It is postulated that the fatigue test best replicates the loading environment of asphalt in the pavement. The more severe constant stress mode of loading was employed for this study. The results showed that the retained strength measurement, in this case the retained flexural modulus, varied between 64 percent and 123 percent. The results also showed that the fatigue life varied by many orders of magnitude between performance extremes. The absolute cycles to failure varied by many orders of magnitude between the best and worst performers (i.e. between 4 and 1300 thousand cycles). The work also showed the moisture sensitivity of the bitumen aggregate system does vary both with aggregate type and bitumen source. The effect of the anti-strip additive was likewise sensitive both components of the system and some control systems with no additive gave the best performance of the particular system. The test is considered to be a research tool at this stage and significant field calibration and validation is required before implementing in specifications. (Author/publisher) For the covering entry of this conference, please see ITRD abstract no. E208431.
Samenvatting