KazDorNII conducts research to improve the binding properties of road bitumen

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The quality and durability of asphalt roads depend both on the observance of construction technologies and on the materials used to make the pavements. In particular, one of the main reasons for the premature destruction of asphalt concrete pavement is the poor adhesion of bitumen to mineral filler from acidic rocks.

The experience of road operation in Kazakhstan and abroad indicates that, upon contact with mineral material, water easily wets crushed stone grains and peels off a bitumen film from their surface. In this case, the detachment of the binder is always due to insufficient adhesion strength.

In July 2021, at an expanded meeting of the Government, the Head of State focused on ensuring the high quality of roads. In this regard, KazdorNII is implementing a program aimed at studying new technologies for the manufacture of the roadway. Within its framework, tests are carried out to evaluate the adhesion of a bituminous binder with mineral materials at various temperatures, by determining the dielectric constant. Also in the laboratories of the institute, including the Superpave system on BBR, DSR and PAV devices, the influence of various adhesive additives on the aging processes of bitumen is determined.

A comparative analysis of the methods used will make it possible to estimate the adhesion of binders to stone materials in a wide temperature range with the receipt of new data. These data can be used to develop binder compositions with improved adhesive properties and more durable asphalt mixes.

In addition, in the course of research, work was carried out to establish the chemical and structural analysis of mineral materials of various rocks. Regularities will be derived for the influence of the morphology of the stone material used on the degree of their adhesion to the bituminous binder.

Also, based on the data of the chemical component of mineral materials, an assessment of their applicability for certain road technologies is given.

The results of the research work will make it possible to select the optimal components of the asphalt concrete pavement (binder, adhesive additives and stone material) for different climatic conditions and, due to this, increase the service life of road surfaces by 3 years, as well as reduce operating costs when maintaining roads by 15%.