Language: English The Challenge At the outset the asphalt paving process seems to be simple. Trucks deliver hot mix asphalt from plants to the construction site. There the asphalt is loaded on asphalt pavers that evenly spread the asphalt. Finally, compactors compact the asphalt to its required density. Despite this relatively structured process our research shows that there are significant dis...

Conductive alginate capsules encapsulating a bitumen rejuvenator (HealRoad capsules) has demonstrated good healing abilities in pure and mortar mixes. HealRoad can efficiently heal damage via induction heating. They also release the encapsulated rejuvenator, thereby rejuvenating aged bitumen. These findings indicate that heating systems combined could represent possible asphalt pavement mainten...

BACKGROUND Asphalt workers are exposed to bitumen fume and vapour, and to exhaust from engines and passing traffic. AIMS To assess the occurrence of respiratory symptoms and signs of airflow limitations in a group of asphalt workers. METHODS All 64 asphalt workers and a reference group of 195 outdoor construction workers from the same company participated in a cross-sectional study. Spirome...

We report on dry asphalt roads acting as 'mayfly traps'; that is, they lure swarming, mating and egg-laying mayflies in large numbers. To explain this surprising behaviour, we performed multiple-choice experiments with Ephemeroptera in the field, and measured and compared the reflection-polarization characteristics of an asphalt road and a mountain creek from which mayflies emerge. We show here...

The National Center for Asphalt Technology (NCAT) completed a roundrobin study in March to determine the accuracy and precision of the NCAT asphalt content tester. The Center has conducted research since 1990 to develop this test method for determining asphalt content of hot mix asphalt (HMA) mixtures by ignition (See the fall, 1994, issue of Asphalt Technology News). In the ignition method, a ...

Spreading sodium chloride salt is one of the most effective operations to tackle ice formation on surface a road pavement during cold seasons, thus ensuring safer driving conditions. However, in addition negative environmental impact, solution could influence properties and durability asphalt mixtures. Based these premises, this laboratory study aims characterize mechanical different mixtures e...

This work aims to improve the rutting and fatigue cracking resistance of asphalt binders using selected nanoor micro-sized materials and to shed light on the microstructure changes induced by such modification to asphalt binders. The four modifiers (Nanomer I.44P, carbon microfiber, non-modified nanoclay and polymer modified nanoclay) were added into the control asphalt binder (PG 58-34). The S...

This paper characterizes the effects of artificial short term aging in the laboratory on the rheological properties of virgin 80/100 penetration grade asphalt binder. After several years in service, asphalt mixture started to deteriorate due to aging. Aging is a complex physico-chemical phenomenon that influences asphalt binder rheological properties causing a deterioration in asphalt mixture p...

The incremental health risk for workers of the road-paving sector using rubberized asphalt was assessed based on the outcome of monitoring campaigns carried out during paving operations where both rubberized and standard asphalt were used. The exposure of workers to Polycyclic Aromatic Hydrocarbons (PAHs) released in the asphalt fumes were measured by means of personal samplers and dermal sampl...