Incremental Rutting Prediction with Asphalt Mixture Shear Properties

Abstract

It is a purpose of the article to present the correlation between two devices developed to measure shear properties of asphalt mixtures. The shear properties are measured by well-known Superpave Shear Tester and developed Uniaxial Shear Tester. The material characteristics are determined from two test methodologies. Shear small amplitude oscillation test, known also as a frequency sweep shear test and repeated shear tests are utilized. The properties, characterizing the complex moduli, are determined with the use of sigmoidal function used in Mechanistic Empirical Pavement Design Guide (Hallin in NCHRP 1-37A guide for mechanistic-empirical design. National Cooperative Highway Research Program, 2004). The Gamma function (Deacon et al. in Transp Res Rec J Transp Res Board 1806:9–18, 2002) is used to determine the properties from the repetitive shear tests. The CalME program is utilized to perform the incremental recursive simulations under three selected climate conditions, two levels of traffic loading and two pavement structures. On the basis of simulated data comparison was found the optimal correlation coefficient for UST device. Calculated p-value of Welch-modified two sample t-test for the distributions of predicted rutting from UST and SST test result suggests that surface rutting predicted by using UST and SST test results are statistically equal with high p-values. Thus, the data from the proposed UST test equipment can be used for mechanistic-empirical (ME) pavement design and will provide rutting predictions that are statistically equal to the predictions for SST. The predicted rut depth was also found to be well correlated with accumulated equilibrium compliance.