The accumulated irreversible deformation in pavement under repeated vehicle loadings will cause fatigue failure of asphalt concrete. It is necessary to monitor the mechanical response of pavement under load by using sensors. Previous studies have limitations in modulus accommodation between the sensor and asphalt pavement, and it is difficult to achieve the distributed monitoring goal. To solve...

The three major distress conditions affecting the performance of asphalt pavements are permanent deformation or rutting, fatigue or load associated cracking, and low temperature or thermal cracking. In an earlier technical topics article (Fall, 1998), we examined the causes of fatigue cracking and the importance of good compaction during construction to help minimize this type of distress. In t...

Recently, the Human Bitumen Study has been finished (Schlüter, 2011). Including 500 workers from more than 80 construction sites it represents the world-wide largest study on adverse health effects caused by bitumen. The study answers a question that has been controversially discussed since decades: Bitumen exposed workers do not show higher levels of DNA damage than unexposed individuals. On t...

OBJECTIVES To characterize temperature-dependent emissions from paving and built-up roofing asphalt (BURA) and to quantify differences in temperature-related concentrations and composition. METHODS Using headspace gas chromatography, 18 polycyclic aromatic hydrocarbon (PAH) emission concentrations were quantified over eight temperatures (120-315°C) for paving asphalt (n = 20) and Types II, II...

heat stress effects on physical and mental health of workers and decreases human function. asphalt workers are both exposed to the heat of their working process and to the sun heat. this study aimed at evaluating thermal stress and its following function fall and the effect of asphalt work on the degree of heat stress and asphalt workers’ physiological parameters. the present study was done at ...

knowledge of the warming or cooling effects induced by asphalt or grass covered areas, may improve our understanding of how thermal stress or thermal comfort is created for workers who have to work outdoors for long hours in warm seasons. for this purpose a field measurements were carried out to know the cooling and warming effects of two adjacent areas, one covered with grass and the other wit...

IN T R O D U C T IO N The major material utilized in the construction of the roads, streets and highways of this country is asphalt. Of the nation’s 3.84 million miles of roads, 1.86 million are paved, hard-surfaced structures. 1.74 million or 94% of these paved roads are constructed of asphalt (Fig. 1). Likewise, within the state of Indiana, 83% or about 9300 miles of the 11,200 miles under th...

Les pŽtroles bruts contiennent de nombreux constituants Ñ dont les asphaltnes Ñ qui peuvent tre adsorbŽs sur les surfaces minŽrales et modifier leurs caractŽristiques de mouillage. Ce qui distingue les asphaltnes des autres constituants de l'huile est leur tendance ˆ s'agrŽger et mme ˆ se sŽparer du pŽtrole en rŽaction ˆ des modifications du pouvoir solvant du pŽtrole. Du fait qu'ils change...