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Introduction. In the process of soil compaction it is important to have information about the current density of the layer, as it enables to quickly adjust the load on the compacted material. The field methods of compaction quality assessment do not cope with this task, as they make point estimation within the pavement area. Therefore, continuous compaction monitoring systems installed on vibratory road rollers are becoming increasingly common. The systems developed by BOMAG and AMMANN require, among other things, the phase angle between the exciter force and the roller movement to calculate the compaction quality index. The phase angle is determined by the unbalance position sensor, which is very labor-intensive. In addition, continuous compaction monitoring systems include an accelerometer. The purpose of this paper is to develop an indirect method for calculating the phase angle from accelerometer readings.The method of research. In order to achieve the purpose of the work, a roller-soil single-mass model in a typical mode for vibratory rollers (periodic loss of contact) has been studied. As a result of modeling it has been found that the reaction of the compacted material has the main influence on the vertical component of a roller acceleration and practically does not affect the horizontal component. This is confirmed by the experimental data.Results. The phase angle can be determined by mutual correlation of the horizontal and vertical acceleration signals of the roller obtained with the accelerometer.Conclusion. The study proposes a new method of calculating the phase angle between the exciter force and the roller displacement, which eliminates the direct measurement of this angle. The calculation of the angle is based on the readings of a two-axis accelerometer installed on the road roller. The proposed method enables to simplify the system of continuous compaction control and reduce the labor intensity of phase angle measurement.

Introduction. At the heart of the creation and improvement of robotic road construction machines and complexes are mathematical modelling methods, the use of which is justified both in the development of the machines themselves and mathematical models that describe the turning processes and determine the movement of the machine along a given trajectory.The method of research. The article presents a generalized design scheme for the rotation of a three-axle road roller, which reflects its main geometric and kinematic characteristics. On the basis of the design scheme, a mathematical model of the rotation of the skating rink was compiled. As a result of the developed mathematical model, a program code was built in the MATLAB software product, which formed the basis of theoretical studies that made it possible to fully study the influence of the design and operational parameters of the machine on the motion trajectory and positioning accuracy.Results. The calculated dependencies have been obtained to determine the influence of such parameters as the speed of the road roller, the angular speed of the drum rotation on the distance of rebuilding on a parallel course and on the displacement of the rotary drum, that is, on the trajectory and positioning accuracy of the road-building machine.Conclusion. On the basis of the design scheme, a mathematical model of the rotation of the roller was compiled, as a result of which studies were carried out aimed at studying the influence of the design and operational parameters of the machine on the trajectory of the road roller and the accuracy of its positioning on the construction site when performing technological operations.

Simulation is an important step in the design of new road roller models. In the process of modeling, it is possible to exclude options that do not allow obtaining the optimal structure or parameters of the designed machine. To carry out this stage, it is necessary to have information about the range of values of the design parameters of the roller, the main of which is the operating weight. The mass per axle of a road roller depends on its operating mass and consists of the mass of the frame part and the mass of the drum, the value of which is required in the dynamic simulation of the vibrating drum-compacted material system. Manufacturers of road rollers do not give the drum weight in their technical documentation, so it is difficult to determine its value. In the proposed study, the analytical dependence of the drum mass on the technological parameters of the vibrating and oscillating roller was obtained, and the statistical analysis carried out showed that for calculations the drum mass can be taken equal to 20% of the operational roller mass. As a result of the analysis of the system of forces acting on the drum, it was found that with the same mass, the oscillating drum, in comparison with the vibration, develops a greater driving force. In addition, the impulse of the driving force of the oscillating drum is higher than the impulse of the vibratory drum. The research results can be used to simulate the interaction of a smooth drum of a road roller in the design of new machine models.

The lack of a common methodology on compaction theory stimulates developers of road construction equipment to create various approximate methods for their calculation, the number of which, at the present time, is comparable with the nomenclature of the proposed designs of rollers. The article presents the analysis of the deformable shell behavior of a road roller, and the compacted material under its compacting roller, in a situation when a rigid circular shell of the roller is replaced by a forcefully deformable elliptical shape, which, unlike the circular design, allows variation, adjustment and optimization of the road roller impact on the material to be compacted.

