Introduction. The paper considers the throttle regulation providing flow continuity of working fluid for the purpose of cavitations’ prevention. The throttle regulation in a hydraulic actuator of the load-lifting mechanism under the influence of static and dynamic loads taking into account elastic deformations of a hydraulic system while the boom lowering with a load is an important process. The boom lowering is carried out by the working fluid supply in a stocked cavity of a cylinder by the pump of constant productivity; draining of working fluid is made through the one-sided action throttle.

Materials and methods. The consumption of working fluid from a piston cavity provided the constant movement speed of the piston without external loading change. Regulation of speed while the boom lowering was carried out by change of effective section of the throttle opening in pressure. The authors used dynamics of hydraulic actuators, mechanisms and machines, resistance of materials and differential equations.

Results. The presented technique allowed determining the value of the working fluid pressure and its change in the throttle. Moreover, this technique determined the area of the throttle providing flow continuity while the boom lowering, depending on design features of the kinematic scheme of the loadlifting mechanism, on the mass of the lowered load and technology equipment, on the angular arrow acceleration and on elastic modulus of hydraulic system elements.

Introduction. The paper researches the sphere of paving with a roller. The authors describe the current situation in the asphalt concrete’s application as a road surface. Moreover, the authors conduct the excursion into the history of material. The paper presents the preconditions that justify the need for creating recommendations, schemes and methods for experimental study of the working body and material under laboratory conditions of various kinds. The aim of the study is to create the stand concept and methods for experimental research of the roller’s working body in the laboratory.

Materials and methods. The paper described a laboratory stand for experiments in the sphere of roller’s working equipment. The authors demonstrated the construction made of a base, a stiffener box, guides and a movable part with a frame and equipment, suspended above the compacted material’s container.

Results. As a result, the authors presented the detailed methodology for conducting experiments and recommendations for its transformation in the considered sphere. The paper showed all the necessary data for the design, construction of the test bench and experiments with the roller’s working equipment. 

Discussion and conclusions. Researchers, especially beginners, receive an additional tool for study of dependencies and phenomena that occur during compaction of material by the roller. Therefore, the authors develops the scheme for the research of the roller’s working body in small area conditions and in extensive laboratories.

Introduction. Nowadays robotics is one of the most important directions of fundamental, technical, scientific and applied research. The main robotics’ challenges are to develop schemes for obtaining information about environment and the creation of artificial intelligence effective systems of the complex dynamic objects’ control in uncertainty conditions. Recently, robotics is going through the stage of rapid development, more and more covering the civilian and military spheres of human activity. The number of developed and implemented mobile unmanned robotic complexes of military and dual-use exceeds the number of robotic complexes in progress. The purpose of the research is to review the most promising samples of mobile unmanned robotic equipment used in various fields of human activity.

Results. The paper reviewed the modern developments of mobile unmanned robotic complexes applied in the agricultural complex, industrial and civil construction, and in cargo transportation. The authors analyzed promising samples of Russian and foreign unmanned robotic technology. Moreover, the authors presented factors that increasingly depended on key spheres of human activities in the development and implementation of mobile robotic systems. Therefore, the paper demonstrated the list of major programs and concepts for the development of the Russian Federation in robotic sphere.

Discussion and conclusions. As a result, the authors identify the basic elements of automated control systems, of navigation and autopilot system basing on mobile unmanned robotic complexes. The paper also reveals the concept of the foveal vision, which allows quickly and accurately detect pavement roughness and obstacles on the vehicle’s way.

Introduction. The paper describes methods of using the additional left-turn phase of regulation. The authors view the main foreign and domestic methods used in the specialization of the left turn in a separate phase of regulation. To propose a new approach to the specialization of the left-turn direction in a separate phase of regulation the authors investigate one of the most loaded intersections in Voronezh and determine the main characteristics of the traffic flow. Therefore, the authors suggest new parameters in choosing of the necessary method of traffic organization at controlled intersections.

