Assessment of HMA Air-Voids and Stiffness Based on Material Dielectric Values

ABSTRACT The determination of air voids is one of the most important aspects in the design of Hot Mixed Asphalt (HMA). The stiffness of HMA is also of paramount importance in assessing the mechanical properties of the mixes in terms of pavement performance. The relationship between air voids and stiffness has been recognized. In addition, HMA can be described as composite materials characterized by their dielectric values. The objective of this paper is to study the interaction between dielectrics and voids or stiffness of HMA materials. Based on the asphalt mixes dielectric values as measured in the laboratory simple formulas were developed for the estimation of voids and stiffness. The suggested approach could be used as a promising practical procedure towards the assessment of HAM voids and stiffness given that the dielectrics measurement seems to be a quick and easy method.