The Effect of Ageing on the Fatigue and Healing Properties of Bituminous Mortars

Nowadays, reclaimed asphalt aggregate is often used in new asphalt mixtures. In Flanders, up to 50 % of the binder content is allowed to be originating from reclaimed asphalt. However, the effect of this aged binder on the fatigue and healing properties of the asphalt mixture is questioned. A procedure for the ageing of asphalt mixtures, mortars and binders in the laboratory was developed. The aim of this test procedure was to age the binder, in such a way that its rheological and chemical properties are similar to those of field-aged binders. In this way, a reproducible material with known composition and origin is available for further testing. The chemical properties were evaluated by Fourier Transform InfraRed spectroscopy. The effect of ageing on the fatigue and healing properties of bituminous mortars was investigated. In this research, the mortar is composed of bituminous binder, filler and fine sand fraction. Virgin, laboratory-aged and mortars containing binder from reclaimed asphalt were manufactured. Cylindrical mortar samples were tested with the Dynamic Shear Rheometer. Torque-controlled fatigue tests, with and without rest periods, were conducted and demonstrated that the fatigue life increased with the introduction of rest periods between loading cycles