69439 2658-5553 22 2 22 2022 1-50

RAR RUS 2201-2201 0000-0002-0787-4259 Volga State University of Technology Veyukov Evgenij Valerianovich VeukovEV@volgatech.net

Lenin Sq., 3, Yoshkar-Ola, Russia, 424000

0000-0003-0406-7360 Volga State University of Technology Salihov Muhammet Gabdulhaevich SalihovMG@volgatech.net

Lenin Sq., 3, Yoshkar-Ola, Russia, 424000

0000-0002-2472-9483 Volga State University of Technology Gorshkov Kirill Sergeevich GorshkovKS@volgatech.net

Lenin Sq., 3, Yoshkar-Ola, Russia, 424000

0000-0002-8721-0144 Volga State University of Technology Ponedelko Lyudmila Ivanovna PonedelkoLI@volgatech.net

Lenin Sq., 3, Yoshkar-Ola, Russia, 424000

Aging of Sandy Asphalt Mixes with Anti-aging Additives The object of research is sandy asphalt concrete mixtures. Asphalt concrete in the process of preparation and operation irrevocably reduces its mechanical properties, which is called aging. This process depends on the composition, structure, and size of mineral materials, the physical and mechanical properties of the bitumen used, temperature, and other factors. To reduce the intensity of aging of asphalt concrete, a method has been proposed to improve its properties by introducing additives of anti-aging agents. Method. When preparing sandy asphalt concrete mixtures, various additives are introduced into their composition. Subsequently, samples are formed, and a comparative assessment of various physical and mechanical properties is carried out. Carbon black, sulfur, and the stabilizing additive Viatop-66 were used as additives. The estimation of the rate and intensity of aging was established according to the method provided for by the patent of the Russian Federation No. 2654954 (Volga State Technological University, Department of Building Technologies and Highways). Aging was carried out by preliminary keeping the prepared mixtures in an oven at a temperature of 150 °C for 1, 3, 5, and 7 hours. The static modulus of elasticity was estimated by stepwise loading of asphalt concrete samples by fixing the values of total and residual deformations. Results. It was found that the introduction of some of the proposed additives made it possible to reduce the intensity of aging of asphalt concrete. The aging coefficient of the base composition (without additives) for 7 hours at a temperature of 150 °C was 1.40, the composition with carbon black was 2.33, with sulfur it was 1.39, and with a stabilizing additive, it was 2.74. Correlations between the values of the aging coefficient of asphalt concrete and mixtures with various additives were obtained in the CurveExpert software environment. The obtained dependencies allow us to analyze the influence of the applied additives on the processes of aging of asphalt concrete over time and rank them according to the degree of influence on the dynamics of this process. 10.57728/ALF.22.1 69 Limestone Asphalt Asphalt mixtures Durability Elevated temperature Binders Modified bitumen https://alfabuild.spbstu.ru/article/2022.22.1/

RAR RUS 2202-2202 H-9967-2013 16412815600 0000-0002-8588-3871 Moscow Power Engineering Institute Kirsanov Mikhail Nikolaevich mpei2004@yandex.ru

Moscow, Russian Federation

The natural frequency of a truss with double braces The object of study is a statically determinate plane regular truss with parallel belts. The derivation of the formula for the dependence of the first natural oscillation frequency of the truss on the number of panels and the rigidity of one of the support links is given. Method. The forces in the rods are determined in symbolic form by cutting out nodes from the solution of a system of linear equations in the Maple computer mathematics system. The system of equations includes both the forces in the rods and the reactions of the supports. The masses concentrated in the truss nodes have two degrees of freedom. To determine the rigidity of the structure, the Maxwell-Mohr formula is used. Based on a series of separate analytical solutions for trusses with a different number of panels, a general solution is obtained by induction, which is valid for any number of panels. Analytical transformations and numerical solution of the spectrum problem are carried out in the Maple symbolic mathematics system. Results. Comparison of the found analytical results with the numerical solution of the problem of the spectrum of natural oscillations of a system with a finite number of degrees of freedom shows its high accuracy, which grows with an increase in the number of panels. 10.57728/ALF.22.2 69 Truss Analytical Solution Natural frequency Maple Induction Dunkerley method Mohr integral https://alfabuild.spbstu.ru/article/2022.22.2/

RAR RUS 2203-2203 0000-0002-0683-2786 Peter the Great St. Petersburg Polytechnic University Grebenyuk Egor Alexandrovich inj5@yandex.ru

St. Petersburg, Russian Federation

57216911176 0000-0003-2716-979X Peter the Great St. Petersburg Polytechnic University Novik Anatoly Nikolaevich novik.anatoliy@inbox.ru

