the change in the physical and mechanical quality indicators of asphalt pavement during its operation is the aging of bitumen binder, which is caused by various technological, climatic, and operational factors. The goal of the work is to analyze the existing accelerated methods of long-term aging of bituminous binders. To achieve this goal, the analysis of foreign literature sources devoted to the issue of long-term aging of road bitumen binders was carried out. Methodology. At present, the only generally accepted industrial method for the long-term aging of bituminous binders, which has been widely used in laboratories around the world, is the PAV method. The advantage of this method is the availability of equipment manufactured by different manufacturers, as well as the possibility of aging at different temperatures, which simulates the long-term aging of binders in asphalt pavements operated in different climatic conditions. Significant disadvantages of the method are the relative duration of the test, which, together with preparatory measures, extends for 22-24 hours, and the significant cost of the equipment set. Results. Proceeding from the fact that the starting material for aging by the PAV method is bitumen binders that have been previously subjected to short-term aging by the RTFOT method, scientists from around the world have carried out research aimed at selecting the parameters of aging by the RTFOT method, which would contribute to obtaining a binder that would correspond in its properties to the properties of bitumen aged by the PAV method. Based on the data from the literature, it was found that in the case of using the standard aging temperature, 255-340 min is an equivalent time of aging by the RTFOT method, which leads to the same change in the quality of road bitumen as after aging by the PAV method for 20 h. Recently, an accelerated method for assessing the long-term aging of road bitumen has been spreading in the European Union, according to which, to achieve the same level of bitumen aging observed after aging by the PAV method, it is possible to triple the aging time by the RTFOT method. Currently, this method is standardized in Austria and the Czech Republic and applies mainly to road bitumen grades 50/70 and 70/100. Given the significant reduction in aging time, this method is relevant for predicting the durability of asphalt pavements at the design stage of the asphalt mixture composition. Practical value. Given that there is currently an urgent need in the road industry to assess the susceptibility of road bitumen to short-term and, especially, long-term aging, and taking into account that it is unlikely that domestic road laboratories will be equipped with a set of equipment used in the PAV method in the near future, testing and standardization of accelerated long-term aging methods in Ukraine is relevant.