Effect of analysis procedure and sample geometry on the fatigue life results of asphalt mastics from linear amplitude sweep test.

We examine the effect of sample geometry and analysis procedures on the fatigue life results of asphalt mastics obtained using the linear amplitude sweep (LAS) test. Asphalt mastic samples are prepared using two fillers (Red mud and Limestone), one base binder (VG-30) and three filler binder (F-B) ratios (0.5, 1, and 1.5 by weight (w/w)). The LAS test is conducted on mastic samples using cylindrical and hyperbolic geometry at three different temperatures (+10 ^∘C, +20 ^∘C, and +30 ^∘C). We use the dissipated energy (DE) based approach, pseudo-strain energy (PSE) based approach, and R-based approach to calculate the fatigue life of asphalt mastic samples. The fatigue ranking of asphalt mastics at varying temperatures for each test geometry is found to be independent of the analysis procedure. PSE-based approach gives the highest fatigue life followed by DE- and R-based approaches, respectively. The effect of geometry is quantified using the variation of dissipated energy versus strain level. This study suggests that the LAS test can only characterize the accurate fatigue performance of the asphalt mastic if the amplitude of the complex modulus is less than 20 MPa. Hyperbolic geometry is found to be more effective in the quantification of fatigue damage of asphalt mastics. [ABSTRACT FROM AUTHOR]