Project Details

The objective of this study is to develop a database of dynamic moduli values and their variability for asphalt mixes used in North Carolina using both the uniaxial compression test and the indirect tensile test. In addition to the dynamic modulus testing of the representative mixes, surrogate methods will be evaluated, including the impact resonance method and Witczak's predictive equation. These methods may be acceptable for the design of mixes and pavements that are normally subject to low traffic volume.​

The dynamic modulus database to be developed from this project will allow the NCDOT Pavement Management Unit (PMU) to evaluate the new AASHTO pavement design guide in the short term and will provide necessary input for the design of asphalt pavements using the new design guide in the long term. Also, this database will provide necessary information to use the dynamic moduli values in forensic studies and overlay design. The experience and database obtained from this research will also help the NCDOT Materials and Tests Unit (M&T) implement the dynamic modulus testing in its own laboratory.

The primary objectives of the research study are to: Develop a database for typical dynamic moduli values and their variability for asphalt concrete mixes used in North Carolina.Develop/evaluate a simple surrogate test or prediction method for determination of the dynamic moduli of asphalt mixes.The following primary products are expected from this research study:A database containing the values and variability of dynamic moduli.A refined complex modulus test protocol that is in accordance with the recommendations from the NCHRP 9-19 and 9-29 research teams.A verified or calibrated form of Witczak's predictive equation for the dynamic modulus.The relationship between the dynamic modulus measured from the complex modulus testing and the dynamic modulus of elasticity measured from the impact resonance method.The relationship between the dynamic modulus measured from the uniaxial compression testing and that measured from the indirect tensile testing.​