FATIGUE BEHAVIOR OF BITUMINOUS MIXTURES UNDER REPEATED LOADING IN LOW STRAIN LEVEL

Abstract

A uniaxial fatigue test was used to investigate whether an endurance limit exists in asphalt mixtures. The level of strain at which no increase in fatigue damage occurs was estimated from changes in phase angle during the fatigue test, and investigation was performed at strain levels above and below this level. The number of load applications to failure was estimated from the rate of stiffness change observed in the present test on the basis of the relationship between the rate and the number obtained from existing studies. The test results indicate that there is no endurance limit in dense-graded asphalt mixtures (13) at 10°C when strain is 20μm/m or greater.