Asphalt Concrete Stiffness Modulus Estimation Utilizing an Algorithm Approach: Fid-Bau Portal

Asphalt Concrete Stiffness Modulus Estimation Utilizing an Algorithm Approach

Plati, C. / Georgouli, K. / Loizos, A.

The stiffness modulus is an important factor for asphalt mixture characterization, and multiple procedures and theories have been developed, as shown in international literature, to determine the stiffness moduli. Among these, the dynamic modulus (E*) has played an increasingly important role in recent years, with the E* being introduced as a key element in the Mechanistic Empirical Pavement Design Guide (MEPDG). The determination of the modulus, however, is a time-consuming activity and this has led to the development of multiple algorithms for the reliable prediction of E*. Among these is the Witczak 1-37A model that it is currently used for the estimation of E* in the MEPDG. As such, this algorithm was selected for use in the present research study, with the aim to examine and evaluate the ability of Witczak's 1-37A model's ability to estimate the hot-mix asphalt (HMA) dynamic modulus of locally produced asphalt concrete mixtures. The E* derived utilizing the algorithm were compared with those found through laboratory testing. Results of these comparisons indicated that in general the predictive modulus equation works well when a multiplier is set to account for the uniqueness of local mixtures. However, the stiffness modulus based on the indirect tensile stiffness approach (Sm) as described in the EN standards, is still widely used. So a preliminary study was further performed to investigate the relationship between E* and Sm. Related comments for further implementation are included in the present paper.