Phase-Separation Characteristics of Bitumen and their Relation to Damage-Healing

During the service life of flexible asphalt pavements, asphalt concrete degrades due to traffic loading and environmental conditions like temperature, rain, oxidation, ultraviolet-radiation from the sun. All these environmental factors have adverse effects on the performance of bitumen, which is the binder of asphalt concrete. They are known to...

Impact of maltene and asphaltene fraction on mechanical behavior and microstructure of bitumen

As a widely accepted concept, bitumen consists of four fractions that can be distinguished by their polarity. Highly polar asphaltene micelles are dispersed in a viscous phase of saturates, aromatics and resins (maltene phase). Different concentrations of asphaltenes in the bitumen result in a range of mechanical response properties. In an...

Turning Back Time: Rheological and Microstructural Assessment of Rejuvenated Bitumen

Countermeasures to the ageing of bituminous asphalt binders is a highly important topic, both for service-life extension of asphalt ‘in the field’ and for recycling old pavements (RAP) into new structures with similar functional requirements as the original structure. Usually this is achieved by applying additives that restore the adhesive and...

First Observation of the Blending Zone Morphology at the Interface of Reclaimed Asphalt Binder and Virgin Bitumen

One of the challenges in designing recycled asphalt mixtures with a high amount of RAP is to estimate the blending degree between RAP binder and the added virgin bitumen. The extent of blending is crucial in this case as asphalt concrete response is influenced by the final binder properties. This paper focuses on the evaluation of interaction...

Temperature induced healing in strained bituminous materials observed by atomic force microscopy

Bitumen is the binder in the composite material named asphalt concrete. Under cyclic mechanical loading of traffic passing over the pavement, eventually damage will initiate in the pavement, leading to eventual structural failure. This damaging process is accelerated by time dependent change of the mechanical properties of asphalt concrete due...

Is Atomic Force Microscopy suited as Tool for fast Screening of Bituminous Materials? An Inter-laboratory Comparison Study

Bituminous binders are known to have microstructures at typical length scales of micrometers. This microstructure can be probed with Atomic Force Microscopy (AFM). Now that worldwide several research groups are reporting AFM results on bitumen, it is becoming important to improve the understanding of the reproducibility and objectivity of the...

Vergelijkend AFM Onderzoek: Microstructuur van bitumen in relatie tot healing

In this report we present the background, the scientific and experimental approach and the results of AFM experiments performed on two different batches of bitumen. The specific bitumen researched in this project has also been studied in the context of the InfraQuest project ‘Pragmatisch Healing Onderzoek’. It has been known for quite some time...