St. Petersburg, Russian Federation

Open elevation WorldDEM in comparison with aerial laser scanning The object of research is open digital elevation models - Airbus WorldDEM with a spatial accuracy of 24 meters taking into account the anthropogenic environment. There was analyzed their’s compliance with the real surface (a result of aerial geodetic surveying) for different coverings in the territory of Nizhny Novgorod agglomeration, Russia. Used method of researching – create compare surfaces between two data sources (by survey and open elevation – WorldDEM) with subsequent sorting count of points by their's elevation’s differences. In each area, we had been finding places with the biggest elevation collisions and determined real objects, which were the reason for detected collisions. As a result, we made a conclusion about the possibility of using WorldDEM for villages and water surfaces where elevation’s collision is less than the data’s accuracy; there are many deviations in parks and forests with dense natural; in high-rise urban's environments there is permanent vertical’s offset in results surfaces, that may be a reason of no-detail (24m) of used open elevation data. 10.57728/ALF.22.3 69 Surfaces SRTM DEM WorldDEM Open Elevation Digital Models CIM BIM https://alfabuild.spbstu.ru/article/2022.22.3/ 2203_1.pdf

RAR RUS 2204-2204 0000-0002-1418-9858 Yaroslavl State Technical University Balushkin Alexander Leonidovich albalush@mail.ru

Russian Federation,Yaroslavl, Moskovsky av. 88

The role of mutual shear deformations in ensuring the safety of prestressed reinforced concrete elements The object of study is prestressed reinforced concrete elements, with reinforcement tension on stops in the manufacturing and maintenance stages. It is noted that of all the significant parameters of bond - the stiffness of the contact of concrete with a prestressed reinforcing element can most reliably assess and ensure safe working conditions for the reinforced concrete element as a whole. Method. The determination of mutual shifts of reinforcement and concrete is carried out using the theory of built-up bars, adapted for prestressed reinforced concrete elements. A method for estimating mutual shear strains for elements with single and double prestressed reinforcement is presented. Recommendations are given for calculating the parameters of bond stiffness. Results. For a multi-hollow slab, the nature of the distribution of mutual shear deformations along the length of the structure for different stages of the life cycle is shown. It is proposed, when checking the strength of reinforced concrete elements with prestressed reinforcement, according to the deformation model, to additionally introduce a check of mutual shear deformations at the contact of concrete and reinforcement. 10.57728/ALF.22.4 69 Prestressed reinforced concrete elements Life cycle stages Bond (adhesion) of reinforcement to concrete Mutual shear of reinforcement and concrete Built-up bar https://alfabuild.spbstu.ru/article/2022.22.4/ 2204-1.pdf

REV RUS 2205-2205 0000-0001-6383-6639 Peter the Great St.Petersburg Polytechnic University, Russian Federation Nazinyan Levon Gaykovich nazinyan.lg@edu.spbstu.ru

Saint-Petersburg, Russia

ABG-7557-2020 57218103892 0000-0001-5244-8024 Peter the Great St.Petersburg Polytechnic University Shevchenko Sergey Mikhailovich shef10b@yandex.ru

Saint-Petersburg, Russia

Use of processed plastic products in road construction. A review The object of research is the use of recycled plastic in road construction. The incineration of plastic waste in waste recycling plants is harmful to the environment due to the release of toxic gases, so the use of recycled plastic products remains the only environmentally friendly solution. To assess the advantages and disadvantages of modern ways of using recycled plastic waste in road construction, studies carried out in recent years in this direction were analyzed. Methods. For compiling a survey, there were used only modern sources. Results. It was revealed that today the main way of using recycled plastics is to modify the asphalt mixture with them. This method does not require new production technologies and is advantageous from an economic and technical point of view. However, studies show that polymer modification of asphalt mixes is harmful to the environment in the long term due to the abrasion of the plastic and the release of toxic substances. Another way of introducing plastics in road construction has great potential from an environmental point of view - the creation of roads from plastic plates. By using separate wear-resistant layers, these plastic boards are environmentally friendly and fulfill their function. But examples of the use of plastic plates are still too few to analyze their effectiveness because their technology has not yet been finalized. The result of the review is the conclusion that further research should be carried out in the direction of designing plastic roads from polymer plates or blocks. 10.57728/ALF.22.5 69 Plastic roads Plastic waste Polymers Bitumen mixture Aggregate Recycled plastic https://alfabuild.spbstu.ru/article/2022.22.5/ 2205.pdf