Experimental and numerical study of asphalt material geospatial heterogeneity with intelligent compaction technology on roads

Abstract

In the conventional structural analysis and design of highway pavements including the mechanistic-empirical pavement design guide (MEPDG), the layer properties are considered uniform spatially. This research studies the geospatial heterogeneity of asphalt material property and its influence on structural responses with the intelligent compaction (IC) technology on road construction. Instrumented with the satellite navigation system, accelerometer and computer system, the IC roller measured the material stiffness with 100% coverage. A three-dimensional finite element (FE) model was developed to simulate pavement responses with heterogeneous Bomag Evib as elastic moduli of asphalt materials under vehicle loading. This material model considers heterogeneous material properties with geospatial distribution that more closely reflect the actual field conditions on a typical roadway. The statistics and geostatistical semivariogram model were studied to evaluate the heterogeneity of material moduli and structural responses. A coefficient of semivariogram (Cova) index is proposed to quantify the geospatial heterogeneity. Modeling results demonstrated that geospatial heterogeneity of material elastic moduli, rather than commonly used univariate statistics, affects structural responses spatially in a nonlinear fashion. Heterogeneous moduli distribution results in inferior responses than uniform model. Cova has close values and trends with that of the coefficient of variance for the analysis area with small-space, and it could be used to quantify the heterogeneity. Therefore, the geospatial heterogeneity of material property is recommended to be considered in future pavement analysis to account for the in-service conditions.