MODELING AND INVESTIGATION OF THE INFLUENCE OF LOADING MODE ON THE DEFORMATION PROCESS OF ASPHALT CONCRETE MATERIALS

The article considers a problem of calculating the deformations of forward and reversed creep tension of rheonomic materials. The hereditary theory of creep by Yu.N. Rabotnov is used to describe the nonlinear deformation process. Proposed a method for determining the necessary material characteristics from forward and reversed creep data. During the experiments, there were tested two batches of asphalt concrete samples. Also, was shown behavior of asphalt concrete at cyclic increasing and constant loading modes. At a temperature T = 24◦C were tested 10 samples at cyclic increasing loading mode. Cyclic stresses were equal to 0.041; 0.074; 0.111; 0.148; 0.183 MPa and duration period between loading and relax period were chosen to be 570 seconds. At cyclic constant loading were investigated individual samples for the parameters of forward and reversed creep at stresses of 0.041; 0.117 MPa. Then, investigated the affect of reloading two reversed creep process of asphalt concrete samples. From first batch of samples were tested 9 samples before destruction with a period 65 seconds: forward creep of samples at σ = 0.3053 MPa for the following 5 seconds; reversed creep at σ = 0 for the following 60 seconds. From the second batch of samples were tested 11 samples of asphalt concrete before destruction with a period 70 seconds: forward creep σ = 0.3053 MPa for the following 10 seconds and reversed creep at σ = 0 for the following 60 seconds. Test results showed that the level of return of second batch increased than the first batch of samples. In the work were tested 5 samples of asphalt concrete according to the direct tensile scheme until a complete failure. Test temperature was T = 22−24◦C. For each level of loading with constant rate: 0, 6519; 0, 4678; 0, 0580; 0, 0489; 0, 0055 MPas−1. Using experimental data, were found parameters of the deformation at different constant rate of loading. As a result, all samples fractured brittle at small deformations.