Introduction. Asphalt concrete is the most common material for arranging road pavement layers. The significant advantages of asphalt concrete include high performance characteristics, relatively high technical indicators, suitability for regeneration, etc. At the same time, asphalt concrete also has disadvantages, one of which is the significant dependence of strength and deformation characteristics on ambient temperature. Problem statement. Currently, there are no clear criteria for the selection of bitumen in Ukraine that would take into account the conditions of asphalt concrete in the design of pavement structure, but the first steps are already being taken in this direction. The purpose of this work was to practically determine the required properties of bitumen in accordance with the previously proposed algorithms. Objective. Practical determination of the required properties of bitumen in accordance with the previously proposed algorithms. Materials and methods. Analysis of the algorithm for determining the required properties of bitumen, climatic conditions of asphalt concrete and calculation of the required bitumen grade when designing a pavement structure. Results. Suggestions for improving the algorithm for selecting bitumen when designing a pavement structure are provided. An analysis of the climatic conditions of asphalt concrete operation and the calculation of the required bitumen grade according to performance indicators when designing a pavement structure for a conditional road section were performed. A system for selecting bitumen by penetration classification based on established performance indicators is proposed. Conclusions. The proposed algorithm for determining the required bitumen grade when designing a pavement structure can be used to determine the bitumen grade both by performance and penetration classification.
Introduction. Asphalt concrete is the most common material for paving layers of roads. Significant advantages of asphalt concrete include high operational characteristics, relatively high technical values, suitability for regeneration and more. At the same time, asphalt concrete has its drawbacks, one of which is the significant dependence of strength and deformation characteristics fronm the ambient temperature. The essential role in the temperature properties of asphalt concrete is played by bitumen, the quality of which is currently evaluated by standard indicators in accordance with the penetration system. The properties of bitumen can be more accurately and objectively evaluated by rheological indicators (viscosity and cohesion) or by operational ones, which are determined depending on the climatic conditions of asphalt concrete layers. Therefore, there is a need to analyze the climatic conditions of asphalt concrete in the pavement structure. Problem statement. Today in Ukraine a penetration system uses for evaluation of bitumen properties that determines the type of bitumen and the corresponding characteristics. About 30 years ago, the United States developed a system for evaluation of bitumen operational characteristics, which combines climatic conditions and transport loadings. This approach allows to choose bitumen for assigned designing combination of high and low temperatures. Evaluation of the appropriate climatic conditions of asphalt concrete in Ukraine will allow to develop zoning on the basis of which it is possible to make the optimal choice of bitumen, which would increase the durability of asphalt concrete and pavement structure in general. Purpose. Creation of bitumen selection system during designing of pavement structure, considering the ambient temperature, transport loadings, traffic intensity, level of reliability and location of asphalt concrete in the pavement structure. Materials and methods. Collection of climatic data regarding ambient temperature according to the data of meteorological stations located in regional centers of Ukraine for the period from 2005 till 2020 and determination of the needed operational properties of bitumen. Results. The zoning of the territory of Ukraine according to the climatic conditions of asphalt concrete considering the ambient temperature, transport loadings, traffic intensity, level of reliability and location of asphalt concrete in the pavement structure is developed. Conclusions. Development and introduction of zoning of the territory of Ukraine according to the operational conditions of asphalt concrete and bitumen selection system according to operational indicators will prevent the formation of destruction in the form of plastic deformations, cracks and low-temperature cracks and thus will increase the durability of asphalt concrete. Keywords: asphalt concrete, bitumen, binding layer, operational properties, pavement structure, pavement layer, upper layer of foundation.
Introduction. Currently, in Ukraine, there are restrictions on the traffic of vehicles with an actual weight of more than 24 tons and an axle loading of 7 tons during the day at an air temperature above 28 °C, except for vehicles carrying dangerous, perishable goods, live animals and poultry, and as well as transportation related to the prevention or liquidation of the consequences of emergency situations. An air temperature of 28 °C is considered to be the temperature at which the road pavement structure under the influence of dynamic loadings can sharply lose its load-bearing capacity, which is one of the conditions under which a threat to traffic safety is created or roads can be damaged and destroyed. Problem statement. The analysis of the regulatory documentation showed that during designing of pavement structure, the climatic conditions of asphalt concrete performance should be taken into account and pavement must withstand the accumulation of plastic strains in summer, which requires measures to ensure its rutting resistance. At the same time, the algorithm for ensuring rut stability does not exist yet. It is quite likely that this issue can be resolved by performing appropriate research work and implementing harmonized European standards, respectively, by amending the building codes, etc. However, the question arises whether we do not perform the requirements of the regulatory documentation and design the pavement structure without considering the climatic conditions and ensuring the rut resistance of asphalt pavement, or still comply with these requirements, which should be clarified. Objective. Development of criteria for analyzing the performance conditions of asphalt concrete in the pavement structure and ensuring its rutting resistance during operation. Materials and methods. Prerequisites for the establishment of restrictions on the movement of freight vehicles at air temperatures above 28 ° C, analysis of operating conditions of asphalt concrete in the construction of pavement. Results. According to the results of the work, the influence of temperature, bitumen properties and loading time on the change of asphalt concrete properties has been established. Criteria for the analysis of climatic conditions of asphalt concrete have been developed and criteria for taking into account operating conditions have been established. Approximate bitumen grades for ensuring the asphalt concrete rutting resistance have been established on the basis of establishing the relationship between the standard properties of bitumen and operating properties. Conclusions. For evaluation of possible rut formation resistance of asphalt concrete, it is needed to perform an analysis by the bitumen grade in its composition, the total number of passes of vehicles with estimated loadings during the pavement operational term, the category of road, the type of asphalt concrete, the speed of traffic, as well as the year of pavement arrangement. In order to ensure the rut resistance of asphalt concrete, it is advisable to use the established criteria in the future during the pavement design.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.