Methods and materials. The paper analyses the main methods, which were conditionally related to two approaches: the accident rate of the site and the characteristics of the traffic flow (speed and intensity of the left-turn flow). The authors explained that the new approach, which took into account such parameters as speed, vehicle delays and queue length, allowed effectively controlling the intersection due to the optimal choice of the necessary traffic organization method and due to the result of changes in the parameters by combining the intensity of the left-turn flow and forward flow.

Results. The authors developed the approach to the additional left-turn section introduction at the controlled intersection based on a comparison of the left-turn intensity and forward flow and on the analysis of changes in the main characteristics of the traffic flow (speed, vehicle delays and queue length).

Discussion and conclusions. The authors concluded that it is necessary to use the proposed approach at the stage of modeling, design and reorganization of the regulated area on the basis of changes in the main characteristics of the traffic flow.

Introduction. The effective operation of cars largely depends on the state of the engines, their downtime in maintenance and repair. Since the maintenance of modern engines is often reduced to the replacement of engine oil, the increase in the duration of its work significantly reduces maintenance costs and downtime in maintenance. Long maintenance-free operation of the internal combustion engines of automotive vehicles is directly related to the state of the engine oil used in this power unit. The aim of the paper is to show the features of the equipment operation with significant intervals of the engine oils’ replacement in order to increase the efficiency of its usage. The paper presents data on the features of the equipment operation when using high-quality motor oils with extended replacement intervals.

Materials and methods. The authors conducted performance tests on the basis of MercedesBenzAxor, MercedesBenzActros cars. The manufacturer provided an estimate of the performance of engine oils. The main performance characteristics of motor oils were assessed using standard methods: kinematic viscosity was measured using a Stabinger viscosimeter, the base number was determined by an automatic AT-500 titrator, the content of wear products was obtained using an ASP-coupled emission spectrophotometer.

Results. As a result, the authors presented data on the dependence of the changes in the main indicators of engine oil performance while the operating time and also substantiated the requirements for the volumes of fresh engine oil to compensate losses.

Discussion and conclusions. The intermediate control allows detecting faults in the internal car engines, as well as providing the most accurate prediction of the resource of the lubricant under consideration. Therefore, the increasing of the engine oil change interval allows getting a significant economic effect.

Materials and methods. The authors performed the analysis of the models for calculating residual deformations accumulated by granular materials and under the influence of repeated loads. The research showed the hereditary nature of the strain granular materials’ accumulation. Therefore, the authors used integral calculus for analytical solution of the residual deformation’s dependence on the number of repeated loads and on the magnitude of the main stresses. Moreover, the authors obtained the solution in the form of logarithmic and power functions, which associated the accumulated deformation with the deformation arising from the first load application. In determining the deformation from the first load application, the authors took into account the model of the theory of plasticity, in which the elastoplastic deformation was determined by the sum of two components elastic and plastic, as well as rheological models considering the deformation as the sum of three or four components. Generalizing the model for various materials, the authors gave the preference to the model, in which the elastoplastic deformation was determined by four components: instantaneous elastic and residual deformations, elastic (elastic-viscous) deformation and a viscoplastic component. Therefore, the residual strain from the first load application was represented by the sum of the two components, instantaneous irreversible and viscoplastic. The viscoplastic component of the deformation was a result of stress relaxation in a relatively short period of time equal to the duration of the load impact. Such research allowed taking into account the effect of speed on the duration of the load and the magnitude of the viscoplastic component of the residual deformation. The authors emphasized that taking into account the viscous-plastic component of residual deformation was most appropriate when calculating residual deformations of soils and materials treated with an organic binder. Granular materials were less sensitive to viscoplastic deformation under a single load application, but, when the voltage exceeded the elastic limit, and the more plastic adaptability of crushed stone, gravel, etc. viscoplastic deformation made a significant contribution to the accumulated residual deformation.

Results. As a result, the authors carried out the analysis of experimental data on the triaxial compression of various granular materials and determined the parameters obtained for the power and logarithmic functions. The authors studied such materials as granite, gneissic, granodiorite and diorite crushed stone, sand, gravel and crushed stone, gravel mixtures with a mineral part from various rocks and fortified sands.

Discussion and conclusions. The paper demonstrates the possibility of using the solutions for calculation of the surface displacement of the pavement layers of granular materials. The authors formulate the tasks for further research.

