Influences of intelligent compaction uniformity on pavement performances of hot mix asphalt

Abstract

Conventional pavement analysis and design methods are based on the homogeneous or uniform material model such including the multi-layered analysis program and AASHTO design methods. With the Intelligent Compaction (IC) technology on hot mix asphalt (HMA) involved in recent years, the compaction uniformity of material property can be quantified. This paper intends to study the effects of compaction uniformity on pavement performances using the Bomag IC Evib – a measurement of elastic moduli with 100% coverage of the compaction area. The three dimensional (3-D) finite element (FE) model was built to simulate pavement responses with the heterogeneous HMA moduli derived from the field IC measurements. Then the Mechanistic-Empirical Pavement Design Guideline (M-E PDG) models were used to predict HMA performances of rutting and fatigue life. The geostatisical semivariogram model was studied to evaluate the uniformity of predicted performances. Different from conventional pavement analysis and designs, spatial-distributed heterogeneous moduli of the asphalt layer were considered in this work. Results show that spatial uniformity of material moduli affects pavement performances in terms of the distress severity and uniformity. Less uniform material moduli result in higher rutting depths and shorter fatigue lives. For the case study in this paper, the mean and peak values of fatigue lives for the heterogeneous model are 38.2% and 0.1% of those for the uniform model. A pavement section with overall lower material moduli does not necessarily correspond to inferior performances as the effects from uniformity of material property may dominate other factors. Therefore, it is recommended that the uniformity of pavement layer properties that emulate the typically more variable service condition be considered in future pavement designs and performance predictions.