Effects of Tire Inclination on the HMA Pavement Shear Stress-Strain Response: 2-D Computational Modeling

In hot-mix asphalt (HMA) pavements, rutting failure due to shear deformation is often more prevalent at intersections with turning and/or stop-go traffic, particularly when subjected to slow-speed heavy traffic loading and high temperatures. In this study, computational simulations using the PLAXIS software, were conducted based on a two-dimensional finite element (FE) and linear elastic analysis to investigate the effects of tire inclination (turning traffic) on the HMA pavement shear stress-strain response. An in-service Texas highway (US 59) with actual measured material and field data was utilized as a case study. Variables investigated in the modeling included HMA layer thickness, temperature, and HMA modulus, tire inclination angle, and HMA density. Overall, the analysis indicated that tire inclination and temperature, and HMA modulus have a significant effect on the location and magnitude of shear stress-strain responses within a pavement structure. At intersections with turning traffic that represents the highest tire inclination angle, the maximum shear stresses and strains occur at the pavement surface and are more critical under low HMA moduli values at high summer temperatures. While more computational modeling including 3-D visco-elastic analysis is still required, preliminary conclusions from this study suggest that intersections are more susceptible to surface shear failure and permanent deformation compared to other road sections.