The influence of boundary conditions on the healing of bitumen

Damage in pavements is known to reduce over time when the material is left to rest, this phenomenon is identified as healing. It has been shown that healing has a large influence on pavement performance. However, as the healing mechanism is not fully understood, there is currently no accepted method available to assess the healing performance...

Het healingmechanisme van bitumen nader verklaard

Asfalt heeft de aantrekkelijke eigenschap dat het zichzelf kan herstellen na schade. Er is echter tot op heden geen betrouwbare methode om de healingcapaciteit van een asfaltmengsel te bepalen. Bij het healingproces van een discrete scheur spelen twee processen een rol, namelijk het in contact komen van de oppervlakken van de scheur; het...

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...

Chemomechanics of Damage Accumulation and Damage-Recovery Healing in Bituminous Asphalt Binders

As a contribution to the development of mutli-scale multi-physics approaches to modelling pavement performance, the present thesis considers the topic of damage accumulation accompanied by damage recover self-healing of the bituminous asphalt phase of pavement systems. It is found insightful that by adopting Hveem’s [1943] concept of attributing...

Healing van Asfaltmengsels: Onderzoek naar een pragmatische proefmethode

Het zelfherstellend vermogen, of de healingscapaciteit, van asfaltmengsels wordt in de meeste ontwerpmethoden voor wegverhardingen meegenomen. De kennis over dit zelfherstellend vermogen is gebaseerd op ervaringen en onderzoeken uit het verleden en de werkelijke mechanismen erachter zijn niet bekend. Hierdoor is het moeilijk om voor nieuwe...

Fatigue and healing performance of bituminous binders and mixtures for road pavement: Results of re-road project

An asphalt mixture is believed to be a partial self-healing material. For asphalt pavement design, this characteristic is taken into account as a shift healing factor. Healing during rest periods will result in a longer structural design life for the mixture in situ, compared to the fatigue life determined with a continuous sinusoidal test in...

Self-healing short-circuits in organic light-emitting diodes and solar cells

Organic materials open the way for large-scale applications of Organic Light-Emitting Diodes (OLED) and solar cells (OPV). These materials can be large-scale processed using printing and coating on rigid and flexible substrates. The resulting devices can therefore be fabricated at low cost for various applications. Production yields suffer,...

Resistance of cracked concrete healed by means of polyurethane against chloride penetration

A lot of damage is reported for constructions in marine environments. Marine environments are very aggressive, because of the high chloride concentration in sea water. Chlorides affect durability by initiating corrosion of the reinforcement steel. When cracks appear in the concrete structures, chlorides will penetrate faster and will initiate...

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

For asphalt pavement design in Belgium, healing is taken into account as a standard shift factor, representing the effect of rest periods between loadings of traffic. Because nowadays Reclaimed Asphalt Aggregate (RA) is widely used in hot mixtures, a new validation of the healing factor is needed. Given the lack of test results and a standard...

Induction Healing of Porous Asphalt Concrete

Porous asphalt shows excellent performance in both noise reduction and water drainage. Although porous asphalt has these great qualities, its service life is much shorter (sometimes only half) compared to dense graded asphalt roads. Ravelling, which is the loss of aggregate particles from the surface layer, is the main damage mechanism of porous...

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...