Introduction. The causes of premature destruction of asphalt concrete coatings are aging and low quality of bitumen. The paper describes the methods for improving the bitumen properties. The authors present the review of the bitumen modification by carbon black usage. The usage of carbon black leads to structural changes in the bitumen. Therefore, the authors select carbon black additives as a promising modifiers.

Materials and methods. The paper showed the characteristics of carbon modifiers and the properties of the initial bitumen.

Results. The authors experimentally determined the main parameters of the modified bitumen and compared the effect of three carbon black additives on the bitumen properties. The usage of activated carbon black significantly reduced the penetration of bitumen than non-activated carbon black, however, the indicators of aging were declined.

Discussion and conclusions. As a result, the solid additive’s usage increases the bitumen viscosity with other standard characteristics’ preservation, and thus improves the bitumen thermal stability. Therefore, the usage of activated carbon black in dry forms does not affect significantly on the bitumen properties in comparison with varietal N 375 grade-carbon.

Introduction. The paper discusses the use of different methods of the hardening concrete’s temperature regime, depending on the boundary conditions specified in the design and construction of the object. Such conditions include the temperature regime of concrete holding, the turnover rate of the formwork and the construction time of the facility, as well as other factors. The aim of the research is a compilation of the various methods of investigation of the temperature regime of hardening concrete, aimed at providing the required timing of the formwork and technological equipment turnover to ensuring the consumer properties of the structures. The scientific novelty of the research lies in the updating and testing of methods for regulating the hardening concrete’s heating, ensuring the formation of the required consumer structures’ properties not previously used in transport and civil construction and based on preliminary modeling of thermal processes occurring in the hardening concrete through the calculation software. The authors on the example of several large objects’ construction consider the most common situations associated with the selection of construction technology in difficult natural conditions by taking into account the required consumer properties: concreting of large-mass structures in a limited time in the warm season and low-mass structures in winter concreting. The research is relevant in view of the large-scale construction in our country as well as of the facilities’ reconstruction.

Materials and methods. The authors carried out the research with the use of modern settlementmeasuring and analytical systems taking into account the change in the thermal stress state of hardening concrete as a function of the temperature change of the concrete mix over time. The use of the modern computational and analytical complex in the physical modeling of the thermo physical processes of hardening concrete made it possible to obtain results as accurately as possible and comparable with observational data obtained during the construction process.

Results. The results allowed authors to project the objects’ concreting of erected in various predetermined conditions while observing the required terms of formwork turnover and ensuring the necessary consumer properties.

Discussion and conclusions. The authors propose measures, the implementation of which makes it possible to build complex construction projects in a short time in special climatic conditions. The paper is useful for engineering and technical personnel and for professionals involved in the study of thermal processes of hardening concrete.

Introduction. The processes of structure formation of cement compositions and the development of effective technologies of building materials is an urgent task for building material science. The use of large-scale man-made product of pulp and paper enterprises – osprey as a fibrous filler in organic and mineral compositions is the successful decision of the problem. The paper analyzes the ways of using osprey in the building materials’ production. The aim of the research is to study the osprey influence on the processes of structure formation of cement stone by quantitative x-ray phase analysis.

Materials and methods. The organic and mineral compositions were obtained on the basis of portland cement and osprey. The authors studied the compositions’ phase of osprey, portland cement and the processes of cement stone structure formation in organ and mineral compositions by quantitative x-ray phase analysis.

Results. The authors determined the compositions’ phase of mineral impurities of osprey, cellulose, cement, cement stone, organic and mineral compositions and two compositions containing 25 and 75% by weight.

Discussion and conclusions. The osprey application as a filler in the organic and mineral composition causes inhibition of processes of cement hydration. The presence of osprey in the hardening organic and mineral composition leads to a change in the composition and structure of the cement stone in comparison with the phase composition of the cement stone without additives. The result of these changes is a significant increase in the amount of calcite, waterite and a significant decrease in the amount of portland. The authors establish that the effective joint work of the reinforcing component of the osprey with the cement matrix is possible with a limited amount of osprey in organic and mineral compositions.