The fatigue resistance, as a performance indicator, is of paramount importance for the selection and benchmarking of bituminous materials. The bituminous mortar can be considered as the medium that connects and envelopes the coarse aggregate skeleton, and hence will significantly influence the fatigue resistance at bulk-scale. Therefore this study presents the steps and challenges of a new testing framework to evaluate the fatigue resistance of bituminous mortars. To do so, first, a new test geometry is introduced, which will ensure cohesive failure in a predefined area. The integrity of this sample geometry is assessed theoretically through finite element simulations and by computer tomography scans. Secondly, specimens of the new geometry are evaluated experimentally using a dynamic shear rheometer, where time-sweep tests are performed on two control mortar types under various test conditions. The control mortar types are fabricated using two commercial bituminous binders, one modified and one neat binder, to evaluate the effect of binder type. The test results are comprehensively analysed using fundamental dissipated energy-based concepts but also empirical and phenomenological failure criteria, providing insights into the failure evolution. For the tested mortar types, the analysis shows good convergence with the considered fatigue models. Finally, using dissipated energy concepts led to the most consisted fatigue model, which is independent of binder type and test conditions.
Bibliographical noteGreen Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.
- Bituminous mortar
- Dissipated energy ratio
- Dynamic shear rheometer
- Fatigue resistance
- Ratio of dissipated energy change