Determination of Input Data for Oklahoma Sma Mixtures for Use in the MEPDG

Abstract

The objective of this research project was to compare the performance of Oklahoma SMA mixes to conventional superpave (S-4) mixes and to develop input data of SMA for use in the new mechanistic-empirical pavement design guide (MEPDG). To accomplish this objective, SMA and S-4 mixtures were collected from different parts of Oklahoma and were tested for dynamic modulus. These dynamic modulus values were then used in the MEPDG software to compare the performance of Oklahoma S-4 and SMA mixes. * Test temperature had a significant effect on measured dynamic modulus values. * Stiffness of both S-4 and SMA mixtures decrease as temperature increases. * Mix type had a significant effect on measured dynamic modulus values. * Both the measured and predicted dynamic modulus values of S-4 mixtures were greater than SMA mixtures. This indicates that the S-4 mixtures tested in this project were stiffer than SMA mixtures. * The output of the MEPDG software showed lower distress values for the S-4 mixtures than SMA mixtures. This result contradicts all the literatures reviewed in this research project. Literature showed that SMA mixtures perform better than conventional mixes in every aspect. * The MEPDG should not be used to design pavements constructed with SMA until the program can be recalibrated or the results verified.