ESTABLISHMENT OF TECHNICAL REQUIREMENTS REGARDING DRAINING ASPHALT CONCRETE

Abstract

Introduction. It has been established that porous draining asphalt concrete (DAC) is an open-frame asphalt concrete that is specially designed with a high content of air voids, which are designed to remove water from the surface of the road surface. Pavement surfaces that include draining asphalts, permeable wear courses, and porous asphalt pavements are gaining more and more acceptance in the road industry worldwide. Drainable asphalt can be susceptible to freeze-thaw damage in cold climates and will require winter maintenance practices. The service life of such coatings varies greatly depending on climatic conditions, intensity of traffic and loads, design and construction methods. Drainage asphalt pavements were created to increase road safety, but in addition to high traction characteristics, they have high porosity, which provides water permeability, which reduces the amount of surface water and thus reduces the formation of splashes in rainy weather. This leads to a reduction in the risk of aquaplaning and an increase in road visibility, and ultimately to an increase in road safety.. Problem statement. The issue of timely removal of surface water from the road surface is mandatory and is solved by providing the road surface with a transverse slope. As practice shows, this does not sufficiently protect the road surface from the negative effects of water. High operational safety, improvement of the operational characteristics of the road surface is achieved due to the removal of the accumulation of water stains from its surface, which reduce the adhesion of the wheels to the road surface. These qualities can be improved by introducing draining asphalt concrete. However, the service life of draining asphalt concrete varies greatly depending on climatic conditions, traffic intensity and loads, design concepts and construction methods. In order to further improve the current state-of-the-art instructions for the production and application of DAC to solve regional, road and climate problems, a comprehensive analysis of the currently available applications of DAC mixtures for the construction and maintenance of road surfaces is necessary. Therefore, on the basis of this, today in Ukraine it is expedient to introduce normative documents that would regulate the design, manufacture, technical requirements and performance of works according to this technology, which would allow for practical use, optimization and development of the road industry of Ukraine in this direction. Purpose. Production of asphalt concrete mixtures and arrangement of road surface from draining asphalt concrete. Assessment of the regulatory framework of the world and establishment of recommendations and technical requirements for the production and installation of draining asphalt concrete. Materials and methods. Experimental and experimental-analytical. Results. An analysis of the existing experience of using draining asphalt concrete, conditions of its use, was carried out. Theoretical studies of the process of forming asphalt concrete with a structure of interconnected open pores. Experimental studies on the selection of grain composition and bitumen content in draining asphalt concrete have been conducted. Recommendations for the production of draining asphalt concrete mixtures and the arrangement of a covering from them have been developed. Conclusions. An important role in the operational reliability and durability of draining asphalt concrete is played by the properties of the components, as well as the ratio between mineral materials and bituminous binder. In European countries, the greatest attention is paid to the narrow grain composition of mixtures, especially the requirements for large aggregates and bituminous binders. For the production of drainable asphalt concrete, crushed stone of narrow fractions is used, since it has a special granulometric composition, unlike typical dense and crushed-mastic asphalt concrete, it has sufficiently large porosity and requires extremely high attention and strict requirements for crushed stone materials. Therefore, an important step for the implementation of a promising construction technology would be the development of recommendations for draining asphalt concrete in Ukraine, which will include technical requirements, recommendations for design and application, acceptance rules and control methods.