Asphalt concrete, being a durable composite material, has found wide application in construction. Especially it is necessary to highlight its use as a road surface as a common and popular material. The process of compacting asphalt concrete by road rollers is a complex process, with its own specifics and disadvantages. The purpose of the research is to substantiate the availability of technologies for the continuous compaction of asphalt concrete pavement with a road roller. This article analyzes the drawbacks of current technology (reciprocating compaction with braking) and discusses possible solutions to problems by progressively compressing the mixture. The scheme of interaction between the roller of the roller with the compacted asphalt-concrete mixture is presented, the negative consequences of the reciprocating motion of the roller and sudden braking on the laid floor are described. The interrelationship of defects and their causes due to the fault of the roller or its driver were examined and analyzed. The expected effect from the introduction of the translational seal instead of the cyclic one is presented. In conclusion, the non-stop compaction of asphalt concrete pavement with a road roller is justified, and the advantages and disadvantages of various rolling technologies are described.

The article is devoted to solving the fundamental and applied problem of nonlinear structural mechanics of machines by introducing into the drum two additional stop cylinders with supporting rollers at the end and adjustable length, providing a given elliptical or circular shape of a flexible shell with a smoothly variable geometry in the area of its contact with compacted pavement material. Compaction of soil, gravel and asphalt concrete in the sphere of road is not only an integral part of the technological process of the roadbed, road foundation and surface construction, but it is actually the main operation to ensure their strength, stability and durability. The quality, cost and speed of road construction, the possibility of using fundamentally new technologies, structures and materials is largely determined by the availability of modern road machinery.

This article refers to the reliability of road rollers used in a selected roadworks company. Information on the method of road rollers service and how the service affects the reliability of these rollers is presented. Attention was paid to the process of the implemented maintenance plan with regard to the machine's operational time. The reliability of road rollers was analyzed by determining and interpreting readiness coefficients.

The paper presents a new simple mathematical model of a fundamental and applied elasticity theory problem, considering the stress-strain state of road-roller working members with elliptic surfaces and the road-building material interacting with them. The derived mathematical relations and the developed calculation theory prove the possibility of adjusting (optimizing) the parameters of contact interaction of flexible working members in roadrollers with elliptic surfaces, with the compacted layer by means of variating the design-constructive dimensions of semi-axles of the ellipseshaped surface of the roll under service conditions, thus adjusting force action on the compacted road-building material. The paper deals with an operation peculiarity of flexible working members with elliptic surfaces, offers a selection of materials and determines geometric parameters of flexible working members with elliptic surfaces. Based on the analysis of stress-strain state of the roll, two cases are considered suitable for constructive realization of the examined mathematical model.

Subject: management of operating modes of road-building machines, taking into account the implementation of the concept of information modeling of the road. We have reviewed the status and the development problems for directions of improving the control systems of road-construction machine processes. In this work we focus on the road construction stage “laying asphalt-concrete - compaction”, the effective control of which can lead to significant improvement in the quality of road surfaces, increase of durability and reduction of defects in pavements. Research objectives: rationale and directions of realization of the concept of intellectualization of the road construction management. Materials and methods: analysis of the shortcomings of construction of asphalt-concrete pavements, analysis of the methods of workflow management of road-building machines. Results: we have substantiated the methodological background for the development of intellectual control systems of roadbuilding machines. Conclusions: we considered possible ways of introducing the concept of intellectualization of management systems for road-building machines. [ABSTRACT FROM AUTHOR]

This paper studies the existing hot-mix asphalt compaction technology and points out that designation of the appropriate asphalt rollers and working parameters has to be performed in accordance with mechanical characteristics of the layer. A way to avoid defects during the rolling process is proposed based on determination of material properties before starting asphalt compaction. Due to a large variety of used types and compositions of asphalt mixes, determination of their characteristics by practical consideration is impossible. The study considers the method for determination of asphalt mechanical properties based on implementation of the time-temperature superposition principle. A procedure for dynamic modulus computation at each stage of the compaction process has been developed. Comparison of calculation output with experimental data verifies the determined relation for dynamic modulus. Consideration of this parameter allowed developing a new mathematical formulation for the rheological model of roller-asphalt interaction. The conclusion is drawn pointing that application of the approach for the development of compaction technology based on calculation of dynamic modulus will result in enhanced pavement quality along with reduced labor expenditure and higher cost saving.