PAVEMENT DENSIFICATION RELATED TO ASPHALT MIX CHARACTERISTICS

The primary purpose of this paper is to present the relationship between the characteristics of asphalt pavement mixtures and their Marshall job mix design values and pavement rutting or densification. Characteristics of cores taken from 24 test sites, along with their Marshall job mix design values, were correlated with the measured rut depths of the pavement. All of the pavements under study were high-type asphalt concrete with 12-ft lanes, sealed shoulders, and good drainage. The traffic load ranged from light to heavy. The pavement ages ranged from 3 to 22 yr. Relationships were established between asphalt pavement rutting and physical characteristics of the pavement core, including the voids filled, air voids, Marshall stability, and hump in the aggregate grading curve. The Marshall laboratory job mix design values of stability and flow were used to calculate a Marshall modulus. This modulus was found to relate to the rutting potential of the mixtures based on the measured pavement rut depth of the pavements at the study sites. The results presented will enable the design engineer to analyze pavement mixtures designed by the Marshall method and to predict pavement rutting based on the standard Marshall test. The results and discussion in this paper also provide insight into the relationship between mixture characteristics and the development of ruts in pavements.