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...

rutting in asphalt concrete is a very common form of distress in asphalt concrete pavement which unfortunately has been incurable to date. one of the prime reasons of rutting is attributed to the behaviour of asphalt binder at elevated temperature. this study has investigated the performance of polypropylene fibres modified asphalt concrete mix against rutting. two types of asphalt concrete sam...

polymer application for the improvement and modification of the bitumen used in roads surfaces has expanded in recent decades. the roads engineers and constructors, therefore, have used the modified bitumen in asphalts helping in this way to increase roads and pavements service life and improving the durability of the roads and asphalts. the bitumen used in asphalt mixture constitutes only a lo...

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...

Putting Research Into Practice Page 10 The National Center for Asphalt Technology (NCAT) has just completed a National Cooperative Highway Research Program (NCHRP) Project: NCHRP 9-11, “Segregation in Hot Mix Asphalt Pavements.” Dr. Mary Stroup-Gardiner was the principal investigator on this project. Segregation has historically been defined to mean localized areas of coarse materials in some a...

asphalt modification/reinforcement has received considerable attention as viable solutions to enhance flexible pavement performance. this is mainly prompted by the unsatisfactory performance of traditional road materials exposed to dramatic increases and changes in traffic patterns. this paper presents the evaluation of fatigue behaviour of nano reinforced stone mastic asphalt mixtures. fatigue...

Using a rejuvenator to improve the performance of asphalt pavement is an effective and economic way of hot asphalt recycling. This research analyzes the rejuvenating effect on aged asphalt by means of a Mortar Transfer Ratio (MTR) test, which concerns the ratio of asphalt mortar that moves from recycled aggregates (RAP aggregates) to fresh added aggregates when aged asphalt is treated with a re...