Anti-cracking Layers with Highly Modified Binders (HiMA) for Maintenance of Asphalt Pavements

Maintenance of asphalt pavements after many years of operation requires various repair techniques. In the case of the road with a significant degree of distress and a wide range of fatigue and thermal cracking, special layers with anti-cracking properties have been used. Such a layer can be a single overlay on the old pavement, or it can be a layer that blocks crack propagation and is placed between the old pavement and the new asphalt layers. This paper describes three experimental field sections with different asphalt mixtures containing HiMA binders (Highly Modified Asphalt), constructed between 2013 and 2016. The aim of the research programme was to select a suitable binder for asphalt mixtures used for overlays on old asphalt pavements. Asphalt mixture performance used in these sections was tested for fatigue cracking resistance by SCB, TSRST and rutting resistance at 60 ℃. The binders’ properties were studied using methods compliant with European Standard and US Performance Grade. Finally, the softest variant of the HiMA binder was chosen to perform the test sections. During pavements’ service life, the performance of the sections was periodically observed, and after 7–10 years, the effectiveness of the applied solutions was evaluated. A unique feature of asphalt mixtures containing the HiMA (especially soft grade) binder is the ability to deform plastically without cracking. The conclusions of the field section evaluation are reflected in the results of HiMA binders and mixtures testing.