Machines and equipment for asphalt pavement milling are widely used throughout the world. With the growth of road construction, the demand for this class of machinery also rises. At the same time, the optimization of design and technological parameters of the milling machines is impossible without a comprehensive study of processes of milling asphalt concrete with the working elements of a cutter. The article provides a brief overview of different approaches to find out the loads on the working bodies of various machines, as well as indicates the advantages and disadvantages of these approaches. We describe the design of a pendulum stand used to study the processes of milling asphalt concrete with a single tooth cutter. We also describe the method of operation of such a stand. The design of the pendulum stand allows us to determine the cutting work, the average, and the instantaneous cutting forces. The work also provides the result of tests of cutting elements during their interaction with samples of asphalt concrete of different grades that are widely used in road construction. We also show the non-linear dependence of cutting resistance forces on the temperature and thickness of penetration of a cutting element. It is noted that working with a slight tooth penetration leads to low energy efficiency of the work process. It is also noted that temperature affects cutting resistance forces significantly less in asphalt concrete containing high amount of gravel.

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Stresses in soil are a link between all parameters and operation modes of a vibratory roller and deformations at different depths of the soil. The paper presents a research technology and the results of measuring stress amplitudes in soil at depths of 0.15, 0.3, and 0.5 m at different dynamic moduli of soil deformation Evd. It is established that in the surface layer (0.15 m deep) within a single loading cycle, the duration of stress buildup phase is 1.5…2 times lower than the duration of stress relief phase, and this ratio increases with compaction. Within one roller pass in the surface layer (0.15 m deep), the increase period of the amplitudes of separate stress cycles is 1.2…2 times longer than the decrease period of those, and this ratio also increases with compaction. It is established that the vibration impact of a roller, similarly to the impact loading of soil with a tamper, affects how the stresses change during the relief phase at each impact cycle. This change is the same as how the stresses change during the relief phase in a surface layer (0.15 m deep), which confirms that it is possible to apply the provisions of the dynamic theory of plasticity not only for impact, but also vibratory and vibro-impact soil compaction modes. The obtained results can be used to update and verify the existing and future mathematical models of soil compaction with vibratory rollers.

The paper presents a three-mass rheological model of the system "soil – vibration plate base – vibration plate frame". The rheological model makes it possible to reproduce different modes of interaction between the vibratory plate base and soil: with different types of plate decoupling and without decoupling. We verify this model by comparing the experimental values of the vertical oscillation span of the base and frame of the Zitrek CNP 20 vibrating plate with the previously calculated values. As a whole, the calculated values of the span of vertical oscillations of the base and frame of the Zitrek CNP 20 vibrating plate correlate with the experimental data in the range of the dynamic modulus of soil deformation of 13…30 MPa. During the experiment we used the rheological model and obtained results are as follows: the mass of the vibrating plate (50; 150; 250; 350; 450; 550; 650; 750 kg), the coefficient of the elastic resistance of soil (30; 60; 90; 120 MN / m), and the coefficient of viscous resistance of soil (100; 200; 300 kN • s / m). The total number of combinations of parameters was 96. The processed results of the computational experiment provide the regression dependences for calculating the maximum soil reaction force, the time of soil loading (increasing the values of the reaction force of soil) t1, and the time of soil unloading (decrease the values of the reaction force of soil) t2. The simulation results show that, within one exposure cycle, the soil loading time t1 is less than the soil unloading time t2. The ratio t1/t2 is influenced by the weight of the vibratory plate, as well as the factors of elastic and viscous resistance of soil. This feature (t1/ t2  1) is typical for both vibratory rollers and rammers, which is confirmed by the results of the relevant experimental studies. The obtained regression dependences of parameters Fs, t1, and t2 on the vibratory plate mass and the factors of elastic and viscous resistance of soil are important for calculating the distribution of stresses and strains on the depth of the compacted soil.

Rheological modeling of how the elements of a vibratory roller during soil compaction interact with each other allows the optimization of parameters of the roller and soil compaction modes based on the study of the obtained model, as well as the improvement of the soil compaction continuous control system, and the solution of other practically important tasks. To verify the models, it is required to compare the calculation results for the models with experimental data. The paper includes the results of experimental studies of the acceleration range for the vibratory drum of the DM-617 vibratory roller during soil compaction in the steady vibration mode, when the vibration is turned on, and when it is turned off. It is established that during the compaction of the soil in question in the range Evd = 14…25 MPa, the range of vertical movements and accelerations of the vibratory drum in the steady vibration mode does not depend on the soil density. When the vibration is turned on, the vertical movements and accelerations of the drum is 1.5…2 times higher than those of the steady mode. When the vibration is turned off, the vertical movements are increased by 1.5…2 times when passing the resonance zone, and the drum accelerations do not exceed the range of those in the steady vibration mode. The obtained results allow the mathematical models of vibratory rollers during soil compaction to be verified not only in the steady vibration modes, but also in transient modes, including passing the resonance areas when switching the vibration on and off.