Using Reclaimed Asphalt Pavement (RAP) in asphalt mixes has become a common practice in many countries as experience indicated that the recycling of asphalt pavements is very advantageous from different perspectives. Some of the advantages of utilizing RAP include conservation of asphalt and aggregate resources, conservation of energy, and reduction in life-cycle cost. In this study, the suitab...

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...

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 ...

Granite is very widely distributed in the world, but granite an acidic aggregate with poor adhesion to asphalt. In untreated asphalt mixtures, pavement water damage and loose disease are more prominent, affecting service life of level. Enhancing road performance mixture generally improves properties granite. Qingchuan rock asphalt, anti-stripping agent KH5, aliphatic amine AJ-1 two groups compo...

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...

In order to improve the stability and high temperature behavior of rubber asphalt, deep desulfurization stabilized powder SBS are used prepare composite modified asphalt (Hereinafter: asphalt). this paper, gel chromatography permeation test, Fourier transform infrared spectroscopy test dynamic shear rheology were carried out. Comparative tests conducted on base ordinary asphalt. The change mech...

Standard asphalt mixtures for road infrastructures consist of natural aggregate and bitumen. A number of research efforts have successfully investigated the possibility of replacing the conventional aggregate skeleton with industrial by-products such as slag originating from steel production process. However, little is known on the effect of steel slag on the mixtures functional performance and...