Evaluation of Rheological Properties of Polymer-Modified Asphalt Binders and Mastics with Organic Additive—Imidazoline

Abstract

The article presents the results of testing the asphalt binder modified with SBS copolymer (5%) and its mixture with mineral fillers called asphalt mastics. The aim of the research and analysis was to check the possibility of using an organic additive in the form of imidazolines and to assess their impact on the viscoelastic properties of the obtained asphalt mastics. The main advantage of using imidazoline is the increased resistance of asphalt mixtures to low-temperature cracking at the top of the road route and reducing its maintenance costs. Based on the examination of the adhesion of the binder with the addition of various imidazolines to the aggregate, a selection was made from six analyzed subtypes. One of them was selected for further research. The tests were carried out in a dynamic shear rheometer in a wide temperature range from −36 °C to 82 °C, determining the most important parameters of the tested materials, i.e., dynamic shear modulus (|G*|), phase angle (δ) and the non-recoverable creep compliance (Jnr). The test results and their analysis confirmed the beneficial effect of imidazoline on the viscoelastic properties of mastics in the low-temperature range, even at the lowest content of 0.2%. Based on the results of the determination of Jnr and |G*|/sinδ in the range of high operating temperatures, no significant deterioration in permanent deformation parameters was observed. Moreover, the use of imidazoline reduces technological temperatures during the production of HMA used in the pavement and, therefore, reduces CO2 emissions into the atmosphere.