The effect of different loading patterns on the resistance to shear flow of hot mix asphalt

The aim of this study was to evaluate the performance of hot mix asphalt against shear deformations. Loading axles (single, tandem and tridem) as well as vehicle speed were considered as research variables. The combination of research variables creates different loading scenarios with different loading pulse times. Using theoretical principles, loading scenarios similar to the field mode were simulated. Then, using the repeated load uniaxial test (RLUT), a quantitative analysis was performed on the mentioned variables. Flow number (FN) and tertiary flow (TF) were used as quantitative output parameters to analyze the test results. In addition, the regression coefficients of the power-law model represent the effect of initial densification and shear flow. It was observed that at higher speeds and in the mode of multiple axles, the initial densification had more effect on the permanent strain compared to the effects of the shear flow. On the other hand, in the single axle, the shear flow was the dominant factor at all speeds. At the middle speed (60 km⁄h), the shear flow (the slope) was the dominant parameter for the tridem axle. Low pulse times, high speeds and proximity of the load impact peaks can cause higher initial densifications in multiple axles. It was also indicated that by increasing the number of axles, values of the FN and the TF, and the value of the interval between these two parameters reduced. This reduction became more tangible by increasing the number of axles from single to other axle modes. In all axle modes, by increasing the speed, the FN and the TF increased. The rate of these increases was higher when transitioning from low speed (20 km⁄h) to middle speed (60 km⁄h) was more intense. Therefore, low speeds had more destructive effects. Thus, higher speeds reduced the destruction effects of multiple axles loads and increased the service life of the mixtures, and improved their performance against shear deformations.


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  • Accession Number: 01761026
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Nov 19 2020 3:26PM