Micro-mechanical analysis of high modulus asphalt concrete pavement
The objective of this study is to investigate the micro-mechanical characteristics of High Modulus Asphalt Concrete (HMAC) pavement structure under loads. The Discrete Element Method (DEM) was employed in this study to build the models for HMAC pavement and conventional asphalt pavement structures. The laboratory tests and DEM simulations of uniaxial compression tests were conducted on the materials of HMAC pavement structure layers. To simulate the mechanical behavior of the asphalt mixture, micro-parameters were adjusted to fit with the strain–stress curve results from lab-test. The displacement and stress distribution in vertical and horizontal directions, and the shear stress in the horizontal direction were analyzed for the HMAC pavement and conventional asphalt pavement. The results showed that the maximum vertical displacement of HMAC pavement (0.25–0.293 mm) was less than that of the conventional asphalt pavement (0.3–0.324 mm). The application of HMAC decreased the vertical stress in all structural layers except the upper surface layer. The HMAC decreased the horizontal stress in the subbase layer. Though the HMAC pavement had a slightly greater horizontal shear stress in the upper and middle surface layers than the conventional asphalt pavement, its shear resistance was. Therefore, the results indicated HMAC layer can enhance the resistance to deformation and reduce the rutting potential in asphalt pavement.
Keywords: Asphalt pavement, Micro-mechanical analysis, Discrete Element Method (DEM), High Modulus Asphalt Concrete (HMAC),