- University of Illinois at Urbana-Champaign
Common practice overlooks the highly heterogeneous nature of asphalt concrete (AC). Doing so equates to disregarding the effect of material properties’ spatial variability on the field behavior of AC mixtures. This paper presents an alternative computational approach to assess the effect of AC heterogeneity on the performance of a pavement structure. Using finite elements, a three-dimensional, flexible pavement structure is subjected to a moving load. Each time the structure is modeled, a unique internal distribution of mechanical properties is assigned to the AC layer. Thus, several simulations of the pavement structure are prepared, modeling a different AC layer each time. Two sets of pavement structures were simulated, considering mechanical properties of the AC layer as having two levels of variability (intermediate and high). The results present qualitative and quantitative estimates of the actual effect of material spatial variability (i.e., the heterogeneity of material properties) on the performance of a flexible pavement structure via strain analyses. The results also highlight the importance of consistency and quality in AC compaction.